Used for holding the jobs, spark erosion operation, right angle grinding & Light machining. Made from high quality alloy steel. Accuracy for Square ness, Flatness & Parallelism within 0.005mm. Jaw pressure on work piece is forward & downward for repeatable positioning & maximum holding power. All sides can be used as reference. Hardness - 60 ± 2 Rc & Tempered. “V” on moveable jaw for better gripping of round jobs.