prBAS ISO 5686-3:2025

This document specifies the dimensions of couplings for driven tool holders with polygonal taper shanks with flat contact surface (PTI). These shanks are the tool-side part of the interface to the (in cutting process non-rotating) tool carrier of machine tools (e.g. turret lathes, turning centres). This document specifies a coupling type that applies to two of the three tool-side interface types defined in ISO 5686-1 (F, A). The tool shanks themselves are designed identically for all types. —     Shank type F has two holes for the coolant supply (F = fluid) on the face contact for use in two installation positions (offset by 180°). —     Shank type A has two holes on the face contact for the primary coolant supply and additional two holes for supplying the tool holder (driven tool) with sealing air (A = air). An installation position offset by 180° is possible. A spring-type straight pin belongs to the holder and avoids incorrect insertion.