ISO 236-1:1976

Overview

ISO 236-1:1976 - Hand reamers (first edition, 1976) specifies standardized dimensions and tolerances for hand reamers. The part focuses on dimensional data needed for design, manufacture, inspection and procurement of hand reamers and ensures interchangeability between metric and inch sizes. The standard presents three principal tables giving: preferred diameters in millimetres, preferred diameters in inches, and corresponding sizes and lengths set out as functions of diameter steps.

Key topics and technical requirements

• Dimension tables: Recommended nominal diameters and corresponding dimensional data are provided both in millimetres and in inches to support dual-unit manufacturing and conversion.
• Diameter steps and lengths: Sizes are grouped by diameter steps; corresponding overall and cutting-edge lengths (Z, Z1, Z2) are given so length tolerances remain consistent across metric and inch ranges.
• Tolerances:
  • Cutting diameter tolerance: specified as m6 for reamers supplied from stock.
  • Shank diameter tolerance: specified as h9 (shank diameter is identical to the cutting portion diameter per this Part).
  • Length tolerances: tabulated values define permissible variation for overall and cutting-edge lengths.
• Shank and drive: driving square dimensions follow ISO 237; shank diameters and recommended driving-square sizes are coordinated with that standard.
• Practical notes: the standard flags certain bracketed sizes to be avoided where possible and allows selection of alternate nominal lengths from adjacent ranges in special cases while retaining the same tolerances.

Applications and who uses it

ISO 236-1:1976 is used by:

• Tool manufacturers specifying and producing hand reamers to ensure dimensional conformity.
• Tool designers and engineering departments creating jigs, fixtures and tool-holding arrangements.
• Quality control and inspection teams verifying reamer diameters, shank fits and length tolerances.
• Purchasing and supply chain professionals sourcing standardized reamers for maintenance and production.
• Machine shops and maintenance workshops that require interchangeability between metric and inch reamers.

Typical applications include precision hole finishing in metalworking, maintenance tool kits, and production lines where consistent reamer sizing and fit to chucks or driving squares is essential.

Related standards

Referenced standards in ISO 236-1:1976 include:

• ISO 236/11 - Long fluted machine reamers (Morse taper shanks) (as cited in the document)
• ISO 237 - Diameters of shanks and sizes of driving squares for rotating tools with parallel shanks
• ISO 521 - Machine chucking reamers with parallel shanks or Morse taper shanks

Keywords: ISO 236-1:1976, hand reamers, reamer dimensions, reamer tolerances, shank diameter, cutting diameter, metric and inch sizes, tool interchangeability.