Accusize Tools Mini lathe tool holders and boring bar sets are for lathe work use, fit OXA quick change tool post. It is a set of indexable tools with carbide inserts for cutting steel, metalworking. Specially designed for 7″ x 12″ mini-lathe. Use carbide inserts TCMT21.5. Each set includes 1 pc of each STJCR, STACR, STECN, STDCR tool holder and 1 pc of the boring bar S-STFCR, 1 trox key + 5 ps extra spare screws inserts TCMT21.5 installed on each of these tool holders. Packed in quality storage case. “4+1″ pcs mini tool holder and boring bar set TCMT21.5 Insert Versatile and economical. Screw Size: M2.5x 6 STJCR06-2, STACR06-2, STECN06-2, STDCR06-2, S06H-STFCR2 Packed in quality storage case.