Radius Design

As with most components, whether metal or plastic, it is good practice all fillets and rounds to all sharp corners. Rounds reduce stress concentration, and provides easier manufacturing in the various plastics production processes (see Figure 1 and Figure 2).

Larger radii are almost always better. As a general guideline, 0.25 x wall thickness is a good minimum radius.

It is important to maintain a uniform wall thickness in plastic parts. Figure 2 shows that the outside and inside edges of a corner should both be rounded to maintain uniform walls.