AS/NZS 4671 Reinforcement

Purpose Typical minimum dimensions of seven standard bent-bar shapes, for detailing and scheduling D500N and R250N reinforcement to AS 3600:2018 (incorporating Amendments 1 and 2) and AS/NZS 4671:2019. Choose a shape, grade and bar size; the shape is drawn to scale with its minimum dimensions. Basis The tabulated values are typical minimum dimensions to which reinforcement processors bend each shape. Some are set by the bending equipment rather than by AS 3600, so they are not derived from the Standard; every value has been checked to be not less than the AS 3600 minimum for its shape, which the working values print. Pins to Clause 17.2.3.3: 5d_b for bars other than fitments (Item (b)); ties (CT, HT) are fitments, 4d_b for D500N and 3d_b for R250N (Item (a)). Hook extension 4d_b or 70 mm (Clause 13.1.2.7(a)). Dimensions are out-to-out; the table notes say how each is measured. Smaller shapes may be possible by arrangement with the supplier, but not below the AS 3600 minimum. Length of bar The working values give the bend deductions and the length of bar for the shape, by the convention: length = sum of the out-to-out dimensions less (2r_o tan(θ/2) − r_cθ) for each bend of angle θ (a 180° hook instead adds πr_c − 2r_o), on the AS 3600 minimum pin, except the H hook, which uses the pin implied by b. A processor's own pins and schedule govern the cut length. Not covered Bends to be straightened or rebent (Clause 17.2.3.3(c)); epoxy-coated or galvanised bars (Item (d)); N50 and other sizes with no tabulated processing minimum; bending tolerances. The pin sizes are for hot-rolled bar not to be subsequently straightened or rebent. Revision v3 (October 2026): input panel order corrected (Bar size listed with the other inputs). v2 (October 2026): R250N bars added; every v1 value unchanged; minimum pins shown; dimensioned drawing, labelled with every value, in place of the images and the result cards; AS 3600 checks, bend deductions and lengths of bar added; notes and tooltips added.