Metal Patternmaker how-to

How to Choose a Parting Line

Parting lines affect molding.

Updated By the Career Education Institute Curriculum Team
Quick answer

Parting lines affect molding. In short: study; find; minimize, then complete the remaining steps below.

Step by step

  1. Study the shape.

  2. Find the widest section.

  3. Minimize cores.

  4. Avoid undercuts.

  5. Mark the line.

  6. Confirm with the foundry.

Safety reminders for metal patternmakers

  • Follow machine safety
  • Ventilate resins
  • Wear PPE
  • Use dust collection

Pattern · Draft · Shrink allowance · Core box · Match plate · Parting line: see the full metal patternmaker glossary.

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