Blanking & Piercing

Blanking and piercing shear flat sheet metal in a press to create outer profiles and holes fast, repeatably, and cost-effectively at production volumes.

Overview

Blanking cuts a 2D outline from sheet or coil; piercing punches holes or internal features. Both use a punch-and-die set in a stamping press to shear the material, producing high throughput, consistent features, and low piece-part cost once tooling is built.

Choose blanking & piercing for flat parts with tight hole-to-edge relationships, clean repeatability, and volumes that justify dedicated tooling (typically thousands+). It’s common as a stand-alone operation or as the first steps before forming.

Tradeoffs: upfront die cost and lead time, and geometry limits to 2D profiles with modest edge quality (shear/burr, rollover, breakout). Tolerances depend heavily on thickness, material, die clearances, and press rigidity; secondary ops (deburr, ream, coin) may be needed for burr control or tight hole size.

Common Materials

  • Low carbon steel
  • Stainless steel 304
  • Aluminum 5052
  • Aluminum 6061
  • Copper C110
  • Brass C260

Tolerances

±0.003" to ±0.010"

Applications

  • Electrical busbar blanks
  • Mounting brackets and plates
  • Motor lamination blanks
  • Gaskets and shims
  • Washer and spacer blanks
  • Connector and terminal blanks

When to Choose Blanking & Piercing

Choose blanking & piercing for flat sheet-metal parts where the primary requirements are outline accuracy, hole patterns, and high repeatability at production volumes. It fits best when features can be created by shearing (no 3D forming needed) and the cost model benefits from tooling amortization over many parts.

vs Progressive Die Stamping

Choose blanking & piercing when the part can be made in one or a few simple hits and doesn’t justify a multi-station progressive die. It’s a good fit for lower-to-mid volumes, larger/thicker parts that are hard to advance reliably, or when you want simpler tooling and faster die build.

vs Transfer Die Stamping

Choose blanking & piercing when the part remains flat and can be produced without transfer between stations. It avoids transfer fingers/automation complexity and is often cheaper when you only need a blank and holes rather than multiple forming stages.

vs Deep Drawing

Choose blanking & piercing when the end part is fundamentally a flat blank with cut features, not a cup or shell. It’s also the right choice when you need tight hole-to-edge relationships in 2D and want to avoid draw-related thinning, wrinkling, and shape control work.

vs Coining

Choose blanking & piercing when you need cut perimeters and hole patterns rather than localized high-pressure sizing, embossing, or very sharp feature definition. If edge condition is acceptable with normal shearing (and deburr if needed), blanking/piercing is typically faster and lower force than coining.

Design Considerations

  • Specify material, thickness, temper, and grain direction (if relevant) to lock in die clearance and burr behavior
  • Call out burr direction and allowable burr height; plan deburr/edge break if the part has handling or electrical contact requirements
  • Keep minimum hole diameter roughly ≥ material thickness and avoid skinny webs; use larger radii to reduce punch breakage
  • Maintain consistent hole-to-edge distance (rule of thumb ≥ 1× thickness) to reduce edge distortion and tearing risk
  • Use common punch sizes and standard radii where possible to reduce tooling cost and lead time
  • Dimension critical features from a consistent datum scheme and define whether dimensions apply before or after deburr/secondary ops