AS/NZS 4671: steel for the reinforcement of concrete
AS/NZS 4671:2019 sets grades, test methods, and ID markings for reinforcing steel in concrete. Called up by AS 3600 and the NCC Housing Provisions as DTS.
Ask Chalkline about this →AS/NZS 4671 is the joint Australian and New Zealand standard for steel used to reinforce concrete. The current edition is AS/NZS 4671:2019. It defines the grades, mechanical properties, dimensional tolerances, test methods, and identification markings for reinforcing bar and mesh and is the deemed-to-satisfy specification called up by AS 3600 (concrete structures) and the ABCB Housing Provisions Part 4.2 (footings and slabs).
Grades
The standard names grades by nominal yield strength plus a ductility class suffix:
- 250N: 250 MPa yield, normal ductility (rare in current AU practice).
- 500L: 500 MPa yield, low ductility, mesh / fitments only.
- 500N: 500 MPa yield, normal ductility, general reinforcing bar.
- 500E: 500 MPa yield, earthquake (high) ductility, seismic / special applications.
Most residential bar is 500N (deformed bar, the bumpy reo); mesh is typically 500L; columns and beams in commercial work may use 500E where AS 3600 requires the higher ductility class.
What the standard controls
- Chemical composition of the steel.
- Mechanical properties: yield strength, tensile strength, elongation, ductility ratio.
- Bar dimensions and mass per metre within tolerance bands.
- Surface deformations (the ribs) for bond with the concrete.
- Identification marks rolled into the bar showing producer, grade, and bar size.
The delivery docket is the on-site control: it nominates the standard (AS/NZS 4671), the grade (e.g. 500N), the bar diameters, and the producer. A docket that doesn’t name AS/NZS 4671 and a recognised producer is not proof of compliant material.
How it sits in the wider compliance picture
| Step | Where compliance lives |
|---|---|
| Design loads, exposure class | AS 3600 and NCC Housing Provisions |
| Reinforcement specification (grade, size) | AS 3600 + the engineer’s design |
| Reinforcement product compliance | AS/NZS 4671 (this standard) |
| Cover, fixing tolerances | AS 3600 Section 4 |
| Placement workmanship | steel fixer trade discipline |
AS/NZS 4671 governs only the steel itself. Design uses it; placement assumes it.
For a builder
- Read the delivery docket every time. The grade and the standard reference are the proof. Reject any delivery without a docket naming AS/NZS 4671.
- Don’t substitute grades on the job. Swapping 500L mesh for 500N bar in a slab is a structural change, not a procurement tweak.
- Keep the docket with the slab record. Certifier may ask for it at the pre-pour or final inspection; missing dockets are a defect even where the steel was correct.
Related
See also
Last updated: 2026-05-29. Verified: 2026-05-29. Quarterly review for currency.