Burr

Where it comes up

• Metal stampingShort- to medium-run stampings: brackets, clips, shields, and plates cut and formed from sheet or coil in a press.
• Production machining, turning, and sawingCNC milling, turning, and production sawing from bar, plate, castings, and forgings, from prototype to production.
• Screw machine productsTurned pins, fittings, shafts, and bushings made from bar stock on multi-spindle and Swiss screw machines at volume.

Related terms

Blank

A blank is the flat piece of sheet metal cut from coil or sheet before it is formed, drawn, or pierced. Blank size and nesting drive material usage, which is often the largest cost in a stamped part. Blanks are produced by blanking dies, shearing, or laser cutting.

Progressive die

A progressive die is a stamping die with a series of stations that pierce, form, and cut a part in sequence as a metal strip feeds through the press. One finished part drops with each stroke. It is the lowest piece-price option for high-volume small and medium stampings.

Tolerance

Tolerance is the total amount a dimension is allowed to vary from its nominal value, such as ±0.005 in (±0.13 mm). Tighter tolerances raise cost through slower processes, extra operations, and added inspection. Hold them only on features that affect fit or function.