Chatter

Where it comes up

• 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

Surface roughness (Ra)

Surface roughness (Ra) is the arithmetic average of a surface profile's deviations from its mean line, reported in microinches or micrometers. Typical machined surfaces run 63–125 µin (1.6–3.2 µm) Ra, ground surfaces 16–32 µin (0.4–0.8 µm), and seal surfaces often 16 µin (0.4 µm) or finer.

Fixture

A fixture is a custom workholding device that locates and clamps a part in a repeatable position for machining, welding, assembly, or inspection. Good fixtures locate from the drawing's datums. Fixture cost is usually a one-time charge on the quote, separate from piece price.

CNC

CNC is computer numerical control, the use of programmed instructions to drive machine tool motion. CNC mills and lathes cut parts from solid stock to typical tolerances of ±0.005 in (±0.13 mm), and ±0.0005 in (±0.013 mm) on critical features. It suits prototypes and low-to-medium production.