All working parts precision ground and hardened. Completely sealed for maintenance free operation! Turning: The unequaled rigidity of this toolpost and holders insure smoother turning without chatter or vibration! Drilling: Set enables you to drill by power feed with your carriage, instead of hand operation or tailstock.T he tool (SBHA) can be used on straight shank, for example. Boing bar, u drill, twist drill, center drill and extension rod. Eg: SBHA 20-25 25mm: shank OD.