ISO 10899:1996

Overview

ISO 10899:1996 specifies technical requirements for high-speed steel two‑flute twist drills with either cylindrical or Morse‑taper shanks. It covers dimensional tolerances, material and hardness requirements, surface finish, marking and test/measurement methods for drills used in metalworking (excluding roll‑forged drills and do‑it‑yourself/woodworking drills). The standard provides a consistent basis for purchasers and manufacturers to agree special‑purpose drill specifications.

Key Topics

• Scope and applicability: Two‑flute HSS twist drills (cylindrical or Morse taper shanks); not for roll‑forged or woodworking drills.
• Dimensions & tolerances: Drill diameter measured across lands; back taper permitted (typically 0.02%–0.08% over flute length; total back taper ≤0.25 mm; smaller diameters may be parallel). Overall and flute lengths follow relevant dimensional standards; length tolerances per ISO 2768-1.
• Radial runout: Tolerances calculated from a formula that depends on drill diameter and overall length (runout tolerance expressed as a base value plus a term proportional to L/d). No runout tolerance stated for drills d