Bends

Bends should be toleranced plus or minus one-half degree at a location adjacent to the bends.

For the ease of manufacturing, multiple bends on the same plane should occur in the same direction.

Avoid large sheet metal parts with small bent flanges.

In low carbon steel sheet metal, the minimum radius of a bend should be one-half the material thickness or 0.80mm (0.03 inch), whichever is larger.

Counterbores

The minimum distance between two counterbores is eight times the material thickness.

The minimum distance from a counterbore to an edge is four times the material thickness.

The minimum distance from a counterbore to a bend is four times the material thickness plus the bend radius.

Countersinks

The maximum depth is 3.5 times the material thickness at an angle of the hardware.

A minimum of 50% contact between the hardware and the countersink is required.

The minimum distance between two countersinks is eight times the material thickness.

The minimum distance from one countersink and an edge is four times the material thickness.

The minimum distance from a countersink and a bend is four times the material thickness plus the bend radius.

Curls

The minimum radius is two times the material thickness with an opening to a minimum of one material thickness.

The minimum distance between a curl and th edge of a hole is the radius of the curl plus the material thickness.

The minimum distancea curl should be from an internal bend is six times the material thickness plus the radius of the curl.

The minimum distance a curl should be from an external bend is nine times the material thickness plus the radius of the curl.

Dimples

The maximum diameter should be six times the material thickness, and maximum depth of one-half the inside diameter.

The minimum distance that a dimple should be from a hole is three times the material thickness plus the radius of the dimple.

The minimum distance that a dimple should be from the edge is four times the material thickness plus the inside radius of the dimple.

The minimum distance that a dimple should be from a bend is two times the material thickness plus the inside radius of the dimple plus the radius of the bend.

The minimum distance between one dimple and another is four times the material thickness plus the inside radius of each dimple.

Embossments

The maximum depth is proportional to the internal radius or material thickness.

The maximum depth for a flat embossment is equal to the internal radius plus the external radius.

The maximum depth for a V embossment is equal to three times the material thickness.

Extruded Holes

The minimum distance between two extruded holes is six times the material thickness.

The minimum distance from an extruded hole to an edge is three times the material thickness.

The minimum distance from and extruded hole to a bend is three times the material thickness plus the bend radius.

Flanges

The minimum height of a bent flange is directly related to the material thickness, bend radius, and length of bend.

The minimum width of a bend relief is one material thickness or 1.50mm (0.06 inch), whichever is greater.

Gussets

The width and depth, recommended at an angle of 45 degree, is directly proportional to the radius and material thickness.

The minimum distance that a gusset should be from the edge of a hole in a parallel plane is eight times the material thickness plus the radius of the gusset.

Hems

The minimum diameter of a teardrop hem is equal to the material thickness, with a return flange height equal to or greater than four times the material thickness, and a minimum opening of 1/4 of the material thickness.

The minimum diameter of an open hem is equal to the material thickness with a return flange height equal to or greater than four times the material thickness.

The minimum return flange height of a closed hem is equal to or greater than four times the material thickness ( the diameter is zero). Note: Closed hems tend to fracture at the bend and cause entrapment of solutions during the finishing process.

The minimum distance from a hole to a hem is two times the material thickness plus the radius of the hem.

The minimum distance a hem should be from an internal bend is five times the material thickness.

The minimum distance a hem should be from an external bend is eight times the material thickness.

Holes

The minimum diameter of a hole should be equal to the materials thickness or 1.00mm (0.04 inch), whichever is greater.

The minimum distance between holes is directly proportional to the size and shape for the hole feature and the material thickness.

The minimum distance the edge of a hole should be from a form is three times the material thickness plus the form radius.

The minimum distance the edge of a hole should be from a bend is two times the material thickness plus the bend radius.

The minimum distance between a hole and the edge of the material is directly proportional to the size and shape of the hole and the material thickness.

The minimum distance between the leading edge of a hole through a bend should be equal to the thickness of material plus the bend radius or two times the material thickness, whichever is greater.

Lances

The minimum width of an open lanve is two times the material thickness or 3.00mm (0.125 inch), whichever is greater, with a maximum length of five times the width.

The minimum width of a closed lance is two times the material thickness or 1.60mm (0.06 inch), whichever is greater, and a maximum height of five times the material thickness at a 45-degree angle.

The minimum distance from a lance to a bend is a parallel plane is eight times the material thickness plus the radius of the bend.

The minimum distance from a lance to a bend is a perpendicular plane is ten times the material thickness plus the radius of the bend.

The minimum distance from a lance to a hole is three times the material thickness.