Calculating A Rolling Offset In Sheet Metal

Sheet metal calculator bend allowance equations and calculator.

Calculating a rolling offset in sheet metal.

This is used to calculate the back stop location when working off of a flat pattern. If you are rolling a ring with a 12 inch od out of 25 inch thick material the mean diameter of the ring will be 11 75 inches. Punch edge radius in. Here you would subtract the material thickness from the specified offset.

The first number you need to find when calculating a rolling offset is the true offset which is found using pythagoras theorem. Ultimate tensile strength psi. The following illustration shows the equation calculation for determining the bend allowance when forming sheet metal. In the diagram above the relationship between the travel length and the offsets is as follows.

Windseaker1 sorry for being late getting back yes the bend formula works for rolling as well when you roll a plate you are bending it on a large radius the metal still has to shrink on the inside of the neutral line and stretch on the outside to get a finished diameter that you want you have to compensate by adding or subtracting part of the metal thickness from the neutral line. Step 2 finding the setback and diagonal. 0 059 0 097 in. Say you need to form an offset specified as 0 156 inch in 0 059 in thick material.

This page also includes a link to a on line sheet metal bend allowance calculator. Calculate the square root of the number to find the rolling offset. In the example the square root of 208 14 42 inches. Most sheet metal materials will conform to the calculations.

This simply means that the offset squared plus the rise squared will equal the true offset squared. Die edge radius in. X squareroot square of v square of h travel t x cos 90 fitting angle run r squareroot square of travel t square of x. The length of the material will then be 11 75 x pi or 36 9137 inches.

The resulting number is the offset depth as measured from the material surface. Air bending one of the three types of bending for sheet metal where the outside mold line is not pressed against the die.