Rebar Shape Codes Reference Guide: Shapes 20 to 86 and Applications

Shape Code 20

Straight Reinforcing Bars

The most basic straight reinforcing bars are primarily used as straight distribution reinforcement in walls and slabs, or as longitudinal main reinforcement in beams and columns.

Shape Code 37

Single 90° Right-Angle Bend (L-Shaped Rebar)

Reinforcing bars with a right-angle bend at one end are commonly used for connections at beam-column joints, wall corners, and end anchoring at the edges of slabs.

Shape Code 38

Double 90° Elbow Rebar (U-Shaped/Channel-Shaped Rebar)

Both ends are bent upward at right angles; this is commonly used for finishing and sealing the ends of beams and walls, or as lateral restraint reinforcement at the edges of structural members.

Shape Code 39

Single-Ended Semicircular Hook Rebar

Straight rebar with a 180° semicircular hook at one end can significantly enhance the end’s resistance to pull-out and slippage within concrete.

Shape Code 41

One-Way Duck-Neck Reinforcement (with a Straight Section and a Single-Slope Segment)

Featuring a sloped transition section and a height difference, these are used for lap splices at points where column cross-sections change, or as bent stirrups in the midspan of beams to resist shear forces from oblique sections.

Shape Code 42

Curved ribs with end bends

After being bent diagonally upward, the end is then folded downward at an angle; this is commonly used for diagonal shear reinforcement at beam ends and provides reliable hook anchorage at the ends.

Shape Code 43

Bidirectional W-shaped bending reinforcement

Features multiple consecutive diagonal bends and undulations; used for special shear members, reinforcement of shear zones, or diagonal reinforcement in continuous beams.

Shape Code 45

Diagonally Extending End Ribs、

It slopes diagonally and then extends downward at the end, making it suitable for special end anchoring on sloped roofs, staircases, and the ends of beams with variable cross-sections.

Shape Code 48

Obtuse-Angle Bending Rebar

Straight sections with shallow upward bends are used for reinforcing folded-line floor slabs, transition sections of folded beams, or members with varying angles.

Shape Code 49 

Shallow Groove / V-Shaped Recessed Bend Reinforcement

This reinforcement features a shallow groove-shaped bend and is commonly used at the lowered slab locations in sunken bathrooms, in transition sections of drainage pits, or to reinforce localized recesses.

Shape Code 51 

Bent Rebar with Specified Radius

Features a specific arc radius $r$ at the bend; commonly used for turning large-diameter primary reinforcement to prevent concrete crushing caused by excessive bending of the rebar.

Shape Code 52 

Open U-Shaped/Box-Shaped Stirrups

A frame-shaped stirrup enclosed on three sides and open at the top, commonly used as open stirrups on the top of beams or as internal restraint stirrups within hidden columns.

Shape Code 53 

Cap-Shaped / Convex Offset Stirrups

Featuring a local “凸”-shaped undulation, these are used to span embedded pipes, equipment recesses, or to reinforce areas with localized concentrated loads.

Shape Code 54 

Z-Shaped / S-Shaped Stepped Stirrups

Featuring upward and downward opposite-direction bends forming a stepped pattern, these are commonly used for connecting floor slabs of varying heights, transition sections in shear walls, and construction joint overlaps.

Shape Code 55

 Open-Ended Frame Stirrups (with Barbs)

Enclosed on three sides with ends bent inward or upward, these are commonly used as stirrups in composite beams, precast composite beams, and frame beams with precast slabs.

Shape Code 60 

Closed Rectangular Hoop Reinforcement

The most standard closed quadrilateral hoop reinforcement, used in beams and columns for shear resistance, torsional resistance, and to secure the main longitudinal reinforcement.

Shape Code 62 

Shallow-Angle Diagonal Reinforcement

A straight segment followed by a shallow-angle diagonal segment; commonly used for inclined reinforcement in pitched roofs, slabs with varying thicknesses, or stair tread slabs.

Shape Code 65 

Arc-Shaped Reinforcing Bar: The entire bar is bent into an arc according to a specified radius $r$. Suitable for circular tanks, arched structures, tangential reinforcement in cylindrical columns, and curved walls.

Shape Code 72 

Double-Open U-Shaped Tie Bar:

The U-shaped opening is folded inward at both ends. Used for spacing control in double-layer reinforcement meshes and lateral confinement of wall edge members.

Shape Code 73

Extending Lap Stirrups

Rectangular stirrups with a straight extension at the top; commonly used for stirrups in edge beams with cantilever slab joints or for node anchoring.

Shape Code 74 

Overlapping Closed Stirrups

These stirrups overlap and interlock at corners to form a closed loop, providing extremely high confinement. They are commonly used in the stirrup densification zones at the ends of beams and columns where high seismic resistance is required.

Shape Code 75

Nested Multi-leg Stirrups

Small stirrups or tie rods are nested inside larger stirrups; these are used as internal shear sleeves for large-section members such as wide beams and multi-leg columns.

Shape Code 81

Flat-Oval Closed Hoop Reinforcement

A closed hoop with semicircular ends, used as lateral confinement hoop reinforcement for oval columns, flat piers, or pipe encasements.

Shape Code 85 

Large U-Shaped Corner Stirrup

Features a long open side and a 180° hook; commonly used for thick foundation mats, wall corner connections, and connections in large-section members.

Shape Code 86

 Helical Rebar / Coiled Rebar

(Helix) Continuously coiled helical rebar used for bored cast-in-place piles, confinement of cylindrical members, and anti-splitting anchorage at the tension ends of prestressed members.