Bend Allowance

Determine the exact flat pattern length required to achieve a specific bent profile in sheet metal fabrication.

Material & Tooling
Part Dimensions (Outside)
Total Flat Pattern Length
"
Bend Allowance
Bend Deduction
OS Setback

The K-Factor Matrix

The K-Factor represents the location of the neutral axis within the thickness of the sheet metal. When metal is bent, the inside compresses and the outside stretches. The neutral axis is the line where neither stretching nor compression occurs.

Standard K-Factor Guidelines

Material Radius < T Radius 1-3x T
Aluminum (Soft) 0.33 0.40
Steel (Cold Rolled) 0.38 0.43
Stainless Steel 0.40 0.45

Note: These are baseline estimates. For precision fabrication, a K-Factor must be empirically determined by bending test coupons on the specific press brake and tooling that will be used in production.