Direct gate on visible surface
- Fast fill on some geometries
- Vestige and pack mark on Class A
- Higher trim or post gate work
DFM
Gate Types Compared: Injection Molding Design Rules
Gate type controls vestige, shear, and how the part is trimmed after mold open.
DFM
Gate type sets shear, vestige, and degating labor
Edge, tab, direct, and hot drop gates leave different witness marks.
Gate style is chosen with cosmetic class, resin sensitivity, and automation in mind.
Small gates increase shear heat. Large gates extend trim and gate freeze time.
State acceptable vestige locations on CAD before mold design locks gate style.
DFM
Quote this rule with your CAD upload
NetProto DFM review flags these geometry patterns before steel is ordered.
- Call out draw direction and cosmetic faces on the model.
- Note resin family even when the grade is not final.
- Tighten tolerances only on mating features that need them.
Witness
Hidden edge gate versus direct gate on face
Cosmetic faces drive gate economics more than buyers expect.
Edge or tab on hidden parting
- Vestige on break edge or hidden flange
- May need flow length tuning
- Better fit for cosmetics when parting allows
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 articleGate location
Where the gate lands.
Gate locationSub gates
Tunnel and cashew styles.
Sub gatesGlossary gate term
Shared vocabulary with molders.
Glossary gate termVisual reference
Molding context for this rule
Images from the Forge media library illustrate typical programs.
Injection molded part design review on CAD
Injection molded part design review on CAD
Plastic housing with ribs and bosses
Plastic housing with ribs and bosses
Engineer measuring molded component
Engineer measuring molded component
FAQ
Gate type questions
Can gate type change after T1?
Limited steel safe changes. Major style changes cost schedule.
Do hot drops count as gate type?
Yes. Hot tip gates are a family with their own DFM page in the plan.
Does gate type affect resin degradation?
Small gates increase shear. Sensitive resins need sizing review.
Next step
Mark cosmetic faces before gate freeze
Upload CAD with gate witness constraints in notes.