When sheet metal is bent, the inside surface of the bend is compressed and the outer surface is stretched. Somewhere in between the thickness of material lies neutral axis: Line with-in thickness that is neither compressed nor stretched.
The K-Factor in sheet metal Bending is the ratio of the position of neutral axis to the material thickness. Term k-factor is used in cad programmes to calculate sheet-metal blank size.
Value of k factor will be always less than than 0.5, Value of k factor will be dependent of material, sheet thickness and machine. You can use this calculator for calculating value of k factor in sheet metal for your machine.
Steps To calculate K-Factor
Take a sample sheet of known length and write it down under flat length column.
Bend sheet upto known length with machine for that k factor need to be calculated.
Fill the value of Bend angle, sheet thickness and inside bend radius (value of inside bend radius depends on v die)
Measure the value of bend length A & B
Result column will show the value of bend deduction & K factor