Related Resources: manufacturing

How to use a Surface Roughness Comparator

Surface Roughness Review 
Surface Roughness Conversion Chart
Manufacturing Engineering Processes

Surface roughness comparators are used within industry to measure or verify the as-manufactured surface finish (roughness) of a part or assembly. Comparators are selected and used based on the manufacturing process used to create a particular surface finish. Industry standard manufacturing specific roughness comparators are available for the following processes:

Casting
Conventional Machining
Cylindrical Ground
Surface Turned
Electrical Discharge Machining EDM
Shot Blast
Grit Blast

Typical Casting Surface Roughness Comparator

Using a Surface Roughness (Finish) Comparator

1. Place the roughness scale next to the work piece.
2. Slide the various scales next to each other so that the comparator scale area is adjacent to the surface you are measuring.
3. Compare by drawing your fingernail across each surface at right angles to the tool marks.
4. When the feel at the finger nail contact is the same or close then the finish (roughness) is identical.
5. If an exact match cannot be found then the measured surface roughness is reported as the next higher roughness comparator scale.