MEDC 02 (1016)  DTZS  
 
ICS: 77.140.65  
   
 
 
 
 
 
 
DRAFT TANZANIA STANDARD    
 
Cold drawn mild steel wire for general engineering purposes ― Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARDS    
 
© TBS 2021            Fourth  Edition  2021  
  
 MEDC 02 (1016)  DTZS  
 
 
This Tanzania standard was published under the authority of the Board of Directors of Tanzania 
Bureau of Standards in 2021 . 
 
Tanzania Bureau of Standards (TBS) is the statutory national standards body for Tanzania 
established under the Standards Act No. 3 of 1975 which was later repealed and replaced by the 
Standards Act No. 2 of 2009.  
 
The Mechanical Engineering Divisional Stan dards 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 Development Corporation  
National Institute of Transport (NIT)  
Ministry of Works  
Weights and Measures Agency   
Tanzania Industrial Research Development Organization (TIRDO)  
ALAF Limited  
Dar es Salaam Institute of Technology  
 
The following organizations were directly represented on the Techn ical Committee entrusted with 
the preparation of this Tanzania Standard:  
 
MM Integrated Steel Mills Company Limited 
ALAF Limited   
Tanzania Automotive Technology Centre (TATC)  
TAPCO Ltd  
Dar es Salaam Institute of Technology  (DIT)  
University of Dar es Salaam - CoET  
National Development Corporation (NDC)  
 
 
 
 
 
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:  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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©TBS 2021  – All rights reserved  
  
 DRAFT TANZANIA STANDARD                                                         MEDC 02 (1016) DTZS     
Cold drawn mild steel wire for general engineering purposes ― 
Specification   
 
0 Foreword  
 
In formulating this standard, due consideration was given to international co -ordination among the 
practices prevailing in different countries in addition to rel ating it to the practices in the field in this 
country.  
 
This Tanzania Standard is a revision of the second version published in 2009. This third edition 
cancels and replaces the second edition (TZS 11:2009) which has been technically revised.  
 
In the preparation of this standard, reference was made to the following publications:  
 
a) IS 280: 1972, Mild steel wire for general engineering (second revision) , published by 
the Indian Standards Institution.  
 
b) BS 443: 1982, Specification for galvanized coatings on  round steel wire,  published by the 
British Standards Institution.  
 
c) IS 4826: 1968, Specification for galvanized coatings on round steel wire,  published by 
the Indian Standards Institution.  
 
In reporting the result of a test or analysis made in accordance w ith this standard, if the final 
value, observed or calculated is to be rounded off, it shall be done in accordance with TZS 4, 
Rounding off numerical values.  
 
 
1 Scope  
 
1.1 This Tanzania Standard specifies the quality requirements, dimensions and sampling of cold 
drawn mild steel wire of sizes 1 -mm to 10 -mm diameter for general engineering purposes  
with exception of fencing applications . 
 
      1.2 Steel wires and steel wire products for fencing are covered in TZS 1795.  
 
 
2 Reference  
 
For the purpose of this s tandard, the following references shall apply:  
TZS 9, Steel ― Methods of testing zinc coating on wire  
 
TZS 10, General requirements for the supply of metallurgical materials  
 
TZS 12, Steel ― Tensile testing of wire  
 
TZS 13, Steel ― Wrapping test of wire  
 
TZS 14, Steel ― Plain carbon ― Determination of sulphur by combustion method  
 
TZS 15,  Steel ― Determination of phosphorus by alkalimetric method  
 
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Order # NUMBER/Downloaded: 2019 -10-21 
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 MEDC 02 (1016) DTZS  
 
3 Terminology  
 
For the purpose of this standard, the following definitions shall apply:  
 
3.1 Wire rod  
 
A semi -finished hot -rolled mild steel product capable of being drawn into wire of required 
diameter  
 
3.2 Wire  
 
A product of a wire rod whose sectional area has been reduced at normal temperatures either by 
drawing through a specially prepared orifice or passing under pressure between suitably driven 
rolls 
 
3.3 L ength  
 
A straight piece of a drawn or rolled wire cut to a specified or random length  
 
3.4 Coil  
 
A continuous length of wire drawn and rolled in the form of a reel  
 
3.5 Lot  
 
Any quantity of coils of wire of the same thickness from which test samples shall be taken.  
 
 
4 Supply of material  
 
General requirements relating to the supply of mild steel wire shall be as laid down in TZS 10 
(see Clause 2).  
 
 
5 Dimensions  
 
The nominal diameters and tolerances of mild steel wires shall be as specified in Table 1.  
 
Table 1: Diameters of mild steel wires   
 
Nominal value   
1.00 
1.12  
1.25 
1.40 
1.60  
1.80 
 
2.00 
2.24 
2.50  
2.80  
 
Tolerance  
 
 
 
 
± 0.04   
 
Nominal value   
3.15 
3.55  
4.00 
4.50 
5.00  
5.60 
 
6.30 
7.15 
8.00  
9.00 
10.00    
 
Tolerance   
 
 
± 0.05 
 
 
 
 
 
 
± 0.06 
 
 
 
 
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2 Single -user licence only, copying and networking prohibited.  
 
©TBS 2021  – All rights reserved  
  
 MEDC 02 (1016) DTZS  
 
 
6 Quality requirements  
 
6.1 Chemical composition  
 
The base metal of which the wires shall be drawn, shall be mild steel having not more than 0.06% 
of phosphorus or sulphur when analyzed in accordance with TZS 15 and TZS 14 (see Clause 2) 
respectively.  
 
6.2 Manufacture  
 
The wire shall be cold drawn. It shall be drawn to the specified nominal diameter, and shall be 
sound and free from splits, surface flaws, scale and other manufacturing defects.  
 
6.3 Finish  
 
The wire shall have one of the following finishes:  
 
a) bright drawn  
b) annealed  
c) galvanized (zinc coated)  
 
6.4 Mechanical properties  
 
6.4.1  Tensile test  
 
The tensile strength ( Rm) of the wire shall not be less than 550 N/mm2 when tested according to 
8.2. In case the wire is anneale d, the tensile strength shall b e between 310 N/mm and 430 
N/mm2 for wires of diameter 1.6 mm and above and shall not exceed 490 N/mm2 for wires of 
diameter 1.4 mm and below.  For high tensile wire then the tensile strength should range from 
900MPa to 1800MPa.  
 
6.4.2  Wrapping test  
 
A wire s maller than 5 mm diameter shall withstand without breaking or splitting being wrapped 
eight times round its own diameter and subsequently straightened when subjected to wrapping 
test in accordance with 8.2.  
 
6.4.3  Bend test  
 
A wire of 5 mm diameter and ove r shall withstand being bent through an angle of 90º round a 
former of diameter equal to twice its own diameter without breaking or splitting.  
 
 
7 Sampling  
 
7.1 Samples for test purposes shall be taken at random from lots according to Table 2.  
 
Table 2:  Number of coils to be selected from lots  
 
Number of coils in the lot  Number of coils to be selected  
Up to 25  3 
26 to 65  4 
66 to 180  5 
181 to 300  7 
Above 300  10 
 
  
   
  
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©TBS 20 21 – All rights reserved  
  
 MEDC 02 (1016) DTZS  
 
7.2 From one end of the coil or length of wire selected, two separate test pieces at a distance of 
not less than 600 mm from the end shall be cut. One test piece shall be used for tensile test and 
the other for the wrapping test or bend test dependin g on its diameter as specified in 6.4.  
 
8 Tests  
 
8.1 All the coils sampled shall be examined for compliance with the requirements specified in 6.2.  
 
8.2 Tensile test and wrapping test shall be conducted according to TZS 12 and TZS 13 (see 
Clause 2) respectively and the product shall comply with the requirements specified in 6.4.  
 
8.3 Methods of testing zinc coating shall be as specified in TZS 9 (see Clau se 2), the mass of 
coating shall conform to the requirements given in Table 3 and the coating shall be able to 
withstand the specified number of dips.  
 
Table 3 : Minimum mass  of coating and number of dips   
       
Nominal diameter 
of coated wire  
mm Heavy  Medium  Commercial  
mass  of 
coating  
g/m2 Number of dips  mass  of 
coating  
g/m2 Number of dips  mass  of 
coating  
g/m2 Number 
of dips  
Above  Up to and  
including  1 min  1/2 min  1 min  1/2 min  1 min  
0.90 1.0 170 2 - 150 1 1 27 no test  
1.00 1.25 180 2 - 160 2 - 34 1 
1.25 1.40 200 2 - 180 2 - 40 1 
1.4 1.60 210 2 - 190 2 - 50 1 
1.60 1.80 230 2 1 200 2 - 56 1 
1.80 2.00 240 3 - 210 2 - 69 1 
2.00 2.24 260 3 - 210 2 - 69 1 
2.24 2.50 260 3 - 230 2 1 72 1 
2.50 2.80 270 3 - 230 2 1 72 1 
2.80 3.15 270 3 1 240 3 - 72 1 
3.15 3.55 280 3 1 250 3 - 78 1 
3.55 4.00 290 3 1 260 3 - 80 1 
4.00 5.00 290 3 1 275  3 1 85 1 
5.00 7.00 300 4 - 290 4 - 100 1 
7.00 10.00     300 4 -   
 
 
9 Retest  
 
9.1 Should any of the test pieces first cut from the samples not fulfill the test requirements 
specified in clause 8, two additional test pieces taken at random from another coil of the same lot 
in respect of each failure shall be taken from the samples.  
9.2 Should both the additional test pieces pass the test, the lot represented shall be accepted as 
conforming to this standard, provided it complies with all the other requirements specified in this 
standard.  
9.3 If either of the test pieces fails the retest, the lot shall be rejected.  
  
 
  
 
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     MEDC 02 (1016) DTZS  
 
 
10 Packaging  
 
Finished wire coils may be wrapped with suitable material, e.g. jute, sisal or bituminous paper in 
order to prevent rust development.  
 
 
11 Marking  
 
Coils of cold drawn mild steel wire shall legibly and durably be marked with the following 
information:  
 
a) Finish;  
b) Size and quantity;   
c) Lot number and date manufactured;  
d) Name of manufacturer and trade mark, if any;   
e) Outgoing inspection certificate report number; and  
f) Country of origin.  
 
 
12 Designation  
 
In making orders and in all commercial and technical documents, coils of cold drawn mild steel 
wire (CMSW) shall be designated as follows:  
 
CMSW/Finish/Diameter/TZS  
 
Example:  
 
CMSW/Bright/4.50/TZS 11: 2021 means cold drawn mild steel wire with a bright finish of diameter 
of 4.50 mm as specified in TZS 11: 2021. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
   
  
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 MEDC 02 (1016) DTZS  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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