MIM processing normally requires a dimensional tolerance of ±.003 inches/inch
(±0.3percent). As part size decreases, increasingly tighter total tolerances can
be achieved, as would be expected. However, the reduction in tolerances is not directly
proportional to decreasing dimensions and may depend on material, part shape, and
process requirements. A tolerance of ± 0.1 percent can generally be held on a small,
selected dimension when the mold has been “fine-tuned”. Typical tolerances for MIM
parts, over a range of dimensions, are shown in Table II for both standard and specialprocessing. Geometrical tolerances are shown in Table III.
Extremely tight tolerances may have to be obtained through machining:
Tolerances specified should be no
closer than absolutely required for satisfactory performance.