Published
How to back-calculate K-factor from a test bend
A shop-floor method for solving K-factor from a measured coupon bend, including the measurements that matter and the formula behind the reverse K-factor calculator.
Industrial calculators
Sheet Metal Bend Calculators and Fabrication Reference Tools
Shop-math reference for sheet metal, press brake, hydraulic fittings, threads, and grease compatibility. See about and data sources for what each number is built from.
Results are screening estimates and must be verified with your specific material, tooling, equipment, and manufacturer data before production.
K-factorBend allowanceTonnageV-die
Interactive calculator
Quick Bend Allowance Calculator
Bend allowance0.1334 in
Neutral axis radius0.0849 in
Shop notes
Fabrication articles
Published
Why your K-factor changes between air bending and bottoming
A practical explanation of why K-factor shifts between air bending, bottoming, and coining, with shop controls for radius, tonnage, and repeatability.
Published
Springback compensation for 304 vs 316 stainless
How to approach springback in 304 and 316 stainless press brake work, including overbend checks, tooling records, and when to verify with coupon bends.
Static reference
Common thickness, radius, and angle combinations
Swipe table horizontally for more columns.
| Gauge | Thickness | Inside radius | Angle | Bend allowance | Bend deduction |
|---|---|---|---|---|---|
| 20 ga | 0.0359 in / 0.912 mm | 0.0359 in / 0.912 mm | 45 deg | 0.040 in | 0.0194 in |
| 16 ga | 0.0598 in / 1.519 mm | 0.0897 in / 2.278 mm | 90 deg | 0.1804 in | 0.1186 in |
| 14 ga | 0.0747 in / 1.897 mm | 0.0747 in / 1.897 mm | 120 deg | 0.2222 in | 0.2954 in |
| 12 ga | 0.1046 in / 2.657 mm | 0.1569 in / 3.985 mm | 45 deg | 0.1577 in | 0.0589 in |