MEDC 02 (400) DTZS  
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DRAFT TANZANIA STANDARD  
 
 
 
Door Locks and Latches  – Specification  
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
              TANZANIA BUREAU OF STANDARDS  
 
 
© TBS 2 021                                                                                                    First  Edition 20 21 
  MEDC 02 (400) DTZS  
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 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established under the Standards Act No. 3 of 1975, repealed and replaced by the Standards Act No. 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 Automotive 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 (400) DTZS  
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 Door Locks and Latches – Specification  
0  Foreword  
Door Locks and Latches  are locks  used  in door furniture  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 door locks and l atches  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 Standard TZS XXXX : 2021 , Door 
Locks and  Latches – Specification . 
 
This Tanzania Standard has been prepared by the Metals and Structures Technical Committee under 
the supervision of the Mechanical Engineering Divisional Standards Committee.  
 
For the purpose of deciding whether a particular requi rement 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:  
 
SANS 4:2008 , Locks, la tches, and associated furniture for doors (Domestic Type) , 
published by South African Bureau of Standards (SABS ). 
  
1 Scope  
This Tanzania Standard  specifies requirements, test methods and sampling of  mortice  locks and 
latches , rim locks and latches , and the associated lock and latch furniture . It covers the requirements 
for the materials, es sential dimensions, finish, and performance for mortice locks and latches, rim 
locks and latches, an d the associated loc k and latch furniture.  
 
2 Normative references  
This Tanzania Standard incorporates by dated or undated reference, provisions from 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 Standard only when incorporated in it by amendment or 
revision. For undated references the latest edition of the publication referre d to applies (including 
amendments).  
ISO 3575 , Continuous hot -dip zinc -coated carbon steel sheet of commercial and drawing qualities . 
ISO 1458 , Metallic coatings – Electroplated coatings of nickel.  
ISO 1456 , Metallic  and other inorganic coatings — Electrodepos ited coatings of nickel, nickel plus 
chromium, copper plus nickel and of copper plus nickel plus chromium  
ISO 301, Zinc alloy ingots intended for castings . 
ISO 2081 , Metallic and other inorganic coatings — Electroplated coatings of zinc with supplementary 
treatments on iron or steel . 
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests  
 
   MEDC 02 (400) DTZS  
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 3 Terms and Definitions  
For the purpose of this standard the fo llowing definitions shall apply:  
3.1 cylinder assembly  
a separate key -operated unit, of the pin -tumbler type, that is fitted to and operated in conjunction with  
the locking mechanism of a lock/latch  
3.2 cylinder mortice lock  
a mortice lock for fitting into a mortice cut into the locking edge of a door, and oper ated by a single - or 
double -sided cylinder mechanism. (Single -sided versions may, when relevant, have a thumb turn or  
knob fitted to the non -keyed side of the lock.)  
3.3 cylinder rim night latch  
a latch for mounting on the inner face of a door and operated  from the outside of the door by a 
cylinder  assembly and from the inside by an integral knob or thumb turn or cylinder assembly. (A rim 
latch may  have a secondary button or lever that enables the spring bolt to be retained in either the 
open or the  locked position.)  
3.4 deadlock  
a lock in which a dead -bolt mechanism is both opened and locked by means of a key, there being no  
spring action involved in the movement of the dead bolt. (See " Mortice bathroom/toilet lock ".) 
3.5 defective  
a unit that fails, in one or more respects, to comply with the relevant requirements of the  specification  
3.6 follower  
a spindle -operated device that operates a spring -bolt mechanism or a bathroom/toilet lock dead -bolt 
mechanism  
3.7 fore-end 
a) single  
a pla te permanently attached to the front of a lock/ latch, and through which the bolt(s) operate  
b) double  
two plates, one permanently attached to the front of a lock/latch and the other superimposed on  the 
first plate and attached by screws to the front of a lock,/latch. The bolt(s) operate through both  plates  
3.8 furniture  
a generic term for all or any of the following items supplied separately, in sets, or as part of a  
lock/latch set: Lever handles, knobs, escutcheons, spindles, screws, and any other ancillary  
components  
3.9 latch  
a spring -loaded bolt mechanism (in a case) operated from one or both sides by a lever handle, knob,  
thumb turn, key, cylinder mechanism, or any combination of these devices  
3.10 lever handle  
a lever in the form of handle runn ing in a rose or plate, and that operates a spring -bolt mechanism by  
means of a spindle  
   MEDC 02 (400) DTZS  
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 3.11 lot 
not less than 10 and not more than 1 200 units, of the same size, type, and finishes, from one  
manufacturer, and submitted at any one time for inspection and testing  
3.12 mortice bathroom/toilet lock  
a lock for fitting into a mortice cut into the locking edge of a door and having a spring -bolt mechanism 
operated from both sides by lever handles and a dead -bolt mechanism operated by a  knob or thumb 
turn from the inner side only. (Provision is often made for a cipher or colour -coded  "engaged" indicator 
that is operated when the dead bolt is locked.)  
3.13 mortice deadlock  
a deadlock for fitting into a mortice cut into the locking edge of a door  
3.14 mortice latch  
a latch for fitting into a mortice cut into the locking edge of a door  
3.15 mortice lock  
a lock for fitting into a mortice cut into the locking edge of a door and having both a spring -bolt 
mechanism and a key -operated dead -bolt me chanism  
3.16 paracentric  
descriptive of the section of the keyhole of a cylinder lock mechanism that is such that it does not  
admit a flat strip of metal. (It is also descriptive of the section of the corresponding key blade)  
3.17 rim lock  
a lock for fitting to the inner face of a door and having a spring -bolt mechanism and a key -operated  
dead -bolt mechanism  
3.18 staple  
a metal box for fitting to the inner face of a door frame and having an opening or openings in which 
the bolt(s) of a rim lo ck/latch engage when a door is in the closed position  
3.19 striking plate  
a plate for fitting to the locking edge of a door frame and having an opening or openings in which the  
bolt(s) of a mortice lock/latch engage  
3.20 unit 
a lock or a latch, or a lock s et, a latch set, or a furniture set ( see 4 .1.2) 
3.21 m ortice night l atches  
Any mortice l ock having a single spring bolt withdrawn f rom the outside by key and from inside by a  
handle and with an arrangement whereby the lo ck can be prevented from being opened by its k ey 
from outside while the night latch is used inside the room.  
 
4 Requirements  
4.1 Type and sets  
4.1.1 Lock and latch types  
Locks and latches shall be of one of the following types and shall be right - or left -handed, as specified    MEDC 02 (400) DTZS  
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 (in both cases) by the purchaser:  
a) cylinder mortice lock (single - or double -cylinder);  
b) cylinder rim night latch;  
c) mortice bathroom/toilet lock;  
d) mortice deadlock;  
e) mortice lock;  
f) mortice latch;  
g) rim lock;  
h) rim latch.  
4.1.2 Sets  
A lock set, la tch set, or furniture set shall be of one of the following types, as specified by the  
purchaser:  
a) A lock set. A lock of the relevant type (see 4 .1.1) complete with all appropriate furniture and, when  
relevant, a key or keys.  
b) A latch set . A latch of the relevant type (see 4 .1.1) complete with all appropriate furniture and,  
when relevant, a key or keys.  
c) Furniture set . Furniture appropriate to the re levant type of lock/latch (see 4 .1.1) and for both  sides 
of a door, with spindle and appropriate screw s. 
4.1.3 Design and finish  
The design of furniture and the decorative finishes on fore -ends and cylinder assemblies shall be as  
specified by the purchaser.  The method of manufacturing of locks , latches  and its components is left 
to the manufacturer; however, it shall meet the requirements laid down in this standard. All 
components of the locks, latches and keys shall be finished smooth to minimize frictional resistance in 
their working.  
The body of the locks/latches, if required, shall be suitably painted/plated. Steel components shall be 
suitably protected to resist corrosion.  
4.1.4 Lock differs  
a) Lever locks/latches . Lever type mortice locks/latches shall have at least the appropriate of the  
following  number of different arrangements of levers or key sections (bullet warding) or both:  
Number  of levers or key sections or both in lock/latch  No. of differs, min.  
2 12 
3 36 
4 48 
5 250 
NOTE:  In no case shall it be possible to unlock a lock/latch with a key of another differ, and in no case shall  
any differ be repeate d in another lever arrangement.  
 
b) Pin-tumbler cylinder mechanisms . There shall be at least 5 pins (not including driver pins)  in a 
pin-tumbler cylinder mechanism. The pins shall be available in at least 5 different lengths and  the 
differing system shall be capable of using all available lengths. The difference between any  2 leng ths 
of pins shall be at least 0. 39 mm, and the pins  in an individual cylinder mechanism shall  be of at least 
2 different lengths.  
4.2 Materials    MEDC 02 (400) DTZS  
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 4.2.1 Zinc base alloys  
Zinc base alloys used in the manufacture of locks, latches, and lock and latch furniture shall comply  
with the requirements of  ISO 301 . 
4.2.2 Other materials  
Other materials used in manufacturing shall be such that units and components made of these  
materials pass the relevant tests given in section 6 . 
4.3 Dimensions  
4.3.1 General dimensions  
The general dimensions of the different types of locks and latches shall be as shown in the relevant of  
figures 1 -4. Locks and latches having sizes other than those specified in figures 1 -4 may also be 
permitted as agreed to between the purchaser and the supplier.  
 
Figure 1 — 80 mm Mortice lock, mortice  latch, mortice  deadlock, and mortice bathroom/toilet 
lock 
NOTE : 
  MEDC 02 (400) DTZS  
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 a) These illustrations are for purpose of giving certain essential dimensions and are not intended to 
show  design details.  
b) The overall length and width of the fore -end shall be as specified by the purchaser, the value in 
each case  being one of those given above.  
 
 
Figure 2 — Double cylinder mortice lock  
NOTE : 
a) These illustrations are for purpose of giving certain essential dimensions and are not intended to 
show  design details.  
b) The overall length and width of the fore -end shall be as specified by the purchaser, the value in 
each case  being one of those given above.  
 
  MEDC 02 (400) DTZS  
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Figure 2(a) — Mortice lock (Tubular type)  
NOTE : This illustration is for purpose of giving certain essential dimensions and is not intended to 
show  design details.  
 
 
Figure 3 — Cylinder rim night latch  
  MEDC 02 (400) DTZS  
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 NOTE : These illustrations are for the purpose of giving certain e ssential dimensions and are not 
intended to show design details.  
 
 
Figure 4 — Horizontal two -bolt rim lock  
NOTE : This illustration is for purpose of giving certain essential dimensions and is not intended to 
show  design details.  
 
 
Figure 5 — Rotating cam  
 
 
 
  MEDC 02 (400) DTZS  
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 4.3.2 Rebated fore -end 
The depth of the rebate of a rebate d fore -end shall be at least 12. 5 mm.  
4.3.3 Throw of bolts  
The throw of a bolt shall be  
a) in the case of a dead bolt and a spring bolt other than a spring bolt for a tubular mortice latch, at  
least 10 mm; and  
b) in the case of a spring bolt for a tubular mortice latch (see figure 2(a)), at least 8 mm.  
4.3.4 Spindle  
A spindle shall be of 8 mm square cross -section, with a tolerance of  +0
−0.5 𝑚𝑚. 
4.4 Construction  
4.4.1 Keys  
Keys shall be of the appropriate of the following types, and the number to be supplied with each  
lock/latch shall be as specified by the purchaser:  
a) Cylinder type keys . Cylinder type keys shall consist of a paracentric blade with cuts in the edge  
that operate the pins of a cylinder assembly and, at the other end of the blade, a bow for turning  the 
key. 
b) Lever type keys . Lever type keys shall consist of a round shank with, when relevant (see 4.4.2 ), a 
collar, and having on one end a bit containing steps to operate the locking mechanism of a  lock/latch 
and, at the other end, a bow for turning the key.  
4.4.2 Keystop and key collar  
When necessary in a double -sided lock/latch, a suitable keystop in the lock/latch or a collar on the  key 
shall be provided to prevent the key bit from being pushed through both keyholes from one  side.  
4.4.3 Latch spring action  
In a mortice lock/latch the spring -bolt mechanism shall have one of the following actions, as  specified 
by the purchaser:  
a) Plain action , i.e. a latch mechanism so sprung as to be suitable for use with kno bs or spring  
loaded  lever handles.  
b) Easy action , i.e. a latch mechanism suited for use with unsprung lever handles and so sprung  as 
to permit easy closing of a door to which it is fitted, but having additional spring -loading so  arranged 
as to ensure the return of the spring bolt follower to the original position after the handle  is released.  
4.4.4 Striking plate  
Striking plates shall be one of the following, as specified by the purchaser:  
a) Plain , i.e. a plate having suitable apertures to accept the bolt (s) of a mortice lock/latch and  having 
holes for fixing screws.  
b) Box, i.e. a similar plate to (a), but having an additional box -like structure fitted to the rear face to  
strengthen the plate and protect the bolt(s) of a mortice lock/latch.  
4.4.5 Bathroom /toilet lock  
Mortice bathroom/toilet locks shall be fitted with means for opening from the outside in an  emergency.  
   MEDC 02 (400) DTZS  
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 4.5 Performance requirements  
4.5.1 General requirement  
When submitted to the relevant tests given in 6.2.2  - 6.2.8 (inclusive) locks, latches, and components  
of lock sets, latch sets, and furniture sets shall not jam or break, and, after testing, shall still be  
capable of correctly performing the functions related to the test conducted.  
4.5.2 Durability of lever handles  
When tested in ac cordance with 6.2.5 , a lever handle and its plate or rose shall, on completion of the  
test, be intact and shall operate the spring -bolt mechanism without undue difficulty. Minor sagging of 
the lever handle shall be permitted provided that the correct opera tion of the spring -bolt mechanism is  
not affected.  
4.5.3 Accuracy of follower  
When a lock/latch is tested in accordance with 6.2.9 , the follower shall be capable of being turned  (in 
both directions, if the design allows) sufficiently to withdraw the latch bolt completely. On release of  
the follower, the latch bolt shall be returned to its original position by its own spring pressure.  
4.5.4 Strength of spring -bolt spring  
The force required to depress a spring bolt to within 1 mm of the fore -end, determined i n accordance 
with 6.2.10 , and shall  be 11.5 ± 2. 5 N. 
4.5.5 Security of dead bolt  
When the dead bolt of a lock is tested in accordance with 6.2.11 , 
a) it shall be possible, by turning the key, to throw out the dead bolt to the locked position while it  
supports the test load;  
b) there shall be no tendency for the dead bolt to drop back into the withdrawn position while the  key 
remains in the locked position; and  
c) it shall be possible to withdraw the bolt to the unlocked position while it still supports  the test  load.  
4.6 Finish  
4.6.1 General  
With the exception of springs, all components not made from inherently corrosion -resistant material  
from corrosion by an acceptable coating that complies with relevant requirements of 4.6.2 or 4.6.3. 
4.6.2 Plated co atings  
a) Zinc plating . The thickness of an electroplated coating of zinc on a lock - or latch -case or an  inner 
component shall comply with the requirement of ISO 2081 . 
b) Nickel plating . The adhesion of a nickel -plated coating on a component made of iron or steel  shall 
comply with the adhesion requirement of ISO 1458  and its thickness shall comply, in the  case of keys, 
with the requirement for application grade LOW and, in the cases of other components, with the 
requirement for application grade MEDIUM of table 1 of ISO 1458 . 
c) Chromium on nickel plating . The adhesion of a combined chromium -plated coating and a  nickel -
plated base coating on an exposed component shall comply with the adhesion  requirement of ISO 
1456 , and the thickness of the component coatings shall comply with the  relevant requirements of 
ISO 1456  for Service condition 3 (severe), subject in the case of nickel  and (when relevant) copper to 
a tolerance of −20 %.  
d) Hot-dip galvanizing . A coating that is applied by means of for hot -dip galvanizing shall comply  
with the requirements for a coating of class of ISO 3575 .    MEDC 02 (400) DTZS  
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 4.6.3 Paint coatings  
When subjected, in accordance with 6.2.13 , for a period of 24 h, to a salt spray, a paint coating shall  
show no blistering, wrinkling, or loss of adhesion and there shall be no sign of corrosion of the base  
metal.  
 
5 Sampling and compliance with the specification  
5.1 Sampling  
The following sampling procedure shall be applied in determining whether a lot submitted for  
inspection and testing complies with the relevant requirements of the specification. The samples so  
taken shall be deemed to represent the lot for the respective properties.  
5.1.1 Sample for inspection  
From the lot take at random the number of units given in column 2 of table 1 relative to the  
appropriate lot size given in column 1.  
5.1.2 Sample for testing  
From the lot or, after inspection (see 6.1), from the sample taken in accordance with 5.1.1 take at  
random the number of units given in column 4 of table 1 relative to the appropriate lot size given in  
column 1.  
Table 1 — Sample sizes  
Size of lot  
units  Sample for inspection  Sample for testing  
units  Sample size  
units  Acceptance number  
defectives  
10 – 25 3 0 2 
26 – 90 5 0 2 
91 – 150 8 0 4 
151 – 280 13 1 4 
281 – 500 20 2 6 
501 – 1200  32 3 8 
 
5.2 Compliance with the specification  
The lot shall be deemed to comply with the requirements of the specification if  
a) after inspection of the sample taken in accordance with 5.1.1 , the number of defectives found  does 
not exceed the relevant acceptance number shown in column 3 of table 1; and  
b) after testing of the sample taken in accordance with 5.1.2 , no defective is found.  
 
6 Inspection and test methods  
6.1 Inspection  
Visually examine and, where relevant, measure each unit in the sample taken in accordance  with 
5.1.1 for compliance with the requirements of section 7  and the other requirements of the  specification 
compliance with which is not assessed by tests given in 6.2.2 - 6.2.13.  
 
 
   MEDC 02 (400) DTZS  
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 6.2 Methods of test  
6.2.1 Test conditions and  mounting of units for testing  
Test each unit in the sample taken in accordance with 5.1.2 in the "as received" condition and fully  
assembled. Do not dismantle, lubricate, or otherwise precondition the mechanism before testing a  
unit. Firmly mount a lock/latch (with, when relevant, its associated furniture) in a jig so designed as  to 
ensure accurate alignment of the various components of a lock/latch set with each other. If the  units in 
the lot are locks or latches, any suitable f urniture or device for operating the units may be  used to 
facilitate testing.  If the units in the lot are furniture sets, use, for testing the units, any lock/latch of the 
type for which  the furniture sets are intended.  
6.2.2 Strength of latch mechanism  
Mount the lock/latch under test as described in 6.2.1 (but without furniture). Insert a follower spindle  
into the follower, apply a torque of 10 N ·m to the spindle for a period of 30 s, and then check for  
compliance with 4.5.1. 
6.2.3 Dead -bolt mechanism dura bility test  
Mount the lock under test as described in 6.2.1 with the fore -end vertical and the key (when  
applicable) inserted in the lock. Position the bow of the key in a loose -fitting chuck which is so  
arranged that, when turned, only a pure torque is ap plied to the key. By turning, in the case of a  
bathroom/toilet lock, the thumb turn/knob through an angle sufficient to fully extend the dead bolt,  and 
in other cases by turning the key through an angle of not less than 180° and not more than  360°, and 
then returning the thumb turn/knob or the key through the same angle, operate the  deadlock 
mechanism for 30 000 cycles at a rate of 60 ± 5 cycles per minute.  
NOTE: Throwing the bolt fully out to the extended position and then fully withdrawing it constitutes a 
complete  cycle.  
If, in the case of a mortice lock or a rim lock, either the deadlock mechanism or key or, in the case  of 
a cylinder mortice or bathroom lock, the deadlock mechanism, fails during the test, consider the  unit 
to be a defective. On completio n of the test check for compliance with 4.5.1. 
6.2.4 Cylinder assembly durability test  
Mount the cylinder mortice lock/cylinder rim night latch under test as described in 6.2.1 with the  fore-
end vertical. Conduct the test as follows:  
a) Cylinder mortice lo cks. Insert the key into the cylinder to operate the deadlock mechanism and,  
by turning the key, throw the dead bolt into the locked position and then into the unlocked  position and 
withdraw the key, thus completing one cycle.  
b) Cylinder rim night latches . Insert the key into the cylinder to operate the latch, so turn the key  as 
to withdraw the latch bolt to within 1 mm of the fore -end, release the key (and thus the latch  bolt), and 
withdraw the key, thus completing one cycle. Carry out test (a) or (b) abo ve (as  relevant) for a total of 
30 000 cycles at a rate of 60 ± 5 cycles per minute, and if, during the test,  either the key or the 
cylinder mechanism fails, consider the unit to be a defective. On completion  of the appropriate test, 
check the lock/latch f or compliance with 4.5.1. 
NOTE : Test (a) may be conducted in conjunction with the test on cylinder mortice locks given in 6.2.3.  
6.2.5 Durability test for spring -bolt mechanisms, knobs and lever handles  
Mount the unit as described in 6.2.1 with the fore-end of the lock/latch vertical. Using a suitable  
mechanism, so operate (by applying a pure torque only) the lever handle or knob that the latch  
follower withdraws the spring bolt to within 1 mm of the fore -end and then releases it, allowing the  
spring  bolt to return completely to the rest position. Repeat this sequence of operations for  100 000 
cycles at a rate of 60 ± 5 cycles per minute.    MEDC 02 (400) DTZS  
15 
 Then if the unit under test is : 
a) a lock/latch or a lock/latch set, check the lock/latch for compliance with 4.5.1; 
b) or a lock set, a latch set, or a furniture set, check the knob or lever handle and its plate or rose  for 
compliance with 4.5.2. 
6.2.6 Durability test for latch mechanisms  
Mount the lock/latch under test as described in 6.2.1 with the fore -end vertica l. By means of a  suitable 
rotating cam (see figure 5), depress the spring bolt to within 1 mm of the fore -end and then  release it, 
allowing the spring bolt to return completely to the rest position (thus completing one  cycle). Repeat 
this sequence of operations for 100 000 cycles at a rate of 60 ± 5 cycles per minute,  and then check 
for compliance with 4.5.1. 
6.2.7 Strength of lockcase and bolts  
Mount the lock/latch under test as described in 6.2.1. Apply without shock, and as follows, a static  
force of 1 600 N to the bolt(s) in the unit under test: Using a steel bearer having a rounded edge  
which is so positioned that it bears against the bolt 3 mm from and parallel to the fore -end, apply the  
force in a direction perpendicular to the securing face of a bolt and to each of the locking faces of a  
dead bolt, and check for compliance with 4.5.1. 
6.2.8 Strength of staples  
With the staple under test mounted in the normal manner (using the screws supplied) apply without  
shock, a static force of 1 600 N in a direction perpendicular to the inner face of the staple against  
which the bolt(s) would bear, applying the force by means that simulate the position(s) and width(s)  of 
the bolt(s) of the lock or latch. In the case of a staple for a two -bolt lock apply the force twice,  once to 
each bolt position. Then check for compliance with 4.5.1. 
6.2.9 Accuracy of follower  
Mount the lock/latch under test as described in 6.2.1, turn the lever handle or knob first in one  
direction as far as possible and release it, then tu rn it in the other direction (if the unit allows it) as  far 
as is possible and release it. Check for compliance with 4.5.3. 
6.2.10 Strength of spring -bolt spring  
Support the lock/latch in a suitable manner. Apply a force to the end of the spring bolt and  determine 
the minimum force required to depress the spring bolt to within 1 mm of the fore -end, and  check for 
compliance with 4.5.4. 
6.2.11 Security of dead bolt  
Support the lock under test with the dead bolt withdrawn and with the fore -end horizontal and facing  
upwards. Support a mass of 1.5 ± 0. 1 kg on the end of the dead bolt and use the key to check for  
compliance with 4.5.5. 
6.2.12 Plating tests  
a) Zinc plating . Use the relevant method given in ISO 2081  to determine the thickness of zinc  
coating . 
b) Nickel plating . Use either or (in cases of doubt) both of the relevant methods given in ISO 1458 to 
test the adhesion of the coating, and use the relevant method in ISO 1458 to determine its  thickness.  
c) Chromium on nickel plating . Use the relevant metho ds given in ISO 1456 to test the adhesion  of 
the coatings and to determine their thicknesses.  
 
   MEDC 02 (400) DTZS  
16 
 6.2.13 Corrosion resistance of paint coatings  
Use the apparatus and procedure given in ISO 9227 , to test painted units or components in the  "as 
received" condition. Examine for compliance with 4.6.3. 
 
7 Packaging  and Marking  
7.1 Each lock and/or latch  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 lock and/or latch  shall be marked with the following information:  
 
a) manufacturer's name or initials or trademark;  
b) batch number;  
d) country of origin;  
 
7.3 Each lock and latch  shall be marked with the following information:  
a) manufacturer's name or initials or trademark;  
b) batch number;  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   MEDC 02 (400) DTZS  
17 
 ANNEX  A 
(Informative)  
Notes to purchasers  
A.1 The following requirements must be specified in tender invitations and in each order or  contract:  
a) the  type of lock/latch and whether left - or right -handed (see 4.1.1); 
b) in the case of cylinder mortice locks, whether single - or double -cylinder versions are required  (see 
4.1.1(a));  
c) when relevant, the type of set (see 4.1.2);  
d) the  design of furniture and the type of finish required on cylinder assemblies and fore -ends  (see 
4.1.3); 
e) the number of keys to be supplied with each lock/latch ( see 4.4.1) 
f) when relevant, the type of latch spring action required (see 4.4.3);  
g) when rel evant, the type of striking plate ( see 4 .4.4);  
h) when relevant, the nominal overall length and width of the fore -end, (see figures 1 and 2).  
A.2 It should be noted that  
a) in general, 2 -lever locks should not be used on doors that give external access to premises  unless 
at least one other auxiliary security device or a second more secure lock is also fitted;  
b) in determining the relative security of double -sided type lever lo cks the number of "different"  levers 
in a lock can be more important than the actual number of levers.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   MEDC 02 (400) DTZS  
18 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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