MEDC 02 (402) DTZS  
1 
  
 
DRAFT TANZANIA STANDARD  
 
 
 
Padlocks and padlock fittings – Specification  
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
              TANZANIA BUREAU OF STANDARDS  
 
 
© TBS 2 021                                                                                                    First  Edition 20 21 
  MEDC 02 (402) DTZS  
2 
 This Tanzania Standard was published under the authority of the Board of Directors of Tanzania 
Bureau of Standards on 2021 -XX-YY. 
 
Tanzania Bureau of Standards (TBS) is the statutory national standards body for Tanzania 
established under the Standards Act No. 3 of 1975, repealed and replaced by the Standards Act No. 
2 of 2009.  
The Mechanical Engineering Divisional Standards Committee,  under whose supervision this Tanzania 
Standard was prepared, consists of representatives from the following organizations:  
 
College of Engineering and Technology, University of Dar es Salaam  
National Institute of Transport  
Mechanical Engineering Industries Development Agency  
Ministry of Works  
Weights and Measures Agency  
Tanzania Industries Research Development Organization  
National Development Corporation  
ALAF Limited  
 
The following organizations were directly represented on the Technical Committee entrusted with the 
preparation of this Tanzania Standard:  
 
College of Engineering and Technology, University of Dar es Salaam  
ALAF Limited     
Dar es Salaam Institute of Technology     
National Development Corporation  
Tanzania A utomotive Technology Centre  
MM Integrated Steel Mills  
Trans Auto Parts Company Limited  
 
 
 
 
 
 
 
 
Tanzania Bureau of Standards P O Box 9524  
Dar es Salaam  
Tel: +255 (22) 2450206/2450949/2450298  
Fax: +255 22 2450298  
E-mail: info@tbs.go.tz  
 
 
ISBN:  978-9987 -11-368-2 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   MEDC 02 (402) DTZS  
3 
 Padlocks and padlock fittings – Specification  
0 Foreword  
Padlocks are portable locks  used to protect against theft,  vandalism,  sabotage,  espionage,  
unauthorized use, and harm. They are designed to protect against some degree of forced and 
surreptitious entry. The padlock and padlock fittings must have several important features to be 
effective. These features needs to be standardized so as to meet and address all that factions 
mentioned above. In making sure that all performance requirements such as strength, security, 
corrosion resistivity are meet, TBS come up with this Tanzania Stand ard TZS 1413: 2021 , Padlocks 
and padlock fittings – Specification  and test methods.  
 
This Tanzania Standard has been prepared by the Metals and Structures Technical Committee under 
the supervision of the Mechanical Engineering Divisional Standards Committe e. 
 
For the purpose of deciding whether a particular requirement of this Tanzania Standard is complied 
with, the final value observed or calculated expressing the result of a measurement or test shall be 
rounded off in accordance with TZS 4 (see clause 2).  
 
In preparation of this Tanzania Standard the assistance was drawn from:  
 
BS EN 12320: 2012, Building hardware – Padlocks and padlock fittings – Requirements 
and test methods , published by BSI Standards Limited.  
 
ASTM F883 – 13, Standard Performance Specification for Padlocks , published by 
American Society for Testing and Materials.  
 
IS 15275:2003, Padlocks — Specification , published by Bureau of Indian Standards.  
  
1 Scope  
This Tanzania Standard specifies requirements, test methods and sampling of  padlocks and padlock 
fittings used on buildings and general use. It covers  performance and other requirements for 
dimension, strength, security, durability, material and corrosion of padlocks and padlock fittings.  
The specification s cover  environmental, operational  and security requiremen ts for padlocks. Included 
are function descriptions, cycle tests, operational tests, environmental tests, forcing tests, and 
surreptitious entry tests.  
This specification describes and grades various levels of performance  to provide users of the 
specification with criteria upon which to select suitable padlocks.  Six levels of performance are 
described in this specification with Grade 1 the lowest and Grade 6 the highest.  
Tests described are laboratory tests and although th ey simulate field conditions as to attacks or the 
environment, they do not duplicate these conditions. Tests described are repeatable in the laboratory.  
 
2 Normative references  
This Tanzania Standard incorporates by dated or undated reference, provisions f rom other 
publications. These normative references are cited at the appropriate places in the text and the 
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any 
of these publications apply to this Tanzania St andard only when incorporated in it by amendment or 
revision. For undated references the latest edition of the publication referred to applies (including 
amendments).  
ISO 1456 , Metallic and other inorganic coatings — Electrodeposited coatings of nickel, nickel plus 
chromium, copper plus nickel and of copper plus nickel plus chromium    MEDC 02 (402) DTZS  
4 
 ISO 2081,  Metallic and other inorganic coatings — Electroplated coatings of zinc with supplementary 
treatments on iron or steel  
ISO 19598 , Metallic coatings — Electroplated co atings of zinc and zinc alloys on iron or steel with 
supplementary Cr(VI) -free treatment  
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests  
 
3 Terms and Definitions  
For the purpose of this standard the fo llowing definitions shall apply:  
3.1 acceptance testing  
to assure by documented testing that a padlock meets specific tests of Specification as agreed to by 
the buyer and seller.  
3.2 bump key  
lock picking key with uniform steeples between cuts that is forced further into the lock via imp act. 
3.3 cam  
lock or cylinder component which transfers the rotational motion of a key or cylinder plug to the bolt 
works of a lock.  
3.4 case  
housing or body of a lock or latch.  
3.5 certified  
to assure by documented testing that a padlock meets all test re quirements appropriate to its grading.  
3.6 clevis  
fastener attached to a padlock case or shackle for connection of a chain, designed to prevent 
displacement of a padlock.  
3.7 cylinder  
complete operating unit which usually consists of the plug, shell, tumbl ers, springs, plug retainer, a 
cam/tailpiece or other actuating device, and all other necessary operating parts.  
3.8 cylinder bitting  
group of numbers that represent the bitting of a key or the tumblers, or both, of a lock or cylinder.  
3.9 decode  
to determ ine a key combination by physical measurement of a key or cylinder parts, or both.  
3.10 heel  
part of a padlock shackle that normally is retained in the case when in the unlocked position.  
3.11 impression technique  
means of fitting a key directly to a locke d cylinder by manipulating a blank in the keyway and cutting 
the blank where the tumblers have made marks.   
3.12 keyway  
openin g in a lock or cylinder that is shaped to accept a key bit or blade of a proper configuration.    MEDC 02 (402) DTZS  
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 3.13 lock bumping  
picking  technique that utilizes a configured key forcefully impacted into the keyway.  
3.14 padlock  
detachable and portable lock with a shackle that locks into its case. Components  performing the same 
purpose of a shackle but differing in design are sometimes  used  instead of a shackle.  
3.15 pick  
to mani pulate tumblers in a keyed lock mechanism through the key way, without obvious damage, by 
means other than the specifically designed key.  
3.16 plug  
part o f a cylinder which contains the keyway, with tumbler chambers u sually corresponding to those  
in the cylinder shell.  
3.17 plug retainer  
cylinder component that secures the plug in the shell.  
3.18 pull bump key  
lock p icking key that must be pulled from the lock one space position between impacts.  
3.19 push bump key  
lock picking key that centers itself after each impact.  
3.20 rap  
to unlock a p adlock shackle from its case by striking the case in order to disengage the locking 
mechanism.  
3.21 removable cylinder  
cylinder that can be removed from a locking device by a key or tool, or both.  
3.22 shackle  
part of a  padlock that passes through an opening in an object or fits around an object and is ultimately  
locked into the case.  
3.23 shroud  
material  on a padlock body specifically added to protect the shackle from physical attack.  
3.24 tailpiece  
actuator att ached to or part of the rear of the cylinder.  
3.25 toe  
part of a p adlock shackle that is normally released from the case in the unlocked position.  
3.26 tumbler  
movable obstruction of varying size and configuration in a lock or cyl inder that makes direct contact 
with the key or another tumble r and prevents an incorrect key or torqueing  device from activating the 
lock or other mechanism.  
   MEDC 02 (402) DTZS  
6 
 4 Requirements  
4.1 Workmanship and finish  
The method of manufacturing of padlocks and its components is left to the manufacturer;  however, it  
shall meet the requirements laid down in this standard. All components of the padlocks and keys shall 
be finished smooth to minimize frictional resistance i n their working.  
The body of the padlock, if required, shall be suitably painted/plated. The shackle and keys for brass 
padlocks shall, however be finished bright.  
Steel components shall be suitably protected to resist corrosion.  
4.2 Dimension s and shapes  
4.2.1 Padlocks having sizes other than those specified in  Table 1 may also be permitted as agreed to 
between the purchaser and the supplier, but the other provisions in this standard will be generally 
adhered to.  The typical shape and design of padlocks and their designs are indicated for information 
in Annex A.  
Table 1: Dimensions of Lock and Shackle  
Nominal Size of Lock, mm  
 Minimum Shackle Diameter, mm  
25 4 
30 4 
40 5 
45 6 
50 6 
55 8 
60 8 
65 9 
70 10 
75 11 
85 12 
90 12 
Note:  The tolerances for size of lock shall be ± 2mm. 
 
4.3 Classification  
4.3.1 General  
Classification shall be in form of a four digit code as shown below:  
Table 2: Classification  
1 2 3 4 
Category of 
use Durability  Corrosion 
resistance  Security  
 
4.3.2 Category of use (first digit)  
Grade 1: for use by people with high incentive to exercise care and with small chance of misuse .  
4.3.3 Durability (second digit)  
Grade 0: no requirements .    MEDC 02 (402) DTZS  
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 Grade 1: 10,000 cycles.  
4.3.4 Corrosion resistance (third digit)  
Padlocks and padlock fittings shall be classified in six grades.  
  
4.3.5 Security (fourth digit)  
Padlocks and padlock fittings shall be classified in security grades 1 to 6, where 6 is the highest.  
 
Example  
1 1 3 5 
 
Box 1 : Grade 1   
Box 2: Durability grade (1)   
Box 3: Corrosion grade (3)   
Box 4: Security grade (5 )  
 
4.4 Material  requirements  
4.4.1 The components of the various types of padlocks shall be manufactured from the recommended 
materials in Tables 3, 4, 5 and 6 and the manufacturer may select  suitable materials for the 
manufacture of padlock.  
Table 3 : Recommended Materials for Various Components of Padlocks (In General)  
S/No.  Component  Recommended  Material  
1 Key Brass sheet  or Steel sheet  or Stainless steel  or Nickel silver  
2 Spring  Spring steel wire  or Phosphor bronze wire  
3 Shackle  Bright bars  or Stainless steel  bars and flats or Stainless steel wire rod  
4 Case/Body  Steel sheet or Stainless steel sheet or Brass sheet  
 
Table 4 : Recommended Materials for Various Components of Disc Tumbler Padlock  
S/No.  Component  Recommended  Material  
1 Body and plug  Zinc base alloy Die castings or Aluminum alloy or Leaded brass or 
Nylon, delrin, Polycarbonate or Free cutting leaded brass  
2 Disc tumbler  Brass sheet or Steel sheet or Aluminum alloy  
 
 
Table 5 : Recommended Materials for Various Components of Pin Tumbler Padlock  
S/No.  Component  Recommended  Material  
1 Body and plug  Zinc base alloy  die castings or Aluminium alloy or Brass gravity die  
casting or Free cutting leaded brass  
2 Cylinder  Zinc base alloy die castings or Bras s gravity die casting or Brass rod  
3 Pin tumbler  Brass wire or N ickel silver rods  
 
   MEDC 02 (402) DTZS  
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 Table 6 : Recommended Materials for Various Components of Lever Padlock  
S/No.  Component  Recommended  Material  
1 Body and plug  Zinc base alloy die castings or Aluminium all ov or Leaded bra ss or 
Nylon, de lrin, polycarbonate,  etc or Brass sheet  
2 Lever  Brass sheet or  Steel sheet or  Alum inium alloy sheet  
3 Rivet  Mild steel wire  
 
4.4.2 Steel components shall be suitably protected to resist corrosion. The electroplated coating of 
nickel plus chromium, zinc on iron and steel or brass plating wherever specified, shall be done in 
accordance with Grade C of ISO 1456, Grade B of ISO 2081 and C lass A of ISO 19598 respectively. 
The electroplated coating of copper plus nickel plus chromium shall be done in accordance with ISO 
1456.  
 
4.5 Performance requirements  
4.5.1 Padlocks shall meet all t he required values set forth in Tables 7 -10 as applicabl e in orde r to 
qualify for the applicable grade level of 1 through 6.  
4.5.2 A failure of any one padlock in the forcing or cycle tests constitutes a failure of the c omplete 
test. See 5.3 for acceptance criteria for surreptitious entry tests.  
4.5.3 Successfully passing  the Salt Spray Test and Environmental Tests, or both, for any one model 
constitutes acceptance for  all sizes in the model tested, providing the materials used for all sizes are 
the same.  
4.5.4 Users may want padlocks exceeding the requ ired criteria of one or more of th e tests in a given 
grade level. Manufacturers may identify the grade level and leve ls of performance exceeding the 
requirements for that class (see Annex B ). 
4.5.5 Cylinder p icking, impressioning, rapping, decoding, and shackle shimming are d escribed in this 
specification. Since the skill of the  person doing the testing has a direct bearing on the resulting times 
of the tests, one of each test shall be conducted by a min imum of three different persons having 
experience of  not less th an three years of approximately the same skill level and the r esults averaged 
for determining relative levels of performance.  
4.5.6 Key bumping is a subjec tive test to be conducted using bump keys designed for the lo ck or 
cylinder being tested and an impact device as outlined in clause 6. 
4.5.7 Tolerances:  
4.5.7 .1 Fixture Tolerances —All tolerances shall follow standard machining practices unless otherwise 
specified.  
4.5.7.2 Test Set up Tolerances:  
4.5.7 .2.1 Force: 0.5 % of working range.  
4.5.7 .2.2 Height: 63 mm. 
4.5.7 .2.3 Torque: 4.0 % of reading.  
4.5.7.2.4  Weight: 610 g. 
4.5.8  Temperature —All tests  shall be conducted between 16° and 27°C (61° and 81°F).  
4.5.9  Test Reports —All test reports shall be dated.  
   MEDC 02 (402) DTZS  
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 Table 7: Cycle Tests Required Values  
Cycle Tests  Grades  
K1 K2 K3 K4 K5 K6 
Keyed Padlocks (× 1000)  1 10 25 50 75 100 
Force to Insert Key Maximum 
(all Grades) , N 12 N  
Force to Extract Key Maximum 
(all Grades) , N 12 N  
Torque to Rotate Cylinder Plug 
Maximum,  Nm 
(Newton Metres )  0.17 0.17 0.13 0.13 0.08 0.08 
Combination Padlocks (× 1000)  1 10 25 50 75 100 
 
Table 8: Required Values for Corrosion and Environmental Tests  
 Grades  
Corrosion Testing :  C1 C2 C3 C4 C5 C6 
Salt s pray cumulative time (h)  120 144 168 192 216 240 
Weathering Testing : W1  W2  W3  W4  W5  W6 
Salt spray (fog) cumulative time (h)  96  192  288  384  480  576 
UV light/ condensed moisture 
condensation cumulative time (h)  16 32 48 64 80 96 
UV light cumulative time (h)  32 64 96 128 160 192 
Exposure totals cumulative time (h) 144 288 432 576 720 864 
 
Table 9: Surreptitious Entry Tests Required Values  
Surreptitious Entry Tests  Grades  
1 (S1)  2 (S2)  3 (S3)  4 (S4)  5 (S5)  6 (S6)  
Picking or Manipulation, min  1⁄2 1 2 4 8 15 
Bump Key Attack, min  21⁄2 5 71⁄2 10 121⁄2 15 
Impressioning or Decoding min  N/A N/A 2 4 8 15 
Shackle Shimming Test min  1⁄2  1  2  4  8  15 
Drilling and Shimming min  N/A  N/A  N/A  4  8  15 
Rapping min  N/A  N/A  2  4  8  15 
 
Table 1 0: Forcing Tests Required Values  
Forcing Tests  Units  Grades  
1 (F1) 2 (F2)  3 (F3)  4 (F4)  5 (F5)  6 (F6)  
Tensile Force  newtons  1000  2500  5000  9000  20000 40000 
Shock /Impact  test 
blows   5 5 5 5 5 5 
Shock /Impact  test 
weights  kilograms  1  2  3  4  5  6 
Shock /Impact  test 
heights  meters  1 1 1 1 1 1 
Plug pull test  newtons  1000  1500  2000  3000  6000  12000 
Plug torque test  newton -
meters  10  15  20  25  30  35 
Shackle cutting  
force test  newtons  4450  9000  13500  18000  31000  45000 
Resistance to 
sawing of padlock 
body, shackle 
and staple  minutes  - - - 2 4 8   MEDC 02 (402) DTZS  
10 
 5 Test Methods  
5.1 Durability test /Cycle Test  
5.1.1 Keyed Padlocks:  
Prior to conducting the cycle test, insert key into each padlock cylinder 25 times and manually rotate 
both clockwise  and counter  clockwise (if possible , otherwise in the direction of opening) after each 
insertion.  
5.1.1.1 Operate the required  number of cycles at a rate not to exceed 10 cycles/min. Lubric ation shall 
not be added during the test.  
5.1.1.2 At the beginning  and the end of the cycle test, cylinders shall meet the operational  tests. The 
required value s for these tests are expressed in Table 7  of this specif ication . 
5.1.1.3 Failure occurs if th e test cannot be completed, the padlock does not operate at the conclusion 
of the test, the key breaks, or the requirements of 10.1.1.2 are not attained.  
5.1.2 Non -Key Retaining P adlocks  
In a test fixture which will horizontally hold the p adlock and mechanically operate the key, activate 
through a cycle consisting of the following:  
5.1.2.1 Fully inserting the key in the keyway.  
5.1.2.2 Rotating the key and cylinder plug the necessary number of degrees to open the padlock 
either clockwise or counter clockwise.  
5.1.2.3 Allowing the shackle to extend, if spring loaded, or not, moving the shackle to its full 
extension.  
5.1.2.4 Retracting the  key from the plug until the key tip no longer touches the front tumbler.  
5.1.2.5 Reengaging the shackle to the locked position.  
5.1.3 Key Retaining Padlocks  
In a test fixture that will hold the padlock horizontally and mechanically operate the key, activa te 
through a cycle consisting of the following:  
5.1.3.1 Fully inserting the key in the keyway.  
5.1.3.2 Rotating the key and plug the amount and direction necessary to open the padlock.  
5.1.3.3 Allowing the shackle to extend, if spring loaded, or if not, mo ving the shackle to its full 
extension.  
5.1.3.4 Reengaging the shackle to the locked position. Rotate key in plug to home position.  
5.1.3.5 Retracting the key from the plug until the key tip no longer touches the front tumbler.  
5.1.2 Combination Padlock  
Cycle single dial and multiple disk padlocks in alternate directions for the required number of cycles at 
a rate not to exceed 10 cycles per minute, with no more than a 2 s dwell. One cycle is equal to the 
number of revolutions necessary to upset all combi nation disks. At the conclusion of the test, failure 
occurs if the test cannot be completed or the padlock does not operate at the conclusion of the test. 
Lubrication shall not be added during the test.  
 
   MEDC 02 (402) DTZS  
11 
 5.2 Corrosion and Environmental Tests  
5.2.1 Corrosi on Resistant —Salt Spray Test  
After an exposure of the required number of hours  according to Table 8, padlocks shall operate. Test 
one padlock, suspended by nylon cord in the vertical upright position. Conduct the test and clean for 
10 min in accordance wit h ISO 9227 . Failure of any lock to unlock and relock within 1 min indicates 
failure.  
5.2.2 Weathering -Corrosion Environment Test  
Three padlocks are exposed to sequential cycles of salt spr ay and condensation -ultra violet radiation . 
At the conclusion of the  condensation -ultra violet radiation phase of the test, the padlocks are 
unlocked and relocked to check operation.  
The number of exposure hours for a specific grade is  shown in Table 8 . 
Failure of any lock to unlock and relock within 1 min indicates failur e. 
The padlocks must pass the previous grade level test successfully before being tested to the next 
grade level.  
5.3 Surrep titious Entry Tests (see Table 9 ) 
5.3.1  Picking or Manipulating Test  
5.3.1.1 Cylinders in padlocks sha ll resist picking (see 4.5.5 ) for the required time. Combinati on 
padlocks shall resist manual manipulation (see 4.5.5 ) for the required time.  
5.3.1.2 Cylinders or padlocks submitted for test containing pin tumblers shall be loaded using one 
each of the three or four mid -range bitting s available unless such a combination would not normally 
be supplied as a stock product. Cylinders in 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 padlocks submitted for testing, only a total of five samples of any size or sizes need to be 
tested.  
5.3.1.3 The tools used for this test shall be manual manipulating tools required by the operator, 
providing no visible marks are left detectable by the  unaided eye.  
5.3.2 Cylinder I mpressioning and Decoding Tests  
5.3.2.1 Cylinders shall resist successful impressioning and decoding (see 4.5.5 ) for the required time.  
5.3.2.2 Padlocks with cylinders submitted for test shall be loaded in accordance with 5.3.1.2. 
5.3.3 Shackle Shimming Test  
Insert any shim stock selected (see 4.5.5 ) 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 
required time.  
5.3.4 Cylinder Drilling and Shimming Test  
5.3.4.1 Use hand -held tools.  
5.3.4.2 Load cylinders in accordance with 5.3.1.2 . 
5.3.4.3 Cylinders in locked padlocks hanging from a hasp shall resist drilling and shimming for the 
required time. Results of the drilling te st shall not be obvious to the unaided eye.  
5.3.5 Rap Test  
5.3.5.1 Use hand -held tools.    MEDC 02 (402) DTZS  
12 
 5.3.5.2 Padlocks shall resist successful rapping on the cylinder and case (see 4.5.5 ) for the required 
time.  
5.3.6 Key Bumping Test —The testing person must change the o rder of testing for 5.3.6.1 and 5.3.6.2 
to use the most likely successful bumping attack first.  
5.3.6.1 A lock or cylinder not previously bump tested by the locksmith is permitted to be mounted in a 
block if the testing person prefers that method and have the prepared pull bump key inserted. A 
prepared pull bump key is permitted to have a hole drilled in the bow for mounting a weight bar.  
5.3.6.2 A lock or cylinder bump tested per 5.3.6.1 is permitted to be mounted in a block if the testing 
person prefers t hat method and have the prepared push bump key inserted. A prepared push bump 
key is permitted to have a hole drilled in the bow for mounting a weight bar.  
5.3.6.3 Impacts with the impact device shall be by hand using a rapping motion which ensures that 
the impact device applies force to the bump key a single time and does not allow bouncing impact of 
the impact device.  
5.3.6.4 Impacts to the key shall be performed at a minimum rate of 4 per minute. Any accelerated rate 
of impact is permitted to be used during the test to achieve the quantity of impacts required by the 
stated minimum rate/time requirement for a given grade level, that is, 10 impacts in 2.5 min by each 
type of bump key without operation = Grade 1, or 10 impacts by each type of bump key in less than 
2.5 min without operation = Grade 1.  
5.3.6.5 The torque applied to the bump key during the impact testing shall be no less or no greater 
than the testing person has found optimum from past experience.  
5.3.6.6 If the cylinder or lock is not operat ed by the bump key within 10 impact cycles of either type of 
bump key, the lock is classed as Grade 1. Locks or cylinders that are operated by either type of bump 
key in 10 or less impacts will be qualified as having Grade zero bump resistance.  
5.3.6.7 The  test described in 5.3.6.4  – 5.3.6.6 shall be repeated through 10 complete impact cycles 
with each type bump key for each Grade level from 2 through 6 or until operated by a bump key. A 
cylinder or lock that is operated by either type of bump key on the 11 th through 20th cycle will be 
qualified as Grade 1, 21st through 30th = Grade 2, 31st through 40th = Grade 3, 41st through 50th = 
Grade 4, 51st through 60th = Grade 5. Any cylinder or lock that resists operating for a total of 60 
impacts by each type of bu mp key shall be qualified as Grade 6.  
5.3.6.8 The test shall be repeated for each of the remaining cylinders.  
5.3.6.9 At the conclusion of testing by each locksmith the seventh cut key shall be used to verify that 
the lock or cylinder still functions.  
5.3.6.10 Failure of the lock or cylinder to function does not constitute failure of the testing since it 
provides a detection method of a bumping attempt.  
5.3.6.11 A lock or cylinder which captures the bump key to prevent an unlocking motion using a bump 
key shall be classed as Grade 6.  
5.4 Forcing Tests (see Table 1 0) 
5.4.1 Tensile Test (Does not app ly if test cannot be performed) (see 6.1) 
Support the lock ed padlock in a fixture bearing against the top surface of the ca se without interfering 
with the shackle or giving support thr ough the top of the case to the shackle retaining mechanism. 
Apply the required force slowly along the vertical centerline of th e padlock in a direct and equal 
tension on each leg of the shackle . Failure occurs if the padlock  opens.  
5.4.2 Shock Test  
Using the  impactor ( 6.2) drop the weight the required number of times o n the top of the locked 
padlock case. Failure occurs if the padlock opens.    MEDC 02 (402) DTZS  
13 
 5.4.3 Plug Pulling Test  
Drill the  keyway with a No. 20 , 4 mm  (0.161 in.) diameter drill  and i nsert a Type AB No. 12 screw at 
least 19 mm (0.75 in.) deep. A pply the required tension ( 6.1) axially between the case and the 
installed screw. Failure occurs if the cylinder plug or cylinder assembly c ompletely separates from the 
case, or if the pad lock can be opened by manipulation with a screwdriver at the conclusion of the test.  
NOTE 1: Some cylinders are of a conf iguration such that a different attachment may be needed in 
order to apply the required loads.  
5.4.4 Plug Torque Test  
5.4.4.1 Install the padlock in a rigid fixture such as a vice to support it firmly but not restrict f ree 
rotation of the plug in the cylinder.  
5.4.4.2 Insert a blade type tool into the keyway, so that a torque load can be applied to the plug. 
Failure occurs if t he padlock opens.  
5.4.5 Shackle Cutting Test (D oes not apply if test cannot be performed)  
Shackles shall w ithstand cutting through when 2 shearing blades made o f a steel hardened to a 
minimum hardness of Rc 50, are use d in conjunction with the blade positi oning holder, is placed in a 
tensile loading device ( 6.1) having a compression load cap ability and compressed with the required 
force. See Annex B  for details. Failure occurs if the shackle is cut through.  
5.4.6 Sawing Test  
Mount the padlock  on to a suitable test rig for use with a sawing machine as shown in Fig. B.10. Saw 
blades used shall be bi -metal saw blades with 24 TPI tensioned to 1 kN. The sawing machine shall 
make 60 complete 165 mm stroke cycles per minute, with an applied load of 9 0N. Do not use any 
coolant during the test.  Sawing shall be carried out for vulnerable areas fo time t (Table 10).  
 
6. Preparation of Apparatus  
6.1 Tensile Loading Device  
Provide a tensile loading device having a load and force  measuring capacity of 44 500 N (10000lbf). 
6.2 Shock Impactor:  
6.2.1 Provide a fixture as ill ustrated in Annex B  which allows the weights described in (6.2.2) to be 
properly guided to strike the anvil rod which will be placed in direct c ontact with the top surface of a 
padlock using the mounting block described in (6.2.3).  
6.2.2 Make a set of weights as shown in Annex B , with a  central hole in each that allows t he weight 
selected to free fall and strike the top surface of the anvil rod.  
6.2.3 Make a mounting block that will support the specimen on the mounting block when being 
subjected to the required shock load (see Table 1 0). 
6.3 Key Bumping:  
6.3.1 Each locksmith performing the test shall use two of the supplied keys to fabricate his ow n pull 
bump key and push bump key.  
6.3.2 Both a pull bump key and a push bump key shall be used to test a lock or cylinder for bump 
resistance by each of three locksmiths.  
6.3.2.1 A torque bar is permitted to be used if the test person prefers that method.    MEDC 02 (402) DTZS  
14 
 6.3.2.2 A single impact cycle consists of having a bump key fully inserted into the keyway and 
withdrawing it one cut position for the pull type, inserting the key fully into the keyway and then 
releasing it to allow the pins to center it for the push typ e, impacting the end of the key to drive it fully 
into the keyway while torque is applied. If the cylinder or lock operates after the impact, it failed the 
test at that cycle and shall be given the appropriate grade level for the last cycle that did not 
accomplish operation. If it did not operate, a new cycle shall be achieved until the lock or cylinder 
reaches Grade 6.  
6.3.3 Provide various mounting blocks for locks or cylinders as required by the test person if rigid 
mounting is preferred.  
6.3.4 The impac t device shall be a non -metal instrument with a weight not to exceed 0.25 lb (113.4g).  
 
7 Sampling  and Inspection  
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.  
The number of sample locks to be selected at ran dom from a lot shall depend upon the size of the lot  
and shall be in accordance with Table 11 . The padlocks in the samples shall be selected at random 
from the lot.  
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 shall be taken from each box so as to constitute the required 
sample size.  
The padlocks selected shall be inspected for dimensions, workmanship and finish. The lot shall be 
considered as conforming to these req uirements 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 11 . 
 
Table 11 : Sample Size and Criteria for Conformity  
S/No.  Lot Size (No. of  
Locks in the Lot)  Dimensions, Workmanship and 
Finish  Material and Performance  Test 
Sample Size  Permissible No. of  
Defective 
Padlocks  Sub-sample  Permissible No. 
of 
Defective 
Padlocks  
1 Up to 50  8 0 2 0 
2 51 to 150  13 0 2 0 
3 151 to 300  20 0 2 0 
4 301 to 500  32 1 3 0 
5 501 to 1000  50 2 5 0 
6 1001 to 3000  80 3 10 0 
7 3001 to 10000  125 5 15 1 
8 10001 and above  200 7 20 2 
 
 
 
   MEDC 02 (402) DTZS  
15 
 8 Packaging  and Marking  
7.1 Each padlock with its keys shall be packed in a  moisture proof paper or polyethylene bag, or as 
agreed  to between the purchaser and the supplier.  
 
7.2 Each package of padlocks shall be marked with the following information:  
 
a) manufacturer's name or initials or trademark;  
b) batch number;  
c) classification and size  of the padlock;  
d) country of origin;  
 
7.3 Each padlock shall be marked with the following information:  
a) manufacturer's name or initials or trademark;  
b) batch number;  
c) classification and size  of the padlock;  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   MEDC 02 (402) DTZS  
16 
 ANNEX  A 
(Informative)  
SHAPE  
A1.1 Padlock Shape  
A1.1.1 The typical shape and design of padlocks and their designs may also be made as per 
manufacturer’s patent  illustrative and for guidance only. Other shapes and  designs may also be made 
as per manufacturer ’s patent  or as agreed to between the purchaser and the supplier.  
 
Figure  1: Disc Tumbler Padlock  
 
 
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Figure 2: Lever Padlock  
 
 
 
 
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Figure 3 : Pin Tumbler Padlock  
 
 
 
 
 
 
 
  MEDC 02 (402) DTZS  
19 
 ANNEX B  
(Informa tive) 
USER GUIDE  
B1.1 Padlock Class Rating  
B1.1.1 Padlocks meeting all the requirements of one of the  Grades 1 through 6 shall be so rated.  
B1.1.2 A padlock complying with one of the grades may  exceed the requirements for that grade in the 
surreptitious entry  test category or the forcing test category.  
B1.1.3 A rating beyond 1 through 6 may be used by some  manufacturers. For example, a padlock 
designated as Grade 3  may also have the parenthetical designation (F5S3). This  would mean the 
padlock met the requirements for forcing test  of Grade 5. Users of padlocks not overly concerned with  
surreptitious entry attack but wanting relatively high resis tance  to forcing would find such a padlock 
more useful than one  rated Grade 3.  
B1.1.4 The environmental tests listed in Table 4 are optional  tests to be specified as needed by users 
of this standard. Taking  into account the manner of padlock class rating a s explained in  
B1.1.1 – B1.1.3, combining requirements of forcing tests, surreptitious entry tests and environmental 
tests  in varying  grade levels for each category can result in specifying padlocks  that do not exist. If the 
product desired is not readily related to  a known padlock, ind ividual manufacturers should be 
consulted.  
B1.2 Options  
B1.2.1 Under the function description, several optional  features are described, including one for 
corrosion resistant  criteria for padlocks used in an exterior or corrosive  environment, one for 
nonferrous shackles used in situations  where it is desirable for the shackle to be easily severed, one  
for those wishing a removable core feature, and others.  
B1.2.2 These should be specified by indicating the function  requir ed with optional feature(s) desired.  
B1.3 Chains  
B1.3.1 If chains attached to the padlock are required, they  must be so specified.  
B1.4 Keys  
B1.4.1 Two keys are customarily furnished with each padlock.  If more or less are required, they must 
be so specifie d. 
B1.5 Hasps  
B1.5.1 Hasps are not addressed in this standard. The  strength and fastening system of a hasp must 
be compatible  with the grade of padlock in order to maintain the integrity of  the locking system.  
B1.6 Sizes  
B1.6.1 Padlocks are generally sized  according to the width  of the case. As this width increases, the 
diameter of the shackle  and the vertical and horizontal clearance between the shackle  and the case 
increases. As the diameter of the shackle gets  larger, its resistance to cutting attack bec ause of 
greater mass  becomes higher. Consequently, the same series of padlocks  may have a low grade 
rating in a small size and an increasingly  higher rating in subsequently larger sizes.  
B1.7 Safe Key or Combination Changes  
B1.7.1 Safe key or combination c hanges (those that do not  interchange) are not unlimited and vary 
according to the  number of tumblers in a cylinder or a combination mechanism.  While this is not a 
function of the security of a single lock  under this Standard, it becomes important in a sys tem   MEDC 02 (402) DTZS  
20 
 incorporating  many locks which have different keys or combinations  for each lock. Anyone using this 
standard for procurement  purposes must specify the number of safe changes required.  
B1.7.2 Unless unique methods are used which are generally  proprietar y, any simple 6 pin master 
keyed system is limited to  approximately 4000 safe key changes. If a relatively high  security system is 
wanted and the system is still to be master  keyed, safe changes are reduced to about 1000. If a 4 or 5 
pin tumbler system is used, the safe key changes are again  substantially reduced.  
B1.7.3 No master key at all is best for achieving the goal of  higher security, but may be inappropriate 
for efficient administration  of the system.  
B1.7.4 If  requirements appear to be complex, individual  specialists or manufacturers should be 
consulted.  
B1.8 Tests  
B1.8.1 The forcing tests  included in this standard were devised so as to be accurat ely repeatable in a 
laboratory environment. The nature of t he for ces and loads imposed are intended to encourage the 
production of a padlock which will withstand a balanced variety o f attacks. Criteria selected is based 
on guarding agains t known attack methods employed with the greatest frequency. User s of this 
standard  with special needs may wish to impose additional cutting or forcing tests.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   MEDC 02 (402) DTZS  
21 
 ANNEX B  
(Norma tive) 
Test Rig Illustrations  
 
Figure B.1:  Cylinder plug or locking mechanism torque test  
 
 
Figure B.2: Cylinder locking mechanism Actual Pull Test 
 
Figure B.3: Shackle/Staple Pulling Test  
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Figure B. 4: Shackle/ Staple Twisting Test  
 
 
 
 
 
 
 
 
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Figure B. 5: Shackle/ Staple Cutting Test  
 
 
 
Figure B. 6: Impact Test on Padlock Body  
 
 
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Figure B. 7: Impact Test on Padlock Shackle  
 
 
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Figure B. 8: Impact test on Staple  
 
 
 
 
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26 
  
Figure B.9: Drilling Test  
 
 
Figure B. 10: Sawing  Test 
 
  MEDC 02 (402) DTZS  
27 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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