Cut and bent steel reinforcement bar in Shape 21 Common names. 1. U-shaped rebar 2. Bent-up bar 3. U-stirrup 4. U-bend reinforcement Shape Code 21 vs Shape Code 13. Shape Code 21: This code represents a U-shaped rebar without the circular gap at the bent part. It is a regular U-shaped rebar, meaning it doesn’t leave a gap at the bent point, making it a perfect 90° Degree bent. Shape Code 13: This code represents an U-shaped rebar with a circular bend that form a gap at the bent part. These descriptions highlight the difference between shape code 21, which features a circular gap in the bend of the U-shaped rebar, and shape code 13, which does not have this circular gap. Shape Code 21 Image - Showing 90° Degree bent Shape Code 13 Image - showing a gap in the radios bent point. All sizes available: 8mm Custom Cut & Bent Rebar in Shape 21 10mm Custom Cut & Bent Rebar in Shape 21 12mm Custom Cut & Bent Rebar in Shape 21 16mm Custom Cut & Bent Rebar in Shape 21 20mm Custom Cut & Bent Rebar in Shape 21 25mm Custom Cut & Bent Rebar in Shape 21 32mm Custom Cut & Bent Rebar in Shape 21 40mm Custom Cut & Bent Rebar in Shape 21 Order online custom bent rebars or send us your rebar bending schedule.