ISO 522:1975

Overview

ISO 522:1975, "Special tolerances for reamers", defines how to specify special dimensional tolerances for the cutting diameter of hand and machine reamers when a tighter accuracy grade than the standard stock grade (m6) is required. First published in 1975, this International Standard replaces ISO Recommendation R 522‑1966 and is intended to give a consistent method for relating reamer dimensions to the required hole tolerance (IT grade).

Key topics and technical requirements

• Purpose: Specifies limits for the diameter of the cutting portion of reamers to produce holes with a given tolerance class (IT).