Dura-Bond’s patented materials and processing of powder metal valve seats offer excellent machinability, along with low wear and high heat resistance. These inserts have finely dispersed tungsten carbide residing in a matrix of tempered tool steel and special alloy iron particles to provide all the properties an application requires. The 30000 series is intended for the light to medium duty range. This very machinable exhaust seat material is designed for unleaded fuels.