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Mechanical Engineering vocabulary · Tolerances and Measurement

Surface finish

Meaning in mechanical engineering, with examples

nounCommon term

In mechanical engineering, surface finish means: How smooth or rough a surface is after it has been made, usually given as a roughness value such as Ra 1.6 µm.

In Turkish: yüzey kalitesi, yüzey pürüzlülüğü

How it is used

Used on drawings, in machining and in inspection. Engineers specify surface finish with a symbol on the drawing; machinists achieve it with the right tool, feed and speed. It is checked with a surface roughness tester.

Example sentences

  1. The seal running surface needs a surface finish of Ra 0.4 µm or better.

  2. Reduce the feed on the last pass to get a better surface finish.

Common collocations

  • surface finish requirement
  • smooth surface finish
  • surface roughness
  • Ra value
  • machined surface finish
  • machiningShaping a part by cutting away material with tools, for example by turning, milling, drilling or grinding, usually on a lathe or a CNC machine.
  • toleranceThe allowed amount of variation in a dimension or property, for example ±0.05 mm. A part is acceptable if its measured value falls inside this range.
  • millingA machining process in which a rotating cutting tool with several teeth removes material from a workpiece to make flat surfaces, slots, pockets and complex shapes.
  • sealA part that stops liquid, gas or dirt from leaking between two surfaces, especially where one part moves, such as a rotating shaft or a sliding piston rod.

More terms: Tolerances and Measurement

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