Machining Parts FAQs

Do molded parts last longer than machined parts?

No, for industrial applications, there is no quantifiable difference in wear life.

Is there a quality difference between extruded, fabricated and molded parts?

Aside from cosmetic appearances, the differences in parts made by each of the various manufacturing processes are very slight and not noticeable in the vast majority of industrial applications. Emco Plastics offers all these options! Our engineers can help you decide what manufacturing technique will work in your particular situation.

When machining polycarbonate, ABS, Noryl®, or Ultem®, I notice that after a period of time cracks are present that are not detectable at the time of machining. What is a possible cause of this?

When machining these materials, use air-cooling when possible or if desired, use a water coolant. Coolants other than pure water may cause stress cracking due to chemical attack. Also, when doing extensive machining, you should machine in steps and perform a stress-relieving operation after rough machining.

Glass-reinforced nylon tends to crack when I attempt to cut it. Why is this and what can I do this occurs?

Glass-reinforced materials tend to have higher residual stresses and therefore are susceptible to cracking during cutting or machining. We suggest heating these products at 120° C for 1 hour per 3/8″ of cross-section prior to cutting or drilling.