Plastic Injection Molding Part Design Guidelines
UpMold has provided these plastic part design guidelines because we strive to produce your molds and parts perfectly according to your designs. In order to assure that your parts are moldable, please examine the basic guidelines laid out on this page and follow these basic design steps when designing your plastic parts.
Injection Mold Wall Thickness by Resin Material Guidelines
The proper material selection and observing uniform wall thickness in injection molded plastic parts, helps avoid potential issues such as sink marks and warpage. We recommended using the plastic part design guidelines in the table to the right as thicknesses vary by material:
Material | Available Wall Thickness(inches) |
---|---|
ABS | 0.045-0.140 |
Acetal | 0.030-0.120 |
Acrylic | 0.0025-0500 |
Liquid Crystal Polymer | 0.030-0.120 |
Long-fiber Reinforced Plastics | 0.075-1.000 |
Nylon | 0.030-0.115 |
PC(polycarbonate) | 0.040-0.150 |
Polyester | 0.025-0.125 |
Polyethylene | 0.030-0.200 |
Polyphenylene Sulfide | 0.020-0.180 |
Polypropylene | 0.025-0.150 |
Polystyrene | 0.035-0.150 |
Polyurethane | 0.080-0.750 |
Resin | Available Wall Thickness(inches) |
Minimum acceptable wall thickness and layer height
Overall wall thickness should be greater than or equal to the ideal amount, but thinner wall sections greater than or equal to the acceptable minimum are achievable. Wall thickness is geometry and application dependent. We recommend designing load bearing surfaces with ideal thickness or greater.

Plastic part of wall thickness and layer height relationship with resin
Draft angle optimized design guideline
Such as below charts showing that you can according the corrected solutions to optimize your plastic injection molded products
Draft Angle
A taper applied to the faces of the part that prevent them from being parallel to the motion of the mold opening is called draft. This keeps the part from being damaged due to scraping as the part is ejected out of the mold. Recommended draft:
0.5 degrees on all vertical faces is strongly advised.
2 degrees works very well in most situations.
3 degrees is minimum for a shutoff (metal sliding on metal).
3 degrees is required for the light texture.
5 or more degrees is required for heavy texture.