Injection Molding Part Design — For Dummiespdf Exclusive

Avoid placing critical structural loads directly on top of a predicted knit line location. Quick Reference Design Checklist Design Rule Summary Maintain uniform thickness; avoid sudden changes. Draft Angles

Apply a minimum draft of 1° to 2° per side . Deep or textured parts require more (3° or higher).

Sharp corners create high stress concentration points. They restrict plastic flow during injection and act as failure points when the part is put under real-world pressure. Radius Recommendations injection molding part design for dummiespdf exclusive

Inside radii should be at least 50% of the adjacent wall thickness.

What is the of your part (cosmetic casing, structural bracket)? Will the part include threads or snap-fits ? Avoid placing critical structural loads directly on top

According to major industry guides, successful part design focuses on to eliminate defects like warping or sink marks. Draft Angle Guidelines for Injection Molding - Protolabs

Bosses are cylindrical features used to accept screws or pins during product assembly. Deep or textured parts require more (3° or higher)

: Bosses are the cylindrical protrusions used for screws or pins. Like ribs, they can cause sink marks if they are too thick. They should be supported by gussets (small triangular ribs) for stability rather than just being thickened at the base. Material Selection

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Beginners often try to make a part stronger by making it thicker. As we discussed, thick walls lead to sink marks. The professional solution is to use ribs.