Every bar on a bar bending schedule is described partly by a shape code — a two-digit number defined in BS 8666, the British Standard that governs how reinforcing bar is specified, scheduled, cut and bent. If you’ve seen a schedule with a column headed “Shape Code” and numbers like 00, 11 or 33, this is what they refer to.
Why a standard shape code system exists
Before BS 8666, different engineers and fabricators might describe the same bent bar shape in different ways, which is exactly the kind of ambiguity you don’t want on a structural element. The standard shape codes give every bar a precise, unambiguous shape, with lettered dimensions (A, B, C, D and so on) that the schedule fills in for that specific bar — so a “shape code 21” bar with dimensions A=600, B=300 means exactly the same thing to every fabricator in the country.
Some of the most common shapes
- Shape 00 — a straight, unbent bar.
- Shape 11 — a single right-angle bend (an L-shape), commonly used for starter bars and corners.
- Shape 21 — a U-shaped bar with a bend at each end, often used in links and closed shapes.
- Shape 33 — a closed rectangular link (stirrup), widely used to tie main bars together in beams and columns.
- Shape 51 — a helical shape, used for spiral links in columns.
There are dozens of standard shapes in total, covering everything from simple bends to complex spirals — the schedule will always reference the specific code and dimensions needed for each bar.
Why this matters when you order
A bar bending schedule from your engineer, with shape codes and dimensions specified, is exactly what a fabricator needs to cut and bend your bar correctly first time — no guesswork, no site rework. If you don’t have a formal schedule but know roughly what shapes you need, our team can talk it through with you.
See our reinforcement shape codes reference page for the fuller table, or get in touch for a cut-and-bent quote against your own bar bending schedule.
This guide is intended as general background only. The reinforcement your project actually needs — bar size, mesh type, cover, spacing, lap lengths — is set by your structural engineer’s drawings or your building control surveyor, not by a website. Always work to the specification you’ve been given, and if you don’t have one, ask your engineer before you order.
Need reinforcement for your project? Get a fast, competitive quote or call 0207 856 0141 — we deliver rebar and mesh across London and the South East.
