New Body is made of mild steel. Jaws are made of Alloy Steel Grade EN31 The Jaws are hardened & Ground. Used for threading a drilled hole at a machine location, without actually moving the work piece. Tapping accessory for drill presses & lathes. Ensures identical center line of the tap & the drilled hole. Capacity 1/16 to 1/4 ( 1.5 to 6 mm) Capacity 1/4 to 1/2 (6 to 12 mm) SET OF 2 PIECE