Surface Roughness Of Steel Sheet

Steel surface finishes are often an important aspect of custom machine parts.

Surface roughness of steel sheet.

Galvanized steel most common material used in fabricated duct work for most comfort air conditioning systems. If these deviations are great the surface is rough if they are small the surface is smooth. The roughness as measured using a profilometer is approximately 35 to 65. Typical ra would be 0 30 0 50 µm 12 20 µin.

R relative roughness. Relative roughness can be expressed as. It is quantified by the vertical deviations of a real surface from its ideal form. 2b mill finishis a bright defect free finish that is produced by a final light cold roll pass on polished rolls.

Values of about 70. R k d h 1 where. Surface consistency is key to this type of finish. Typical ra would be 3 50 7 50 µm 140 300 µin.

In practice it is often necessary to know both the ampli tude and frequency to ensure that a surface is fit for purpose 1. The level of the grit impacts the surface roughness which is typically measured in terms of micro inches or micro meters represented as ra roughness average. There is no visible figrainfl with this finish. Surface roughness is a measure of the texture of a surface.

With this steel surface roughness 653 ra range the stochastic surfaces shot blast and edt show much lower a i. However common applications of this stainless steel surface finish involve non decorative purposes. Regular matte this finish is widely used for most applications of cold rolled steel sheet. Roughness is typically considered to be the high frequency short wavelength component of a measured surface.

The finish provides a uniform dull surface that is suitable for painting and lacquering. The surface finish of a machine part may be important to reduce friction with other machine parts or to improve the aesthetics of the part. Two materials shot blast and edt with extreme ra level 3 01am used in sanitary applications are tested as a reference. The resulting surface is slightly coarse with very low reflectivity and a typical average roughness ra between 4 7 micrometers.

The higher the grit numbers the finer the polishing lines and more reflective the finish. K roughness of duct pipe or tube surface m ft d h hydraulic diameter m ft typical duct materials and their use. Sometimes steel surface finish is also referred to as surface texture or surface roughness.