
AS/NZS 4671 Reinforcement
This resource includes the following quick reference information:
- Reinforcing bar dimensions, mass and density and positional tolerances.
- Reinforcing mesh dimensions and properties
- Reinforcement bar development and lap lengths in accordance with AS3600
- Minimum dimensions for standard shapes processed to AS3600
- Standard hooks and cogs to clause 13.1.2.7 of AS3600 – Minimum dimensions
Downloadable Bluebeam Tool Sets for standard shapes
Community
Calculated Values
Cross-sectional area per metre width
Ast = 1 mm²/m
Reinforcement rate (one layer)
rm = 1 kg/m³
Reinforcement ratio p (one layer, %)
p = 1
Allowable deviation in position (AS 3600 Clause 17.5.3)
tp = 1
Mass of reinforcement per square metre
m = 1 kg/m²
Purpose
Areas, mass and position tolerances for D500N deformed reinforcing bars (N10 to N50), for a group of bars or for bars at a spacing in a slab or wall.
Basis
Nominal diameters, cross-sectional areas and masses per metre are those published in AS/NZS 4671:2019 Table 7.5(A), where masses are calculated from the nominal diameter at 7850 kg/m3; the tolerance on mass per metre is ±4.5% (Clause 7.3.1). Group and per-metre areas are the tabulated area multiplied by the number of bars or by 1000/s. The reinforcement rate and ratio are for the single layer described by the inputs. Position tolerances are those of AS 3600:2018 Clause 17.5.3.
Revision
v5 (October 2026): data placed on AS/NZS 4671:2019 Table 7.5(A) (three transcription errors in the area tables corrected, N50 added, mass outputs on the nominal mass, bars per tonne regenerated), mass per square metre added, reinforcement ratio shown as a percentage, inputs and outputs tidied, notes and tooltips added.