Machining
When supplied as extruded bar or sheet, POM may be machined using traditional methods such as turning, milling, drilling etc. These techniques are best employed where production economics do not merit the expense of melt processing. The material is free-cutting, but does require sharp tools with a high clearance angle. The use of soluble cutting lubricant is not necessary, but is recommended.
Because the material lacks the rigidity of most metals, care should be taken to use light clamping forces and sufficient support for the work piece.
Machined POM can be dimensionally unstable, especially with parts that have large variations in wall thicknesses. It is recommended that such features are ‘designed-out’ e.g. by adding fillets or strengthening ribs. Annealing of pre-machined parts before final finishing is an alternative. A rule-of-thumb is that in general, small components machined in POM suffer from less warping.
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