Rebar Bending Shape Codes: RSIC Standard Bar Bends Explained

Rebar bending shape codes are short labels for standard bar shapes. In Canada, they come from the Typical Bar Bends table in the Reinforcing Steel Institute of Canada (RSIC) Manual of Standard Practice, which numbers main bar shapes as Types 1 to 26, stirrups as S1 to S11, ties as T1 to T9 (plus T3A), spirals as SP and SP1, and anything else as Type X. A bar list gives the type and the lettered leg dimensions, and the shop bends the bar to match.

This guide walks through how the codes work, what the main families look like and where Canadian codes differ from American and British ones.

How a shape code works on a bar list

Each line on a bar list has a bar mark, quantity, size, total length and a Type column. The type tells the shop which shape to bend. Letter columns then give the dimensions of each part of that shape:

• A to G, K: the legs and hooks of the bar, in the order shown on the type's sketch.
• H: a height or rise, such as the depth of a truss bar's bend or the size of a stirrup hook.
• J: the height of a 180° hook, shown only when the hook size has to be restricted.
• O: an overall dimension, such as the outside length of a bent bar or the outside diameter of a circular tie.
• R: a radius, on radius-bent shapes.

Two RSIC rules apply to every type. First, all dimensions are out-to-out of the bar, except A and G on standard 135° and 180° hooks, which are hook allowances. Second, unless noted otherwise, the bend diameter is the same for every bend and hook on a bar, taken from the standard tables. Our guide to standard rebar hooks covers the hook dimensions.

The shape codes live on bar lists, and the placing drawings show where each mark goes. If you are not sure how the two documents fit together, see placing drawings vs bar lists.

Main bar shapes: Types 1 to 26

The RSIC table numbers its main bar shapes from 1 to 26 (numbers 15 and 21 are not used). They fall into a few families:

Type 26, the standee, is worth singling out because "shape code 26" is a common search. A standee is a bar bent in three dimensions to stand on the bottom mat and hold up the top mat in a thick slab, mat footing or raft. RSIC's bar support table describes a standee as a 10M or 15M bar bent to order. Standees are listed on the bar list like any other shape, so they need to be in the take-off. If your "code 26" came from a British or international bar schedule, it refers to a different system (see below).

Some shapes in the table are rarely used today. RSIC's guidance to designers, for example, says truss bars should not be used unless absolutely necessary.

Stirrup shapes: S1 to S11

Stirrup types are grouped in threes by hook angle, with the hook direction changing within each group:

• S1 to S3: open stirrups with 135° hooks, the H dimension showing how far the hook projects.
• S4 to S6: stirrups with 90° hooks.
• S7 to S9: stirrups with standard 180° hooks.
• S10 and S11: U-shaped hairpin stirrups with a rounded bottom, closed across the top (S10) or open (S11).

Within each group, the hooks point outward, one in and one out, or both inward. RSIC practice is to show the H dimension on stirrups only where it is needed to fit inside the concrete. Stirrup sizes, hook lengths and the 80 mm sizing rule are in our stirrup sizes and hook lengths guide.

Tie shapes and spirals

Column and wall ties have their own series:

• T1 and T2: closed square or rectangular ties, with 135° hooks (T1) or 90° hooks (T2) at a corner.
• T3: a circular hoop closed by a lap. RSIC sets the lap (the G dimension) equal to a Class B tension splice.
• T3A: a circular tie closed with 135° hooks. Its lap (C) is at least 150 mm, or enough to hook the tie around two adjacent vertical bars, whichever is greater.
• T4: a diamond tie, with bends no sharper than 135°.
• T5 and T9: crossties, single bars hooked at each end. A T9 has a 135° hook at one end and a 90° hook at the other, matching the CSA A23.3 rule for crossties.
• T6 to T8: other closed ties, including sloped (trapezoidal) shapes for non-rectangular sections.
• SP and SP1: spirals, given by outside diameter (O), height (H) and pitch (K). For SP1, which has extended end tails (A and G), RSIC notes the tails are at least 24 bar diameters, citing the bridge code CSA S6-19.

Type X and special bending

Any shape not in the table is Type X. It gets its own sketch on the bar list or placing drawing with every dimension shown. Type X bars are fine, but they take more checking, so detailers use a standard type whenever one fits.

RSIC also sorts bending into categories for estimating, which explains why some shapes cost more to fabricate:

• Light bending: all 10M bars, all stirrups and ties, and 15M to 55M bars bent at more than six points, in more than one plane, or to more than one radius.
• Heavy bending: 15M to 55M bars bent at six points or fewer, or radius bent to one radius.
• Radius bending: bends with an inside radius of 300 mm or more, shown as Type 9 or 10.
• Special fabrication: bars bent tighter than the recommended diameter, bent to tighter tolerances, or saw-cut for end bearing.

Tighter bending accuracy is also flagged on the drawings. Under RSIC practice, any dimension that must be bent more accurately than standard tolerance is identified as a critical dimension. Our post on rebar fabrication tolerances lists the standard values.

RSIC, CRSI and BS 8666 codes are not interchangeable

Shape numbering is national, and the same number can mean different shapes:

• RSIC (Canada): Types 1 to 26, S1 to S11, T1 to T9, SP, SP1 and X, with metric bar sizes and CSA bend diameters.
• CRSI (United States): the current CRSI Manual of Standard Practice uses three-digit bend shape numbers (for example, a 400 series for spirals), with inch-pound bar sizes and ACI bend diameters.
• BS 8666 (United Kingdom and many international projects): two-digit shape codes with their own rules, so a "shape code 26" on a British schedule is a different bar from RSIC Type 26.

If a bar list arrives from another country's software, have it re-detailed in RSIC types and Canadian bar sizes before fabrication. Our comparison of ACI and CSA rebar detailing covers the other differences.

Getting shapes right on your bar list

Shape codes make bar lists short and readable, as long as everyone uses the same table. Before you approve a bar list, check that every bent bar has a type, that the letters match the sketch for that type, and that any Type X has a sketch. Our step-by-step guide to reading rebar shop drawings shows how to check marks against the bar list.

Procut prepares bar lists and placing drawings from your structural drawings, then cuts and bends 10M to 55M bar to all standard shapes in our shop. Send us your drawings for a free take-off and quote, or see our services for detailing, fabrication and delivery.