Ceramic Parts Dimensional Tolerances
Injection-moulded parts are given a small taper on the sides and in bores, to ease
ejection of the part from the mould. Ceramic parts warp a little during firing.
As-fired ceramic parts have a tolerance of +/- 2% of the dimension or +/- 0.2 mm,
which ever is greater. Closer tolerances are achieved by grinding and lapping. The
table below indicates the tolerances that we can offer. Grinding has to be done
by diamond tools and is a costly operation.
|
Measurement
|
As fired
|
Ground
|
High Precision Ground
|
|
0-10 mm
|
+/- 0.2 mm
|
+/- 0.05 mm
|
+/- 2 microns
|
|
10-50 mm
|
+/- 2%
|
+/- 0.05 mm
|
+/- 2 microns
|
|
50 mm
|
+/- 2%
|
+/- 0.10 mm
|
+/- 4 microns
|
|
Ovality
|
2% of diameter
|
0.1% of diameter
|
2 microns
|
|
Straightness
|
2% of length
|
0.1% of length
|
0.01% of length
|
|
Parallelism
|
1% of length
|
0.1 mm
|
2 microns
|