Injection Molding Mechanical Tolerances and Surfaces

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Injection Molding Review | Injection Molding Design Guide

Continued from Injection Molding Process Troubleshooting

Injection Molding Mechanical Tolerances and Surfaces:

Molding tolerance is a specified allowance on the deviation in parameters such as dimensions, weights, shapes, or angles, etc. To maximize control in setting tolerances there is usually a minimum and maximum limit on thickness, based on the process used.

Injection molding typically is capable of tolerances equivalent to an IT Grade of about 9-14. The possible tolerance of a thermoplastic or a thermoset is +- 0.008 to +- 0.002 inches. Surface finishes of two to four microinches or better are can be obtained. Rough or pebbled surfaces are also possible.

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