Bends

Bends should be toleranced plus or minus onehalf
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 onehalf the material thickness or 0.80 mm (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 the edge
of a hole is the radius of the curl plus the material thickness.

The minimum distance a 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 a maximum depth of onehalf 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 an 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 1.50 mm (0.06 inch), whichever is greater.
Gussets

The width and depth, recommended at an angle of 45
degrees, 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 1.00 mm (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 lance is two
times the material thickness or 3.00 mm (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 1.60 mm (0.06 inch), whichever is greater,
and a maximum height of five times the material thickness at a 45degree
angle.

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

The minimum distance from a lance to a bend in 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.
Notches

The minimum width is equal to the material thickness
or 1.00 mm (0.04 inch), whichever is greater.

The maximum length for a straight/radius end notch
is equal to five times the width.

The maximum length for a V notch is equal to two
times the width.

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

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

The minimum distance from a notch to a bend in a
perpendicular plane is three times the material thickness plus the radius
of the bend.

The minimum distance beyond the bend on the side
edge is equal to the thickness of the material plus the bend radius, or
two times the material thickness, whichever is greater.

The minimum distance between two notches is two times
the material thickness or 3.200 mm (0.125 inch), whichever is greater.
Ribs

The maximum inside radius is equal to three times
the material thickness, with a maximum depth of the inside radius.

The minimum distance from a center line of a rib
to the edge of a hole is three times the material thickness plus the radius
of the rib.

The minimum distance a rib should be from an edge
in a perpendicular plane is four times the material thickness plus the
radius of the rib.

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

The minimum distance a rib should be from a bend
perpendicular to the rib is two times the material thickness, plus the
radius of the rib, plus the radius of the bend.

The minimum distance between two parallel ribs is
ten times the material thickness plus the radii of the ribs.
SemiPierced Hole

The minimum distance from a semipierced hole and
a form is three times the material thickness plus the form radius.

The minimum distance from a semipierced hole and
a bend is two times the material thickness plus the bend radius.

The minimum distance between semipierced holes is
eight times the material thickness.
Slots

The minimum width of
a slot is equal to the material thickness or 1.00 mm (0.04 inch), whichever
is greater.

The minimum distance from the inside surface of a
bend to the edge of a slot is directly proportional to the length of the
slot, material thickness, and radius of the bend.

When using slots and tabs the maximum width of the
slot must be greater than the thickness of the tab and the tab length should
equal the material thickness.
Tabs

The minimum width is equal to two times the material
thickness or 3.200 mm, whichever is greater, while the maximum length is
five times the width.

The minimum distance between tabs is equal to the
material thickness or 1.00 mm (0.04 inch), whichever is greater.
Welding

Spot welding should be restricted to joining coplanar
surfaces.

The minimum distance between welds is 10 times the
material thickness. Using 20 times the material thickness is ideal.

The minimum distance between a weld and the edge
is two times the diameter of the spot weld.

The minimum distance from a weld to a form is the
spot diameter plus the bend radius.

Use PEMs instead of threaded inserts.
Plating

Outside sharp corners receive twice as much plating
as flat surfaces.

Allow for pitch diameters for screw threads, which
can increase four times the plating thickness.

Tapped holes may need to be retapped after plating
to ensure accuracy.

Projections accumulate more plating than other areas.

Recessed areas may be difficult to plate, resulting
in little or no coverage.

Lapwelded joints trap plating solutions. One
solution is to raise welds on embossed areas by 0.015 in. (0.3 mm)
to allow for flushing and blow drying between the surfaces.

Masking of stampings and fabrications to anodize
certain areas is not recommended.

Design drain holes/vent holes for plating solutions
and rinsing.

Design tabs/holes for attachment to part racks.
