IS 2502 Shape Codes Explained: The Complete Guide (with Diagrams)
Every bar in an Indian bar bending schedule is identified by a shape code — a number that tells the fabricator exactly how the bar is bent, per IS 2502:1963, Code of practice for bending and fixing of bars for concrete reinforcement. This guide covers all 32 shapes used by this calculator, each with its own diagram, so you can identify a shape at a glance instead of cross-referencing a printed chart.
A quick note on IS 2502 vs. BS 8666 shape codes
If you've read our BS 8666 shape codes guide, one thing is worth flagging: the two standards work differently. BS 8666:2020 publishes an official table with a specific cutting-length formula for every numbered shape. IS 2502:1963 doesn't — instead, it sets out general rules for bend deductions and hook allowances by bar size and steel grade, and leaves the detailer to apply them to whatever shape the drawing calls for. The 01–32 numbering used on this page and in the calculator is the widely adopted convention that Indian BBS software and detailers use in practice to refer to the most common shapes consistently.
How IS 2502 calculates cutting length
Rather than one formula per shape, IS 2502 gives two building blocks that apply across all shapes:
- Bend deduction. Every bend shortens the bar slightly compared to the sum of its
straight legs. IS 2502 expresses this as
k × d, where d is the bar diameter and k is 2 for mild steel, 3 for medium tensile steel, and 4 for cold-worked (TMT) bars. - Hook allowance. Where a bar ends in a standard hook, IS 2502 Table II gives a minimum and recommended hook allowance by bar size and steel grade — broadly in the range of 9d–12d depending on the hook angle and bar diameter.
Cutting length is then: sum of the straight legs, plus hook allowance for each hooked end, minus the bend deduction for each bend. Doing this by hand across a full schedule is where errors creep in — which is exactly what the IS 2502 calculator automates.
The shape directory (01–32)
Jump to a shape, or scroll through the full set. 01–03 are straight and hooked bars, 04–18 cover single bends, cranks and offset shapes, 19–29 are links, stirrups and cage ties, 30–31 are helical/spiral shapes for columns and piles, and 32 covers anything non-standard.
- Shape 01 — Straight bar
- Shape 02 — Bar with a standard hook at one end
- Shape 03 — Bar with hooks at both ends
- Shape 04 — Single bend (L-shape)
- Shape 05 — Single bend with hook
- Shape 06 — Bar bent at both ends
- Shape 07 — Cranked bar (single offset)
- Shape 08 — Cranked bar with hook
- Shape 09 — U-shaped bar
- Shape 10 — U-shaped bar with hooks
- Shape 11 — Three-bend bar (open box)
- Shape 12 — Three-bend bar with hook
- Shape 13 — Double-cranked bar
- Shape 14 — Double-cranked bar with hook
- Shape 15 — Four-bend cage member
- Shape 16 — Four-bend cage member (variant)
- Shape 17 — Offset Z-bar
- Shape 18 — Offset Z-bar with hook
- Shape 19 — Open rectangular link
- Shape 20 — Open rectangular link (variant)
- Shape 21 — Standard closed stirrup (rectangular)
- Shape 22 — Closed stirrup, alternate hook detail
- Shape 23 — Circular/polygonal stirrup
- Shape 24 — Cranked bar within a link
- Shape 25 — Cranked bar within a link (variant)
- Shape 26 — Diamond/rhomboid link
- Shape 27 — Triangular link
- Shape 28 — Special cage tie
- Shape 29 — Special cage tie (variant)
- Shape 30 — Helical/spiral link, single turn
- Shape 31 — Helical/spiral link, multiple turns
- Shape 32 — Fully dimensioned / custom shape
No bends. Used for main slab, wall and distribution bars, and for laps.
Calculate shape 01 in the IS 2502 calculator →
A straight bar with a single 180° (or 135°) hook at one end for anchorage.
Calculate shape 02 in the IS 2502 calculator →
A straight bar hooked at both ends — common for top/bottom bars needing anchorage at each support.
Calculate shape 03 in the IS 2502 calculator →
One 90° bend, forming an L — used at corners, kickers and column-to-footing junctions.
Calculate shape 04 in the IS 2502 calculator →
An L-shaped bar with a hook added at the free end for extra anchorage.
Calculate shape 05 in the IS 2502 calculator →
Both ends of the bar are bent in the same direction, forming an open U/staple profile.
Calculate shape 06 in the IS 2502 calculator →
The bar steps between two levels via a diagonal crank — the classic shape for shifting a bar from bottom to top steel across a support.
Calculate shape 07 in the IS 2502 calculator →
A cranked bar with a hook added at one end for anchorage beyond the crank.
Calculate shape 08 in the IS 2502 calculator →
Both ends bent through 90° in the same direction, forming a U — frequently used in open stirrups and wall ties.
Calculate shape 09 in the IS 2502 calculator →
A U-shaped bar with hooks added at both free ends.
Calculate shape 10 in the IS 2502 calculator →
Three bends forming an open rectangular profile — one side of a cage, open at the top.
Calculate shape 11 in the IS 2502 calculator →
The open-box shape above, with a hook added to one leg for anchorage.
Calculate shape 12 in the IS 2502 calculator →
The bar changes level twice, stepping across two different offsets along its length.
Calculate shape 13 in the IS 2502 calculator →
A double-cranked bar with an end hook for additional anchorage.
Calculate shape 14 in the IS 2502 calculator →
A bar with four bends used to close off part of a reinforcement cage or link assembly.
Calculate shape 15 in the IS 2502 calculator →
A close relative of shape 15 with a different leg-length split.
Calculate shape 16 in the IS 2502 calculator →
A bar with two parallel bends forming a stepped Z profile, used where two parallel faces need to be connected with an offset.
Calculate shape 17 in the IS 2502 calculator →
The Z-profile bar above with a hook at one end.
Calculate shape 18 in the IS 2502 calculator →
A near-closed rectangular link left open on one side — a transitional shape between an open cage bar and a full closed stirrup.
Calculate shape 19 in the IS 2502 calculator →
A close relative of shape 19 with a different corner detail.
Calculate shape 20 in the IS 2502 calculator →
The classic closed rectangular stirrup/link used in beams and columns to resist shear and hold main bars in position — the shape most bar bending schedules use most often.
Calculate shape 21 in the IS 2502 calculator →
A rectangular closed stirrup with a different corner/overlap detail to shape 21.
Calculate shape 22 in the IS 2502 calculator →
A closed link bent to a circular or many-sided profile, used for circular columns.
Calculate shape 23 in the IS 2502 calculator →
Combines a crank with a closed-link detail, used where a link also needs to change level.
Calculate shape 24 in the IS 2502 calculator →
A close relative of shape 24 with a different offset arrangement.
Calculate shape 25 in the IS 2502 calculator →
A closed link bent to a diamond or rhomboid profile rather than a rectangle, used in specific column or special-section details.
Calculate shape 26 in the IS 2502 calculator →
A closed link bent into a triangular profile.
Calculate shape 27 in the IS 2502 calculator →
A multi-bend shape used to tie together two layers of reinforcement in a cage — geometry varies by application.
Calculate shape 28 in the IS 2502 calculator →
A close relative of shape 28 with a different bend arrangement.
Calculate shape 29 in the IS 2502 calculator →
A helical link used for circular columns and piles — one continuous turn around the column core.
Calculate shape 30 in the IS 2502 calculator →
The multi-turn version of shape 30, used where a continuous spiral link runs the full length of a column or pile.
Calculate shape 31 in the IS 2502 calculator →
Used when a bar doesn't match any of the standard numbered shapes — it's drawn out and dimensioned in full.
Calculate shape 32 in the IS 2502 calculator →Common mistakes when selecting an IS 2502 shape
- Mixing up similar bend counts. Several shapes in the 04–18 range differ only in leg length or hook placement — check the diagram, not just the bend count, before assigning a code.
- Applying the wrong k factor. Using the mild-steel deduction (k = 2) on a TMT/cold-worked bar (k = 4) will under-state the bend deduction and over-order steel across a schedule.
- Forgetting the hook allowance on both ends. It's easy to add a hook allowance once and forget the second hook on a bar hooked at both ends (shape 03).
- Confusing IS 2502 and BS 8666 numbering. A "shape 21" in IS 2502 and a "shape code 21" in BS 8666 are not the same bar — always confirm which standard a drawing is scheduled to.
Skip the manual lookup
Pick a shape, enter the dimensions, and let the calculator apply the correct IS 2502 bend deduction and hook allowance automatically — then export straight to PDF or Excel.
Open the IS 2502 calculator →Frequently asked questions
Does IS 2502 have an official numbered shape-code table like BS 8666?
Not in the same form. BS 8666:2020 publishes an official table of numbered shapes with a specific cutting-length formula for each. IS 2502:1963 instead sets out general rules for bend deductions and hook allowances by bar size and steel grade, and it's Indian BBS practice and software that has settled on a widely used 01 to 32 shape numbering convention.
What is shape code 21 in IS 2502?
Shape 21 is the standard closed rectangular stirrup — the shape most bar bending schedules use most often, for holding main bars in place and resisting shear in beams and columns.
What's the difference between IS 2502 and BS 8666 shape codes?
IS 2502 is the Indian Standard and BS 8666:2020 is the British Standard for bar bending schedules. They use different shape-numbering conventions, and BS 8666 defines an explicit formula per shape while IS 2502 relies on general bend-deduction and hook-allowance rules, so shape codes do not carry over between the two standards — see our BS 8666 shape codes guide if you're working to the British standard.
How is the bend deduction calculated under IS 2502?
IS 2502 applies a bend allowance based on a factor k times the bar diameter, where k is 2 for mild steel, 3 for medium tensile steel, and 4 for cold-worked (TMT) bars, along with a separate hook allowance depending on bar size.
Working to the British standard instead?
BS 8666:2020 uses its own shape code numbering, with an explicit formula for every shape. Read the companion guide, then build your schedule in the free BS 8666 calculator.
Open the BS 8666 calculator →Not a substitute for a checked, engineer-approved bending schedule. Always verify bend deductions, hook allowances and minimum bend radii against IS 2502:1963 for the actual bar size and steel grade in use.