Every treated surface has a certain roughness. The term roughness (or surface roughness) indicates the degree of unevenness of a surface. The lower the degree of roughness, the smoother the surface. A low degree of roughness increases the life span of a component: there is less wear as a result of slack or friction and the chance that irregularities will develop into a break is smaller.
EDM: low roughnesses
Using EDM, very low degrees of roughness can be achieved. The size of the spark used in EDM can be accurately specified and the smaller the spark, the smoother the result. At Ter Hoek, under certain conditions, a minimum roughness of 0.06 Ra* is feasible.
*Roughness is indicated in various roughness designations, including Rt, Rz and Ra. The roughness designation Ra measures the average deviation compared to the average profile.
In addition to roughness, the heat-affected zone also plays a role in the life span of a piece. When a workpiece is heated during processing and then cools down again, this can cause micro cracks. Thanks to an exceptional control over the process, at Ter Hoek we keep the heat-affected zone to a minimum. In combination with the appropriate post-processing, we can even completely eliminate the development of micro cracks.