Surface Roughness Conversion Charts and Tables, definitions and data. Where: Ra = Roughness, average in micro-meters & micro-inches, RMS = Root Mean Square in micro-inches, CLA = Center Line average in micro-inches

Surface Roughness Chart. The machining surface finish chart offers important guidelines for measuring standard surface finish parameters. Manufacturers always use it as a reference material to ensure quality in the manufacturing process.

Introducing the machining surface finish chart, conversion, comparator photos, method, finish degree, Ra, Rz, RMS for iron and steel castings by Dandong Foundry in China.

RMS = Root Mean Square in microinches. CLA = Center Line Average in microinches. N = New ISO (grade) scale numbers. Cut-off Length = Length required for sample.

grit usa common [usa] ra e/p range [uk] ra rmax [japan] rmax approx. rms iso astm std japanese no. finish # name microinch ra microinch micron microinch micron microinch number ra microinch standard 2000 50 7875 200 n12 1000 25 3940 100 n11 500 12.5 1968 50 n10 60 #1 mill plate 250 50 max. 8.3 985 25 n9 140 max. 125 3.2 492 12.5 n8

Jan 12, 2022 · Surface finish charts help to understand materials’ surface parameters effectively, be it smooth or rough surfaces. This will help designers and manufacturers select surface finishing techniques that are most effective for products.

In the chart below, you can find the lowest surface roughness (best surface finish) that the main machining processes can achieve. Machining Process Ra [ Micro Inches ]

Additionally, manufacturers can use the Surface Finish Conversion Chart to compare different roughness scales for manufacturing processes. The table below converts surface finish or roughness between Ra, Rz, and RMS indicators.

• RMS: defined as Root Mean Square roughness, this method measures a sample for peaks and valleys. Lower numbers indicate a smoother finish • Ra: Known as the arithmetic mean, this measurement represents the average of all peaks and valleys.

Our surface comparison chart has been compiled for your convenience from numerous resources, for the purpose of allowing easy conversion between various systems.