Features: brand new and high quality The screw tap tapping chuck are suitable for machine taps,use for wind batches, electric batches, electric drills, etc. The adapter square drive with built-in clamping clip,makes the tap die and socket adapter connection for stronger and not easy to fall. The tapping chuck for 1/4'' hex shank 1.5-16mm diameter meet the SPU:13AC19009same size machine tap, high concentric rate. Hex shank tap sockets are made of alloy steel with high hardness and high wear resistance. Widely used in mold manufacturing, pneumatic air batch, DIY, auto repair and other professional machine maintenance, etc. Specifications: Material:Alloy Steel+6542HSS Mixed Size Package Includes: 8 Pieces M4-M16 Tap Die Socket Adapters/Set note: Due to manual measurement, please allow 1-2mm error. Please make sure you don'for t mind before ordering. Due to the difference of different monitors, the picture may not reflect the actual color of the commodity.