Finding information on the correct ASME specifications for flange surface finishes is easy enough, but how do you actually machine the correct flange surface finish you need?
The principle of surface finishes for flanges facing is easy enough to understand and is simply determined by the depth of cut, the feed rate and the nose profile of the cutting tool.
Let’s assume you want to create a stock finish on a raised face flange that’s positioned in a vertical orientation.
To do this you will need a flange facing machine, which are available as internal and external mount versions and in a number of different sizes. In most situations a pneumatically powered machine will be the most appropriate option, but hydraulically powered versions are available too.