This document specifies the dimensions of 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 three types of tool-side interface types, which differ at the face contact. 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 H has a primary coolant hole for the main supply and a secondary coolant hole for an intermediate tool position on the face contact (H = half). For PTI type H holders an installation position offset by 180° is not possible.

—     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.