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Undercuts

An undercut is any indentation or protrusion that prohibits an ejection of a part from a one-piece mold.

Typical undercuts

Below are 3 typical undercuts that are frequently seen in molded parts:

undercut-hole

holes

undercut-window

windows

undercut-clip

clips

Disadvantage of the undercuts

Adding cost to tooling and molding, as they make the molds and production complicated. For considering of cost-saving, you are recommended toto eliminate or minimize undercuts as possible.

Solutions of the undercuts

Here are three solutions to re-design of your parts to eliminate or minimize undercuts.

For holes

design guide for undertcut-2

For windows

design guide for undertcut-3

For clips

design guide for undercut-1

Notes: considering part functionality or geometry, undercuts are neccessary for some parts.

Undercuts not moldable

  • Some undercuts may not be moldable, which could be overlooked by designers.
  • If you are not sure about the undercuts for manufacturing, talk to Plastopia. We will analyze them and provide guideline to change the part design. Below are a couple of examples we help for our customers.
  • undercut injection muolded part
    undercut injection molded part
    injection molding undercut
    undercut injection molding
    undercut part design
    undercut injection moulding

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