Below is a list of Broaching manufacturers from Warren, Michigan. Broaching is an efficient, cost effective method of precision machining that can be performed on an external surface (round, flat or contoured) or the internal part of a shape or form. It is considered a metal removal service, and almost any material, from ferrous and nonferrous metals to plastic materials and wood are able to be cut through broaching, although softer metals are by far the most common material.