Description | Richardson Electronics offers impeder mounting hardware, impeder testers and induction coils for your pipe welding operation, as well as high quality impeders for the pipe manufacturing industry. Impeder casings are available in the following materials: Epoxy Glass--Least expensive, most wear resistant material. Used when the impeder is not supported in the tube and is subject to mechanical wear. Magnetic Glass (Ferroglass)--A ferrite filled, epoxy glass material that has the effect of increasing the total mass of ferrite in the impeder. It also places the ferrite close to the weld point, resulting in up to a 50% speed increase with the same power. Silicon Glass (Silglass)--Consists of glass fibers bound in a silicone resin. Has the ability to withstand high temperatures for a long period.