HSS Tool Set For Female Threads, 6 Pcs

HSS boring tool set, 6 pieces. One each cutter for 60 degree (metric) and 55 degree (Whitworth) inside threads, 1.3mm - 2.65mm and 4mm. Shaft of ? 6mm. Length 95mm. The cutters are held by a tool holder that mounts to the tool post of the PD 230/E. Comes in a wooden box.