Subland twist drills with Morse taper shanks for holes prior to tapping screw threads

This standard specifies the technical requirements for Morse taper shank step twist drills designed to be used after a pilot hole has been drilled prior to tapping operations. It defines the dimensional characteristics and geometric tolerances necessary to ensure compatibility with standard tapping procedures. The document covers the overall length, diameter progression across the step sections, and the specific geometry of the cutting edges. Attention is given to the taper interface dimensions to guarantee secure mounting in compatible machine spindles and tool holders. The text outlines the criteria for the drill point angle and the clearance angles required for efficient material removal. It also includes provisions for the marking of identification data on the shank area. These specifications facilitate interchangeability between different manufacturers and users within the global market. The guidelines aim to streamline the manufacturing process for fastening components by ensuring consistent performance across various applications. Compliance with these parameters helps maintain quality in industrial machining environments where precision is critical for assembly integrity.