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AXIOMMOLDS

Trimming Pins for Die Casting (Burr Cutting)

In-mold flash trimming pins that cut excess metal during the ejection stroke. Eliminates separate deburring operations and reduces per-part cost for high-volume die casting production.

Decision rule: In-mold trimming is cost-effective when flash thickness is ≤0.3 mm and the trim line follows a simple geometry. For thicker flash or complex contours, post-mold deburring may be more reliable. For detailed guidance, see our How In-Mold Trimming Works with Burr Cutting Pins.

Products in This Category

Burr Cutting Pins for Die Cast Trimming

Hardened tool steel. Shears parting line flash up to 0.5 mm during ejector stroke.

How In-Mold Trimming Works

Burr cutting pins integrate flash removal directly into the casting cycle:

  1. Metal injection: Molten metal fills the cavity. Thin flash forms at the parting line gap (typically 0.1–0.5 mm).
  2. Solidification: Metal solidifies. Flash remains attached to the part at the parting line.
  3. Ejection + trimming: The ejector plate advances. The burr cutting pin — positioned at the flash location — advances through the solidified flash, shearing it against a hardened counter-edge in the fixed mold half.
  4. Mold opening: Trimmed flash falls free. Part exits with minimal residual burr (<0.1 mm).

Decision rule: In-mold trimming is cost-effective when flash thickness is ≤0.3 mm and the trim line follows a simple geometry. For thicker flash or complex contours, post-mold deburring may be more reliable. For detailed guidance, see our How In-Mold Trimming Works with Burr Cutting Pins.

When to Use In-Mold Trimming

✅

Best Suited For

High-volume production (>50K parts/year) where post-mold deburring labor exceeds $0.05/part. Consistent flash locations along straight parting lines. Flash thickness ≤ 0.5 mm.

The precision cutting edge shears flash during the ejection stroke at controlled blade clearance (0.02-0.05 mm), producing a clean trim that eliminates secondary deburring labor.

Recommended: Standard Burr Cutting Pin for flash ≤0.3 mm

⚠️

Not Recommended For

Complex 3D parting lines, flash thickness > 0.5 mm (fix root cause instead), or cosmetic surfaces where any pin mark is unacceptable.

The precision cutting edge shears flash during the ejection stroke at controlled blade clearance (0.02-0.05 mm), producing a clean trim that eliminates secondary deburring labor.

Recommended: Standard Burr Cutting Pin for flash ≤0.3 mm

Decision rule: In-mold trimming eliminates a separate deburring station — reducing per-part handling cost by 15–30% on high-volume runs where the trim geometry is compatible with pin-based cutting. For detailed guidance, see our In-Mold Trimming vs Post-Mold Deburring — Cost Comparison.

Frequently Asked Questions

How do burr cutting pins trim flash inside the mold during the casting cycle?+
Burr cutting pins operate during the ejection stroke. The pin has a precision-ground cutting edge that shears flash as the ejector plate advances. The cutting action occurs at the parting line or at overflow/vent locations where flash forms. The pin first contacts and shears the flash, then continues forward to eject the trimmed casting. This eliminates the flash as an integral part of the casting cycle, removing the need for a separate secondary trimming operation.
What flash thickness can burr cutting pins handle?+
Standard burr cutting pins handle flash thickness up to 0.5 mm — this covers most controlled die casting processes. For flash exceeding 0.5 mm, the shearing force increases rapidly and can cause pin deflection or premature edge wear. If your process consistently produces flash thicker than 0.5 mm, address the root cause (worn die faces, insufficient clamp tonnage, thermal distortion) rather than relying on thicker burr cutting pins. The cutting edge typically requires re-grinding or replacement every 30,000–50,000 shots.
In-mold trimming vs post-mold deburring — which saves more cost?+
In-mold trimming with burr cutting pins saves 15–30% of total per-part finishing cost for high-volume production (>50,000 parts/year). The savings come from eliminating a secondary trimming station, reducing labor, and avoiding trim die tooling investment. However, burr cutting pins increase mold complexity and maintenance cost. The breakeven point is typically around 30,000–50,000 annual parts. Below that volume, post-mold deburring with manual trimming or a trim press is more economical.

Engineering Resources

Technical Guide

How In-Mold Trimming Works with Burr Cutting Pins

Detailed mechanism, pin positioning, and counter-edge design for effective in-mold flash removal.

Cost Analysis

In-Mold Trimming vs Post-Mold Deburring — Cost Comparison

Break-even analysis for in-mold trimming adoption at different production volumes.

Need Burr Cutting Pins?

Send your parting line drawing and flash locations. We will recommend pin positioning and quantity.

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✓ 100K–200K shot life✓ MOQ 1 piece