Thick bosses on thin walls
- Sink on cosmetic faces
- Long cycle waiting on thick sections
DFM
Wall Thickness: Injection Molding Design Rules
Wall thickness sets fill, pack, cooling, and warp risk on every molded part.
DFM
Pick a nominal wall before you detail ribs and bosses
Rules NetProto DFM review checks against before steel is ordered.
Thin sections fill faster but need resin with enough flow length. Thick sections hold sink and warp risk.
NetProto DFM review flags abrupt thickness changes that create hesitation marks or voids.
Thickness plan
Uniform target versus accidental thick bosses
Bosses and ribs should reference a primary wall, not invent new thick islands.
Ribbed thin wall design
- Ribs carry stiffness at ~60 percent of nominal wall
- Bosses cored or tied to nominal wall
CAD checklist
Send this with your upload
Missing DFM inputs delay qualified quotes.
Nominal wall callout on drawing
Boss and rib thickness notes
Material grade for flow length
Related rules
Design guide
Jump to sibling rules before you freeze CAD.
Design guide hub
All DFM topics on one route.
Design guide hubDFM article
Long form engineer guide.
DFM articleDraft angle
Design rules for draft angle.
Draft angleRib design
Design rules for rib design.
Rib designUndercuts
Design rules for undercuts.
UndercutsFAQ
Common questions
What wall thickness is typical?
Many ABS and PP parts live near 1.5 to 3 mm depending on size and resin.
Will thick walls always sink?
Not always, but thick sections without coring are a top sink driver.
Next step
Upload CAD for DFM-aware quoting
One hardened steel tool quote with piece price on the same upload.