Surface Roughness Conversion Chart

Surface Roughness Conversion PDF Download PDF
(size 99.7Kb)

The table below shows comparisons of various surface roughness scales. The information contained in the table is based on the assumption that metal surfaces are being tested. Comparison values may vary by up to 25%.

Surface Roughness Conversion Chart
Ra
(micrometers)
Ra
(microinches)
RMS CLA
(N)
Rt N Cut-off Length
inch mm
0.025 1 1.1 1 0.3 1 0.003 0.08
0.05 2 2.2 2 0.5 2 0.01 0.25
0.1 4 4.4 4 0.8 3 0.01 0.25
0.2 8 8.8 8 1.2 4 0.01 0.25
0.4 16 17.6 16 2 5 0.01 0.25
0.8 32 32.5 32 4 6 0.03 0.8
1.6 63 64.3 63 8 7 0.03 0.8
3.2 125 137.5 125 13 8 0.1 2.5
6.3 250 275 250 25 9 0.1 2.5
12.5 500 550 500 50 10 0.1 2.5
25 1000 1100 1000 100 11 0.3 8.0
50 2000 2200 2000 200 12 0.3 8.0

Ra = Roughness Average in micrometers or microinches
RMS = Root Mean Square in microinches
CLA = Center Line Average in microinches
Rt = Roughness Total in microns
N = New ISO (grade) scale numbers
Cut-off Length = Length required for sample

Request a Quote
© 2015 CAB Incorporated. All Rights Reserved.Site created by Thomas Web Solutions