General Tolerances

These tolerances apply as a general rule of thumb. Closer tolerances can be obtained depending on part design or the use of special procedures or secondary operations.

Straightness

Tolerances for axial straightness: ±.005"/inch as cast.

Angles

As-cast tolerances of angles depend on their location in casting. They range from ± 1/2° for well supported positions to ± 2° where inherent distortion could be expected. Inclusion of gussets and ribs often minimizes distortion and many sections can be mechanically straightened.

Blind Holes

Blind holes can be cast if length does not exceed the diameter. In nonferrous materials, blind holes under 2" may be cast if length does not exceed twice the diameter.

Hole Positioning

0.127 mm per 25 mm from any single reference point.

Surface Finish

Average Ra value generally ranges between 60 - 125 RMS

Round Hollow Tubing

Tubular section out of-roundness may be altered mechanically according to wall thickness and ductility. Tolerances are as follows:

Casting Tolerances

Flatness 

Flatness refers to single plane surface and is usually a function of volumetric shrinkage.

Concentricity