Neutral Axis In Sheet Metal

When metal is bent the top section is going to undergo compression and the bottom section will be stretched.

Neutral axis in sheet metal.

When the sheet is flat without any applied stress the neutral axis is in the middle of the sheet. The line where the transition from compression to stretching occurs is called the neutral axis. K factor is a ratio that represents the location of the neutral axis with respect to the thickness of the sheet metal part and depends on material thickness and bend radius. The k factor in sheet metal working is the ratio of the neutral axis to the material thickness.

But add a little stress and force the metal to bend and watch what happens. When metal is bent the top section is going to undergo compression and the bottom section will be stretched. When a piece of metal is being formed the inner portion of the bend compresses while the outer portion expands see figure 1. K factor a constant determined by dividing the thickness of the sheet by the location of the neutral axis which is the part of sheet metal that does not change length.

K factor in sheet metal bending is a constant used to calculate sheet metal flat length or flat pattern. The bend allowance describes the length of the neutral axis between the bend lines or in other words the arc length of the bend. The bend allowance and bend deduction are two measures that relate the bent length of a piece of sheet metal to the flat length. Mathematically k factor value is equal to the ratio of position of neutral axis and sheet thickness.

The line where the transition from compression to stretching occurs is called the neutral axis. Where t is the distance. The granular bonds are stretched pulled and sometimes break forcing the grains apart as they come under tensional stresses. The location of the neutral axis for a specific sheet is defined by a factor called k factor.

So if the thickness of the sheet was a distance of t 1 mm and the location of the neutral axis was a distance of t 0 5 mm measured from the inside bend then you would have a k factor of t t 0 5 1 0 5.