DRAFT  UGANDA STANDARD  
  DUS  1670  
First  Edition  
2016 -mm-dd 
 
 
 Reference number  
DUS  1670 : 2016  
© UNBS 2016   
  
Padlocks — Specifications  
 DUS  1670: 2016  
ii © UNBS 2016  – All rights reserved  
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2016   
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, including photocopying and microfilm, without prior written 
permission from UNBS.  
Requests for permission to reproduce this document should be addressed to  
The Executive Director  
Uganda National Bureau of Standards  
P.O. Box 6329  
Kampala  
Uganda  
Tel: +256 41 4 333 2 50/1/2/3  
Fax: +256 41 4 286 123  
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  DUS  1670: 2016  
© UNBS 2016  – All rights reserved  iii 
 Contents   
Foreword  ................................ ................................ ................................ ................................ .............................  v 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 Requirements  ................................ ................................ ................................ ................................ .........  5 
4.1 Type  ................................ ................................ ................................ ................................ ........................  5 
4.2 Grade  ................................ ................................ ................................ ................................ ......................  5 
4.2.1  Grade 1  ................................ ................................ ................................ ................................ ...................  5 
4.2.2  Grade 2  ................................ ................................ ................................ ................................ ...................  6 
4.2.3  Grade 3  ................................ ................................ ................................ ................................ ...................  6 
4.2.4  Grade 4  ................................ ................................ ................................ ................................ ...................  7 
4.2.5  Grade 5  ................................ ................................ ................................ ................................ ...................  7 
4.3 Materials  ................................ ................................ ................................ ................................ .................  7 
4.3.1  General  ................................ ................................ ................................ ................................ ...................  7 
4.3.2  Brass  ................................ ................................ ................................ ................................ .......................  8 
4.3.3  Zinc-base alloys  ................................ ................................ ................................ ................................ ..... 8 
4.4 Dimensions  ................................ ................................ ................................ ................................ ............  8 
4.5 Cases  ................................ ................................ ................................ ................................ ......................  8 
4.5.1  General  ................................ ................................ ................................ ................................ ...................  8 
4.5.2  Solid cases  ................................ ................................ ................................ ................................ .............  8 
4.5.3  Laminated cases  ................................ ................................ ................................ ................................ .... 9 
4.5.4  Formed case  ................................ ................................ ................................ ................................ ..........  9 
4.6 Finish  ................................ ................................ ................................ ................................ ......................  9 
4.7 Shackles  ................................ ................................ ................................ ................................ .................  9 
4.7.1  General  ................................ ................................ ................................ ................................ ...................  9 
4.7.2  Design  ................................ ................................ ................................ ................................ .....................  9 
4.7.3  Construction  ................................ ................................ ................................ ................................ ........  10 
4.7.4  Resistance to tension  ................................ ................................ ................................ .........................  10 
4.7.5  Hardness of shackles ................................ ................................ ................................ ..........................  10 
4.8 Lock mechanism  ................................ ................................ ................................ ................................ . 10 
4.8.1  Lock and key variations  ................................ ................................ ................................ ......................  10 
4.8.2  Durability  ................................ ................................ ................................ ................................ ..............  11 
4.8.3  Bolt ................................ ................................ ................................ ................................ ........................  11 
4.9 Keys  ................................ ................................ ................................ ................................ ......................  11 
4.10  Keying of padlocks  ................................ ................................ ................................ ..............................  11 
5 Inspection and methods of test  ................................ ................................ ................................ .........  12 
5.1 Inspection  ................................ ................................ ................................ ................................ .............  12 
5.2 Tension test  ................................ ................................ ................................ ................................ .........  12 
5.3 Locking test  ................................ ................................ ................................ ................................ .........  12 
5.3.1  Apparatus  ................................ ................................ ................................ ................................ .............  12 
5.3.2  Procedure  ................................ ................................ ................................ ................................ .............  12 
5.4 Thickness test for plating  ................................ ................................ ................................ ...................  12 
5.5 Adhesion test for plating  ................................ ................................ ................................ ....................  13 
5.5.1  Apparatus  ................................ ................................ ................................ ................................ .............  13 
5.5.2  Procedure  ................................ ................................ ................................ ................................ .............  13 
5.6 Test for corrosion resistance  ................................ ................................ ................................ .............  13 
5.7 Non-interchangeability test  ................................ ................................ ................................ ................  13 
5.8 Soundness test  ................................ ................................ ................................ ................................ .... 13 
5.9 Load test  ................................ ................................ ................................ ................................ ...............  13 
5.10  Shock impactor  ................................ ................................ ................................ ................................ .... 13 DUS  1670: 2016  
iv © UNBS 2016  – All rights reserved  
 5.11  Shock test  ................................ ................................ ................................ ................................ ............  15 
5.12  Plug pulling test  ................................ ................................ ................................ ................................ .. 15 
5.13  Plug torque test  ................................ ................................ ................................ ................................ ... 15 
5.14  Shackle cutting test  ................................ ................................ ................................ ............................  15 
5.15  Surreptitious entry tests  ................................ ................................ ................................ ....................  16 
5.15.1  Picking or manipulating test  ................................ ................................ ................................ ..............  16 
5.15.2  Cylinder impressioning and decoding tests  ................................ ................................ ....................  16 
5.15.2  Shackle shimming test  ................................ ................................ ................................ .......................  16 
5.15.3  Cylinder drilling and shimming test  ................................ ................................ ................................ .. 16 
5.15.4  Rap test:  ................................ ................................ ................................ ................................ ...............  17 
6 Sampling and inspection  ................................ ................................ ................................ ...................  19 
6.1 Sampling  ................................ ................................ ................................ ................................ ..............  19 
6.1.1  Lot ................................ ................................ ................................ ................................ ........................  19 
6.3 Number of tests and criteria for conformity  ................................ ................................ ....................  19 
6.3.1  For dimensions and finish  ................................ ................................ ................................ .................  19 
6.3.2  For load test and soundness test  ................................ ................................ ................................ ..... 19 
7 Packing and marking  ................................ ................................ ................................ ..........................  20 
7.1 Packing  ................................ ................................ ................................ ................................ ................  20 
7.2 Marking  ................................ ................................ ................................ ................................ ................  20 
7.2.1  Padlocks  ................................ ................................ ................................ ................................ ..............  20 
7.2.2  Keys  ................................ ................................ ................................ ................................ .....................  20 
Annex  A (normative)  Notes to purchasers  ................................ ................................ ................................ ... 21 
Annex  B (Informative)  Quality verification of padlocks  ................................ ................................ ..............  22 
Bibliography  ................................ ................................ ................................ ................................ .....................  23 
 DUS  1670: 2016  
© UNBS 2016  – All rights reserved  v 
 Foreword  
Uganda National Bureau of Standards (UNBS) is a parastatal u nder the Ministry of Trade , Industry and 
Cooperatives established under Cap 327 , of the Laws of Uganda , as amended .  UNBS is mandated to co -
ordinate the elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT  Agreement  of the World Trade Organisation (WTO).  
The work of preparing Uganda Standards is carried out through Technical Committees. A T echnical 
Committee is established to deliberate on standards in a given field or area and consists of key stakeholders 
including government, academia, consumer groups, private sector and other interested parties.  
Draft Uganda Standards adopted by the Tech nical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
The co mmittee responsible for this document is Technical Committee UNBS /TC 4, Mechanical  engineering 
and metallurgy . 
 DRAFT UGANDA STANDARD  DUS  1670: 2016  
 
© UNBS 2016  – All rights reserved  1 
 Padlocks — Specifications  
1 Scope  
This Draft Uganda S tandard specifies the characteristics and requirements , inspection and test methods of 
various types and categories of padlocks.  
2 Normative references  
The following referenced documents referred to in the text in such a way that some or all of their content 
constitutes requirements of this document. For dated references, only the edition cited  applies. For undated 
references, the latest edition of the referenced document (including any amendments) applies.  
ASTM B30 -16, Standard specification for Copper alloys in ingot form  
ISO 11997 -1, Paints and varnishes — Determination of resistance to cycli c corrosion conditions — part 1: wet 
(salt fog)/dry/humidity.  
ISO 15201 , Zinc and Zinc alloys — casting — specifications  
ISO 24153, Random sampling and randomization procedures  
ISO 1554 , Wrought and cast copper alloys — determination of copper content – electrolytic method  
ISO 19598 , Metallic coatings — Electroplated coatings of zinc and zinc alloys on iron or steel with 
supplementary Cr (VI) -free treatment  
ISO 1456,  Metallic and other inorganic coatings — Electrodeposited coatings of nickel, nickel plus ch romium, 
copper plus nickel and of copper plus nickel plus chromium  
ISO 9001 , Quality management systems — Requirements  
3 Terms and definitions  
For the purposes of this document, the followi ng terms and definitions apply.  
3.1  
acceptable  
allowable by the au thority administering this standard, or to the parties concluding the purchase contract, as 
relevant  
3.2  
closed shackle padlock  
padlock in which the body of the padlock encloses or partially encloses the shackle (see figure 3(c) and (d))  
3.3  
extended sha ckle 
shackle that is longer than the shackle normally found on padlocks (see figure 3(b)) DUS  1670: 2016  
2 © UNBS 2016  – All rights reserved  
 3.4  
individually keyed  
descriptive of a padlock that can be opened by means of a specific key only  
3.5  
key combination  
the way in which the sets of tumblers in the lock mechanism of a padlock are arranged in order to 
give each padlock its own individual set of keyway steps  
3.6  
keyed alike [keyed to pass]  
descriptive of padlocks that can all be opened by means of a single key that is not a master key, e.g. 
padlocks t hat can be opened by means of a pass key  
3.7  
key variations  
the different sets of key combinations that can exist without duplication  
3.8  
master key  
key manufactured in such a way that it opens a set of locks that are all identically master keyed  
3.9  
master keyed  
descriptive of a padlock that can be opened by a specific key and by an appropriate master key  
3.10  
normal size  
the overall width and diameter of a padlock at its widest part  
3.11  
paracentric key way  
keyway that has longitudinal ribs and groov es that project beyond its centre to deter lock picking  
3.12  
passing  
any key that operates a lock is set to pass that lock. If all the locks in a set are so made that all may 
be operated by the same key or keys, the locks are set to pass; and the key(s) t o pass the locks  
3.13  
pass key  
key that opens all locks in a set of locks (see 3.5)  
3.14  
shackle protector  
separate, close -fitting shield that covers the lock and shackle and limits attack on the shackle  
3.15  
suite  
set of locks that are all either keyed  alike or identically master keyed  
3.16  
padlock  
detachable and portable lock usually for use with hasps and staples, having a hinged or sliding 
shackle to pass through a staple eye or similar device fixed to the door. The shackle is locked into 
and releas ed from the case of the padlocks by the key operated bolt.  DUS  1670: 2016  
© UNBS 2016  – All rights reserved  3 
 3.17  
chain padlock  
any padlock having permanently attached to it, either:  
a) one end of a length of a stout chain for passing round and securing, fo r example, two stiles of a 
gate;  or 
b) one end of a le ngth of a light safety chain to prevent the padlock from being removed or mislaid.  
3.18  
shackle  
the hinged or sliding part of a padlock which passes through the staple, loop or other device on the door  
3.19   
spring shackle padlock  
padlock in which the sh ackle springs open when the key is turned and which usually incorporates a shackle 
bolt under pressure of second spring so that the shackle becomes locked without the use of a key pushed into 
the closed position  
3.20   
disc tumbler padlock  
any padlock havi ng a disc tumbler mechanism  
3.21   
disc tumbler  
movable detainer in the form of a shaped flat plate, pierced with a slot th rough which the key passes  
3.22   
disc tumbler mechanism  
lock mechanism having a cylindrical plug rotating in a body and having, as i ts principal feature, movable 
detainers in the form of flat plates (disc tumblers) sliding, generally under spring pressure, in transverse slots 
in plug. The disc tumblers project from one end or the other of the slots except when correctly aligned by the 
key. When secured, the projecting tumblers engage in two or sometimes four diametrically opposite 
longitudinal grooves in the sides of plug hole and thus prevent the plug from turning.  
3.23   
disc tumbler key  
bulleted (profiled) key which is flat and has a  long bit, or blade, in which ‘V’ cuts are made on one or both 
edges to operate the tumblers in a disc tumbler padlock  
3.24   
double bitted key  
one which has ‘V’ cuts on both edges of the blade. it may be of following types:  
a) double bitted key with reversib le key entry (with ‘V’ cuts on both edges which are symmetrical); and  
b) double bitted key with irreversible key entry (with asymmetrical ‘V’ cuts on both the edges) . 
3.25   
single bitted key  
one which has ‘V’ cuts on one of the edges of the blade  
3.26   
plun g (rotor)  
part of the disc tumbler padlock into which the key enters and turns  DUS  1670: 2016  
4 © UNBS 2016  – All rights reserved  
 3.27  
pin 
the lower of two solid metal cylinders which together form one of the set of movable detainers in a 
pin tumbler lock.  
3.28  
pin tumbler  
movable detainer consisting of a pin and a detainer  
3.29  
pin tumbler mechanism  
locking mechanism having a plug rotating in a body and as its principal feature, movable detainers in 
the form of pairs of pin tumblers (operating and driver pins) fitting, together with their springs, in ho les 
in the plug and body. In the secured position the drivers bridge interface between the body and plug 
thus preventing the plug from turning.  
The key way is an axial radial slot in the plug. Insertion of the correct key lifts the pins and driver 
against their springs and positions them so that the joint faces between the pin and driver lie on the 
interface between the plug and body thus permitting the plug to turn.  
3.30  
locking bolt or shackle locking balls  
bolt or locking balls with in the body of the p adlock, which engages with the notch in the shackle 
when locked. In some padlocks there are two locking bolts or locking balls  
3.31  
key with indents  
Key wit indents is one, which has blind indents on each side of the blade, and/ or each side of the 
edge.  
A key with indents is generally of the following types:  
a) reversible key entry (with indents on both sides and edges, which are symmetrical). It may or 
may not be profiled.  
b) a key with indents may operate two or more number of rows of pins as desired  
3.32  
lever padlocks  
padlock having as its principal feature a lever mechanism for operating the lock.  
3.33  
lever  
flat movable detainer pivoted at one end or sliding guide and perforated by a shaped slot or gating 
which in the secured position prevents axial/ an gular movement/rotation of the bolt of the lock but 
which, when lifted by its initial contact with a rotating key bit allows the bolt stump to pass through the 
gating thus enabling the bolt to be thrown or withdrawn and then falls back to the secured posit ion as 
key passes out of contact.  
3.34  
lever mechanism  
lock mechanism having as its principal one or more levers to work as detainers  
3.35  
driver  
upper of two small solid metal cylinders, which together form one of the set of movable detainers in a 
pin tumbler lock  DUS  1670: 2016  
© UNBS 2016  – All rights reserved  5 
 3.36  
Impressioning  
non-destructive, covert method of creating a working key for a lock without picking or disassembly  
4 Requirements  
4.1 Type  
A padlock shall be of one of the following types, as required:  
a) type CP — a padlock that has a pin tum bler mechanism , 
b) type CD — a padlock that  has a disc tumbler mechanism , and 
c) type LP — a lever padlock . 
4.2 Grade  
A padlock shall be of one of the categories indicated below, as required . 
4.2.1  Grade  1 
A padlock (see figure 1) that has  
a) not more than 4 key p ins; 
b) key combinations of not more than 500 key variations; and  
c) a single locking bolt.  DUS  1670: 2016  
6 © UNBS 2016  – All rights reserved  
 
 
Figure 1 — Cross -section of a padlock, showing important components  
4.2.2  Grade  2 
A padlock (see figure 1) that has:  
a) at least 4 to 6 k ey pins;  
b) key combinations of at least 2 000 key variations;  
c) anti-picking pins (anti -picking rollers);  
d) anti-picking plates, or stop pins, to prevent a probe from reaching the locking bolt(s); and  
e) single or double locking bolts  
4.2.3  Grade  3 
A padloc k (see figure 1) that has:  
a) at least 5 key pins;  DUS  1670: 2016  
© UNBS 2016  – All rights reserved  7 
 b) key combinations of at least 5 000 key variations;  
c) anti-pickin g pins (anti -picking rollers);  
d) anti-picking plates to prevent a probe from reaching the locking bolts; or  
e) anti-picking pins (anti -picking rollers) and anti -picking plate;  
f) double locking bolts; and  
g) a brass cut key.  
4.2.4  Grade  4 
A padlock (see Figure 1) that has:  
a) at least 5 key pins;  
b) key combinations of at least 7 000 key variations;  
c) anti-picking pins (anti -picking rollers);  
d) anti-picking plates, or stop pins , to prevent a probe from reaching the locking bolt(s);  
e) a closed shackle or a shackle protector to limit attacks on the shackle; and  
f) a body width of at least 50 mm.  
If so required, keys shall be non -removable in the unlocked position of the shackle (see 4.8.3).  
4.2.5  Grade  5 
A padlock (see Figure 1) that has  
a) at least 5 key pins;  
b) key combinations of at least 8 000 key variations;  
c) anti-picking pins (anti -picking rollers);  
d) anti-picking plates, or stop pins, to prevent a probe from reaching the locking bo lt(s);  
e) a closed shackle or a shackle protector to limit attacks on the shackle; and  
f) a body width of at least 50 mm.  
If so required, keys shall be non -removable in the unlocked position of the shackle (see 4. 9.3).  
NOTE 1  Grade or security grade is often  referred to as  grade . 
NOTE 2  A cross -section of a padlock showing the most important components is given in Figure 1 
4.3 Materials  
4.3.1  General  
Each metal used in a padlock shall be uniform in quality, chemical composition, hardness and strength, and 
shall be free from blowholes, scale, cracks and other deleterious defects. When anti -corrosion padlocks are DUS  1670: 2016  
8 © UNBS 2016  – All rights reserved  
 required, shackles may be made of a material that is softer than casehardened steel or stainless steel, to 
ensure the durability of the padlock. The in tegrity of the system shall, however, not be compromised in any 
way. 
4.3.2  Brass  
Brass shall comply with the requirements of ASTM B30 -16. 
4.3.3  Zinc-base alloys  
Zinc-base alloys shall comply with the  requirements for ISO 15201.  
4.4 Dimensions  
A padlock sha ll be of one of the nominal sizes given in column 1 of Table 1, as required, and the diameter of 
the shackle shall be as given in column 2. Column 3 of the Table is related to the test given in 6.2.  
Table 1 — Nominal sizes of padloc k 
Nominal size  
mm Minimum shackle 
diameter  
mm Tension  
kN 
25 4.0 1.0 
30 5.0 1.5 
40 6.0 3.0 
45 8.0 5.0 
50 8.0 5.0 
55 8.0 5.0 
60 10.0 10.0 
65 11.0 11.0 
70 12.0 15.0 
75 12.0 15.0 
90 12.0 15.0 
 
4.5 Cases  
4.5.1  General  
Cases shall be solid, laminated  or formed, as required  
4.5.2  Solid cases  
A solid case shall be made in one piece and the only openings shall be for inserting the shackle and the lock 
mechanism and, if necessary, for drainage. The diameter of a drainage hole shall not exceed 3 mm. Any ot her 
openings required during assembly of the padlock shall be individually plugged by riveting or pressing (or 
both).  DUS  1670: 2016  
© UNBS 2016  – All rights reserved  9 
 4.5.3  Laminated cases  
A laminated case shall be assembled from metal laminates that, if not of inherently corrosion resistant metal, 
are individually plated before assembly. All laminates shall be so riveted (or riveted and brazed) as to render 
the case substantially solid and such that it will not be possible to dismantle the padlock by filing off the rivet 
heads.  
4.5.4  Formed case  
A formed  case shall consist of shaped metal plates covering a sintered metal or similar body.  
Steel cases around locks shall have been case -hardened to a depth of between 0.15 mm and 0.50 mm and to 
a Vickers hardness in the range 650 HV to 850 HV  or Rockwell C har dness in the range of 56.5 HRC to 64.5 
HRC , measured subject to the maximum test loads given in Table 2.  
4.6 Finish  
4.6.1  The method of manufacturing of padlocks and its components is left to the manufacturer, however, it 
shall meet the requirements laid d own in this standard.  
4.6.2  All components of the padlocks and keys shall be finished smooth to minimize frictional resistance in 
their working.  
4.6.3  The body of the padlock, if required, shall be suitably painted/plated. The shackle and keys for brass 
padlocks shall, however be finished bright.  
4.6.4 Steel components shall be suitably protected to resist corrosion. The electroplated coating of nickel 
plus chromium or zinc on iron and steel wherever specified, shall be done in accordance with ISO 1456, ISO  
19598 respectively. The electroplated coating of copper plus nickel plus chromium shall be done in 
accordance with ISO 1456  
4.6.5  When the thickness of the plating is determined in accordance with 5.4, it shall be one of the 
following, as required:  
a) at lea st 10 µm for locks intended for use in inland areas (standard conditions);  
b) at least 20 µm for locks intended for use in severe conditions.  
4.6.6  When a padlock is tested in accordance with 5.5, there shall be no separation of the plating from the 
underlyin g metal.  
4.6.7  When a padlock intended for use in severe conditions (see 4.6.5(b)) is tested in accordance with 5.6, 
the plating shall show no sign of discoloration or rust or other failure.  
4.7 Shackles  
4.7.1 General  
A shackle shall be of the closed, the normal, the extended or the removable type, as required.  
4.7.2 Design  
Unless a pull -out, key -locking design is required, shackles shall be of a spring -opening, self -locking design.  
NOTE 1  A pull -out, key -locking design refers to a shackle that is spring lo aded, that has to be pulled open and the 
padlock cannot be locked without use of the key.  DUS  1670: 2016  
10 © UNBS 2016  – All rights reserved  
 NOTE 2  A spring -opening, self -locking design refers to a shackle that is not spring loaded, that opens by itself when 
the key is turned and the padlock can be locked without use of the key.  
4.7.3 Construction  
Shackles shall lock either at the toe or at the toe and the heel, as determined by the grade, and the slot(s) in 
the shackle shall be so formed as to securely engage the locking bolt(s).  
4.7.4 Resistance to tensio n 
When a padlock is tested in accordance with 5.2, using the relevant loadings given in column 3 of Table 1, the 
shackle shall not release from the locking bolt(s), and the shackle pivot, when relevant, shall not separate 
from the shackle or from the case.  
4.7.5 Hardness of shackles  
4.7.5.1 Surface hardness  
The surface of shackles shall have been case -hardened to a Vickers hardness in the range 650 HV to 850 HV 
or Rockwell C hardness in the range of 56.5 HRC to 64.5 HRC (the load depending on the case depth , as 
indicated in 4.6.5.2) and to the following depths:  
a) material of diameter in the range 2.5 mm to 5.0 mm shall have been case -hardened to a depth of 
between 0.10 mm and 0.15 mm;  
b) material of diameter 6.0 mm shall have been case -hardened to a depth of betw een 0.25 mm and 0.30 
mm; 
c) material of diameter in the range 8.0 mm to 13.0 mm shall have been case -hardened to a depth of 
between 0.30 mm and 0.35 mm;  
4.7.5.2 Maximum hardened test load  
The maximum allowable load for Vickers hardened testing shall be as fol lows. 
Table 2 — Test loads for Vickers hardness testing  
Case depth  
mm Maximum allowable load  
Kg 
0.1 to 0.15  2.5 
0.15 to 0.25.  5.0 
0.25 to 0.35  10.0 
 
The duration of loading shall be between 10 s and 15 s.  
The shackle shall be te sted on a flat surface.  
4.8 Lock mechanism  
4.8.1 Lock and key variations  
The key variations for a particular padlock shall, without duplication of a particular step height on a single key, 
be as given in Table 3. DUS  1670: 2016  
© UNBS 2016  – All rights reserved  11 
 Table 3 — Key varia tions  
Grade of padlock  Minimum number of variations  
1 500 
2 2000  
3 5000  
4 7000  
5 8000  
 
4.8.2 Durability  
After a padlock has been tested in accordance with 5.3, it shall be possible to lock (when relevant) and unlock 
it by using the duplicate key (if supplied) . 
4.8.3 Bolt 
4.8.3.1 The design and construction of the padlock shall be such that it is not possible to release the 
locking bolt by inserting a probing device between the shackle and the case of the padlock.  
4.8.3.2 The tension in the bolt spring s, when relevant, shall be such as to prevent any movement of the 
closed shackle that could compromise the security of the lock.  
4.8.3.3 The end face(s) of the locking bolt(s) shall be normal to the bolt axis and flat, and shall have a 
width of at least 20  % of the diameter of the bolt . 
NOTE  Although the end faces of some locking bolts are tapered, they should not be tapered to a point  
4.9 Keys  
4.9.1 Any two steps of a key shall have a minimum difference of 0.4 mm in step height, to prevent the key 
from pas sing when adjacent heights are transposed.  
4.9.2 Duplicated step heights may be used in a key system provided that each lock mechanism complies 
with the requirements of 4. 8.1 and 4 .9.1. 
4.9.3 If so required, keys shall be non -removable in the unlocked posi tion of the shackle  
4.9.4 A padlock of grade  3 or 4 may have a paracentric keyway or other acceptable shape of keyway.  
4.10 Keying of padlocks  
4.10.1 Padlocks supplied in sets shall be either individually keyed or, to pass, keyed alike, as required, and 
shall, when so required, be master keyed  
4.10.2 The number of padlocks controlled by an individual master key shall be as required  
4.10.3 Unless otherwise required, all keys shall be supplied in duplicate  DUS  1670: 2016  
12 © UNBS 2016  – All rights reserved  
 5 Inspection and methods of test  
5.1 Inspection  
Visua lly examine each padlock for compliance with all the relevant requirements of this standard for which 
tests to assess compliance are not given in 5.2 to 5.15 (inclusive)  
5.2 Tension test  
Clamp the padlock firmly in a vertical position in a vice. Apply, alo ng the vertical centre -line of the padlock 
under test, the appropriate force given in column 3 of table 1 between the shackle and the case and maintain 
the force for 5 min. Check for compliance with 4.8.3.1 . 
5.3 Locking test  
5.3.1 Apparatus  
A device, capab le of carrying out the following cycle of operations at a rate of 15 to 20 cycles per minute:  
a) inserting the key;  
b) unlocking the padlock;  
c) opening the shackle;  
d) closing the shackle;  
e) (where relevant) locking the padlock;  
f) removing the key.  
5.3.2 Procedure  
5.3.2.1 Position the padlock in its normal working position (i.e. vertical).  
5.3.2.2  Submit the padlock to the relevant of the following cycles of operation:  
a) 12 000 cycles of operation for grade 4 and 5 padlocks;  
b) 9 000 cycles of operation for grade  3 padlocks;  
c) 6 000 cycles of operation for grade  2 padlocks; and  
d) 3 000 cycles of operation for grade  1 padlocks.  
Ensure that padlocks are lubricated with silicon lubricant or graphite after every 2 000 cycles  
5.3.2.2  Check for compliance with 4. 8.2 
5.4 Thickness test f or plating  
Use an acceptable electrochemical method to determine the thickness of the zinc, cadmium, copper -nickel or 
chromium on plated components and check for compliance with 4.6.5 . DUS  1670: 2016  
© UNBS 2016  – All rights reserved  13 
 5.5 Adhesion test for plating  
5.5.1 Apparatus  
A hacksaw and a blade tha t has 90 to 100 teeth per 100 mm.  
5.5.2 Procedure  
Saw through the plating on plated components and examine the edges of the cuts for compliance with 4. 6.6. 
5.6 Test for corrosion resistance  
Use the procedure given in ISO 11997 -1 with an exposure time of 16  h, and check for compliance with 4.6.7 . 
5.7 Non-interchangeability test  
For the purpose of testing non -interchangeability, the padlocks of each size in batches shall be presented for 
non-interchangeability test for that size or part thereof, 15 in case of  sizes up to 40  mm and 22 mm in case of 
higher sizes of padlocks shall be selected in such a manner that the arrangement of the wards of their keys is 
nearly similar, that is, the ward of the keys differ from each other slightly. The padlocks with their ke ys so 
selected shall be tested for non -interchangeability by using each key with all other padlocks. If none of the 
keys works or opens any other padlock then the batch from which the padlocks have been selected shall be 
considered to have passed the non -interchangeability test.  
5.8 Soundness test  
Each padlock in the locked condition shall be firmly  held by the shackle and five sharp blows from  height of 
600 mm shall be given on a 75 mm thick  lead block with that side of the padlock on which the  shackle is 
riveted. The padlock shall then be opened  and the above test is repeated by striking five sharp  blows on the 
opposite side of the padlock. During or  on completion of the test the padlock shall not open or  show any sign 
of damage or defective functioning.  
5.9 Load test  
The body of the sample padlock shall be held in the  clamping jaws in the locked condition with shackle  
engaged in a suitable hook or eye in a vertical position.  The tensile load as mentioned in Table  1 shall be 
gradually  applied to the padlock  through the hook without jerks  and maintain the force for 1 min. The padlock 
shall not fail under the load.  
5.10 Shock impactor  
5.10.1  Provide a fixture as illustrated in Figure 2 which allows the weights described in 5.10.2  to be properly 
guided to strik e the anvil rod which will be placed in direct contact with the top surface of a padlock using the 
mounting block described in 5.10.3 . DUS  1670: 2016  
14 © UNBS 2016  – All rights reserved  
 
 
Figure 2 — Shock impactor  
Key 
1. Base plate  
2. Shaft cross support  
3. Support tube  
4. Weight guide shaft  
5. Anvil rod  
6. Stop collar  
7. Mounting block  DUS  1670: 2016  
© UNBS 2016  – All rights reserved  15 
 8. Mounting block base  
9. Mounting pin  
5.10.2  Make a set of weights as shown in Figure 2, with a central hole in each that allows the weight selected 
to free fall and strike the top surface of the anvil rod.  
5.10.3  Make a moun ting block that will support the specimen on the mounting block when being subjected to 
the required shock load as given in Table 4.  
Table 4 — Required values  for different tests  
Forcing tests  Grades  
1 2 3 4 5 
Shock test blows  5 5 5 5 5 
Shock test weights, 
(kg) 1 2 3 4 5 
Shock test heights, (m)  1 1 1 1 1 
Plug pull test, (N)  1000  1500  2000  3000  6000  
Plug torque test, (Nm)  10 15 20 25 30 
Shackle cutting force 
test, (N)  4450  9000  13500  18000  31 000  
5.11 Shock test 
Using the imp actor drop the weight as given in Table 4 the required number of times as in Table 4 on the top 
of the locked padlock case. Failure occurs if the padlock opens.  
5.12 Plug pulling test  
Drill the keyway with a number 20 (4.0 mm.) diameter drill and insert a Type AB No. 12 screw at least 19 mm 
deep. Apply the required tension as given in Table 4 axially between the case and the installed screw. Failure 
occurs if the cylinder plug or cylinder assembly completely separates from the case, or if the padlock can be  
opened by manipulation with a screwdriver at the conclusion of the test.  
5.13 Plug torque test  
5.13.1  Install the padlock in a rigid fixture such as a vice to support it firmly but not restrict free rotation of the 
plug in the cylinder.  
5.13.2  Insert a bl ade type tool into the keyway, so that a torque load as given in Table 4 can be applied to 
the plug. Failure occurs if the padlock opens.  
5.14 Shackle cutting test 
Shackles shall withstand cutting through when 2 shearing blades made of a steel hardened to a minimum 
Rockwell C hardness of 50 HRC, are used in conjunction with the blade positioning holder, is placed in a 
tensile loading device having a compression load capability and compressed with the required force as given 
in Table 4. Failure occurs if the  shackle is cut through.  DUS  1670: 2016  
16 © UNBS 2016  – All rights reserved  
 5.15 Surreptitious entry tests  
5.15.1  Picking or manipulating test  
5.15.1.1  Cylinders in padlocks shall resist picking for the required time specified in Table 5. Combination 
padlocks shall resist manual manipulation for the speci fied time.in Table 5  
Table 5 — Surreptitious entry tests required values  
Surreptitious entry tests  Grades  
1 2 3 4 5 
Picking or manipulation , 
(min)  0.5 1 2 4 8 
Bump key attack , (min)  2.5 5 7.5 10 12.5  
Impressioning or 
Decoding, (min)  N/A N/A 2 4 8 
Shackle shimming test , 
min 0.5 1 2 4 8 
Drilling and shimming , 
(min)  N/A N/A N/A 4 8 
Rapping, (min)  N/A N/A 2 4 8 
 
5.15.1.2  Padlocks submitted for test containing pin tumblers shall be loaded using one of the three or four 
mid-range bittings available unless such a combination would not normally be supplied as a stock product. 
Padlocks containing other tumbler elements shall be loaded using maximum ranges. If lock design and 
cylinders used are the same in several different sizes of pa dlocks submitted for testing, only a total of five 
samples of any size or sizes need to be tested.  
5.15.1.3  The tools used for this test shall be manual manipulating tools required by the operator, providing 
no visible marks are left detectable by the unai ded eye.  
5.15.2 Cylinder impressioning and decoding tests  
5.15.2.1 Cylinders shall resist successful impressioning and decoding for the required time in Table 5. 
5.15.2 .2 Padlocks with cylinders submitted for test shall be loaded in accordance with 5.15.1. 2. 
5.15.2  Shackle shimming test  
Insert any shim stock selected that can be inserted in the clearance between the shackle and the case in 
either or both of the case shackle holes of a locked padlock and manipulate for the time in Table 5  
5.15.3  Cylinder drilling and shimming test  
5.15.3.1  Use hand -held tools.  
5.15.3 .2 Load cylinders in accordance with 5.15.1.2.  
5.15.3.3  Cylinders in locked padlocks hanging from a hasp shall resist drilling and shimming for the time 
specified in Table 5. Results of the drilli ng test shall not be obvious to the unaided eye.  DUS  1670: 2016  
© UNBS 2016  – All rights reserved  17 
 5.15.4  Rap test: 
5.15.4.1  Use hand -held tools.  
5.15.4.2  Padlocks shall resist successful rapping on the cylinder and case for the specified time in Table 5.  
 
Figure 3 — Examples of different shackles found on padlocks  DUS  1670: 2016  
18 © UNBS 2016  – All rights reserved  
 
 
Figure 4 — Typical shapes of lever padlocks  
 
 
Figure 5 — Key with indents  
 DUS  1670: 2016  
© UNBS 2016  – All rights reserved  19 
 6 Sampling and inspection  
6.1 Sampling  
6.1.1 Lot 
In any consignment, all the locks of the same type, same size, and manufactured from the similar materials 
under similar conditions of manufacture shall be grouped together to constitute a lot.  
For ascertaining the conformity of the lot to the requirements of this standard, the sample of padlocks  shall be 
and tested separately for each lot.  
6.2 The number of sample locks to be selected at random from a lot shall depend upon the size of the lot 
and shall be in accordance with Table 5. 
6.2.1 The padlocks in the samples shall be selected at random fr om the lot. In order to ensure the 
randomness of selection, procedures given in ISO 24153 may be followed.  
6.2.1.1  In case padlocks are packed in boxes, 20 percent of the boxes, subject to a minimum of two, shall 
be opened and equal number of padlocks shal l be taken from each box so as to constitute the required 
sample size.  
6.3 Number of tests and criteria for conformity  
6.3.1 For dimensions and finish  
The padlocks selected according to 6.2 shall be inspected for dimensions, workmanship and finish. The lot  
shall be considered as conforming these requirements if the number of padlocks failing in any one or more of 
the requirements does not exceed the permissible number of defective padlocks given in Table 5. 
6.3.2 For load test and soundness test 
From the lo t found conforming under 6.3.1 a subsample shall be drawn in accordance with Table 5 and tested 
for load test and soundness test consecutively.  
The lot shall be considered as conforming to the requirement of load and soundness test if the number of 
sample padlocks failing in any of the two tests does not exceed  
Table 6 — Sample size and criteria for conformity  
Lot Size  
 Dimensions  and Finish  Tests 
Sample Size  Permissible No. of Defective 
Padlocks  Sub-sample  Permissible No. 
of Defe ctive 
Locks  
up to 50  8 o 2 0 
51 to 150  13 0 2 0 
151 to 300  20 0 2 0 
301 to 500  32 1 3 0 
501 to 1000  50 2 5 0 
I 001to 3000  80 3 10 0 
3001 to 10000  125 5 15 1 
10001 and 
above  200 7 20 2 DUS  1670: 2016  
20 © UNBS 2016  – All rights reserved  
 7 Packing and marking  
7.1 Packing  
Each padlock shall be so pack ed as to be protected from damage during normal handling, transportation and 
storage. Only padlocks of the same type, grade and nominal size shall be packed together in a bulk container  
7.2 Marking  
7.2.1  Padlocks  
Each padlock shall be legibly and indelibly  marked with the following information:  
a) manufacturer’s name, or trade name  or trade mark,  
b) year of manufacture (if specified by the purchaser),  
c) grade,  
d) nominal size of the padlock, and  
e) serial number of the padlock.  
7.2.2  Keys  
Each key shall bear the following information in legible and indelible marking:  
a) the manufacturer’s name or trade name or trade mark; and  
b) the country of origin.  
6.2.3  Containers  
Each bulk container of padlocks shall bear the following information in legible and inde lible marking:  
a) the manufacture’s name or trade name or trade mark;  
b) the type of padlock;  
c) the grade of padlock;  
d) where applicable, an indication that the padlock is suitable for use in severe conditions, i.e. that stainless 
steel or some non -corro dible material has been used for the padlock;  
e) the nominal size of the padlock; and  
f) any other information required  DUS  1670: 2016  
© UNBS 2016  – All rights reserved  21 
 Annex  A 
(normative)  
 
Notes to purchasers  
The following requirements shall be specified in tender invitations and in each order or contra ct 
a) the type and grade  of padlock;  
b) the nominal size of padlock;  
c) the type of case;  
d) the type of shackle;  
e) the design of padlock;  
f) whether the keys are to be removable or non -removable in the unlocked position of the shackle;  
g) whether the padlocks are to be indiv idually keyed or keyed alike;  
h) whether the padlock are to be master keyed;  
i) the number of padlocks to be controlled by an individual master key;  
j) if the keys are to be supplied in duplicate ;  
k) the finish of the padlock;  
l) whether the padlock are for use in stand ard conditions or in severe conditions;  and 
m) additional makings required . DUS  1670: 2016  
22 © UNBS 2016  – All rights reserved  
 Annex  B 
(Informative)  
 
Quality verification of padlocks  
When a purchaser requires quality verification on an ongoing basis of shade netting, it is suggested that, 
rather than to the e valuation of the final product only, he also direct his attention to the quality management 
system applied by the manufacturer. In this connection it should be noted that ISO 9001 covers the provision 
of an integrated quality management system  DUS  1670: 2016  
© UNBS 2016  – All rights reserved  23 
 Bibliography  
[1] SANS 1533 , Padlocks.  
[2] IS 15275:2003 , Padlocks — Specification ). 
[3] ASTM F883 – 13, Standard Performance Specification for Padlocks  
 DUS  1670: 2016  
© UNBS 2016  – All rights reserved  25 
 Certification marking  
Products that conform to Uganda standards may be marked with Uganda National Bureau of Stand ards 
(UNBS) Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is governed by the Standards Act, and the Regulations made 
thereunder. This mark can be used only by those licensed under the certification mark scheme operat ed by 
the Uganda National Bureau of Standards and in conjunction with the relevant Uganda Standard. The 
presence of this mark on a product or in relation to a product is an assurance that the goods comply with the 
requirements of that standard under a syst em of supervision, control and testing in accordance with the 
certification mark scheme of the Uganda National Bureau of Standards. UNBS marked products are 
continually checked by UNBS for conformity to that standard.  
Further particulars of the terms and conditions of licensing may be obtained from the Director, Uganda 
National Bureau of Standards.  
 
 DUS  1670: 2016    
 
ICS 91.190  
Price based on nn pages  
© UNBS 2016 – All rights reserved