Bend Factor Formulas: Easy-to-Understand Breakdown
When bending sheet metal, the “bend factor” is just the extra length you need to account for—think of it like how a paper clip’s length changes when you bend it. Below are the two most common formulas, explained in plain language:
1. K-Factor Method (Most Common for Precision)
The “K-factor” is a simple number that tells you how much the metal stretches/compresses when bent (it’s usually between 0.3 and 0.5; use 0.4 for regular steel if you’re not sure).
Formula in Plain Words:
Flat metal length = (Length of one straight side) + (Length of the other straight side) + (Small circle math for the bend)
The “Small Circle Math” Broken Down:
For a bend, the metal forms a half-circle (or part of a circle). To calculate that curved part:
- Take π (that’s 3.14, the number for circles)
- Multiply by (Bend radius + half the metal thickness)
- Multiply by (Bend angle ÷ 360) (since 360° is a full circle—e.g., a 90° bend is ¼ of a circle)
Example:
If you bend a 2mm thick steel sheet into a 90° angle (like a “L” shape):
- Each straight side is 50mm
- Bend radius is 3mm
- K-factor is 0.4
Flat length = 50 + 50 + (3.14 × (3 + 1) × (90 ÷ 360)) = 100 + 3.14 = 103.14mm
2. Bend Deduction Method (Simpler for Basic Bends)
This one skips the K-factor and uses a “bend deduction”—a number that tells you how much length is “lost” in the bend (you can get this number from your material supplier’s chart).
Formula in Plain Words:
Flat metal length = (Length of one straight side) + (Length of the other straight side) – (Bend deduction number)
Example:
If your two straight sides are 50mm each, and your supplier says the bend deduction for your metal is 2mm:
Flat length = 50 + 50 – 2 = 98mm
Key Takeaway:
- Use the K-factor method if you need precise parts (e.g., electronics).
- Use the bend deduction method if you’re doing simple bends and have a supplier’s chart.
No need to overcomplicate it—start with these, and adjust if your first bend is a little off!
Read more about sheet metal optimization tips
more photos：https://fuleimetal.com/acf-product/industrial-grade-aluminum-library-book-cart/
#SheetMetal #Bending #MaterialOptimization #SmartManufacturing #CostSaving
(Ideal for fabricators, engineers, and Industry 4.0 professionals.)