Tolerance on Bar Manufacture

Tolerances on Bar Manufacture (AS/NZS 4671)

(a) Chemical composition

A cast analysis and a product analysis is required.

Carbon content of reinforcing steel

An upper limit is given for the cast analysis. This is made while the steel is in a
liquid form and therefore while the composition of the steel can be adjusted.

Due to changes during casting of billets and subsequent rolling into the
finished product, slightly higher limits are allowed for the product analysis.

(b) Drawing/Rolling tolerances

Mass/unit length           ± 4.5%

(c) On bar length (bars AS/NZS 4671)

L ≤ 7 m                       + 0, - 40 mm
L > 7 but < 12 m        + 40, - 40 mm
L ≥ 12 m                     + 60, - 40 mm

(d) Straightness on length L, in units of L

Bar sizes ≤16 mm         L/50
Bar sizes ≥ 20 mm        L/100

(e) Deformations

There are no tolerances given for deformations. Values are maximum or
minimum. See Clause 7.4 and Appendix C3 of AS/NZS 4671.

(f) Manufacturer and Mill Identification

The distance between the identifying marks (deformed bars), equals the
circumference of the rolls which have the deformations cut into them. Identifiers
are usually on one side only. They identify the steel maker and the rolling mill.

(g) Mesh tolerance between adjacent wires

Distance                     ±0.075 x pitch

(h) Mesh sheet size

Dimension                  ≤ 6000 mm ±40 mm
Dimension                  L > 6000 mm ±0.007 L