ISO 3442-2:2005

Overview

ISO 3442-2:2005 - Machine tools - Dimensions and geometric tests for self-centring chucks with two-piece jaws - Part 2 covers power‑operated, self‑centring chucks with tongue‑and‑groove (two‑piece) jaws. The standard specifies sizes for interchangeability, the geometric tests (by reference to ISO 230-1) used to verify chuck geometry and rotational accuracy, and the tolerances that apply to those tests. All dimensions and tolerances are given in millimetres (mm).

Key Topics and Requirements

• Scope: Verification focuses on rotational accuracy of the chuck and position of top‑jaw assembling elements. The standard explicitly does not cover dynamic aspects such as balancing, gripping power or balancing procedures.
• Interchangeability sizes: Nominal chuck diameters covered include typical sizes from 100 mm to 800 mm (see the standard’s Table 1 for full dimensions and mounting/thread details).
• Referenced test code: Geometric tests are described by reference to ISO 230-1:1996 (Test code for machine tools - geometric accuracy).
• Geometric tests (G01–G05):
  • G01 / G02 - Checking spindle/face-plate radial run‑out and camming (tolerance 0.005 mm).
  • G1 / G2 - Radial run‑out of outer surface and camming of chuck face (tolerances vary by nominal diameter: 0.02–0.06 mm depending on size band).
  • G3 - Equidistance between top jaw locating key slots (0.03–0.12 mm).
  • G4 - Deviation between top of master jaws and mounting chuck face (0.03–0.10 mm).
  • G5 - Deviation between top jaw locating centre‑line and a parallel plane through chuck centre‑line (0.05–0.20 mm).
• Measurement practice:
  • Primary instrument: dial gauge.
  • Tests may be performed with the chuck mounted on a test spindle or using a measuring machine; results can differ due to spindle‑nose tolerances.
  • Several tests require the chuck tightened with base/master jaws locked on a dummy piece and clamping force as specified by the manufacturer.
• Accuracy class: The document specifies a single accuracy class; specially adjusted non‑interchangeable jaws must be marked.

Applications and Users

• Who uses it: machine‑tool manufacturers, chuck designers and manufacturers, QA/metrology labs, maintenance teams, and procurement/specification engineers.
• Practical uses:
  • Ensuring interchangeability of top jaws between chucks.
  • Specifying acceptance criteria for incoming chucks and routine quality checks.
  • Supporting accurate jaw mounting and pre‑setting on jigs separate from the machine spindle to maintain machining precision.

Related Standards

• ISO 230-1:1996 - Test code for machine tools (geometric accuracy)
• ISO 1101 - Geometrical product specifications (GPS)
• Other parts of ISO 3442:
  • Part 1: Manually operated chucks with tongue and groove jaws
  • Part 3: Power‑operated chucks with serrated jaws

Keywords: ISO 3442-2:2005, self‑centring chucks, power‑operated chucks, tongue and groove jaws, geometric tests, interchangeability, machine tools, tolerances, dial gauge.