A complete lapping kit which can be used on Tyco, Crosby and Anderson Greenwood Pressure Relief Valves.

The lapping blocks are double sided, one side HY iron for high removal rate and other side is HY copper for finishing /polishing. Each block has two perfectly flat working sides and it is crucial that the lapping blocks keep their high flatness to produce a flat seating surface on either the disc or the nozzle.