1- Surface Finish - 1: What is Surface Finish?
|A note before beginning. This topic is derived from Machinery's Handbook 26th edition. It will focus on the ANSI/ASME B46.1-1995 standard. There are other standards.
Surface finish is an apparent witness of tool marks or - lack of same - on the machined surface of a work piece. These two videos show fine, medium, and rough surface finishes for the lathe and the mill.
Surface finish is a characteristic of any machined surface. It is sometimes called surface texture or roughness. The design engineer is usually the person that decides what the surface finish of a work piece should be. They base their reasoning on what the work piece is supposed to do. Here are a few examples that the engineer considers when applying a surface finish spec:
The design engineer communicates their desires by using a blueprint. The blueprint is the communication medium that the machinist will use to make the work piece. The surface finish is defined and measured as a surface profile. The main components of a surface profile are waviness and roughness.