ISO 19744:2020

Overview

ISO 19744:2020 - Test conditions for numerically controlled broaching machines - specifies how to verify the cutting accuracy of numerically controlled (NC) vertical surface type broaching machines. With reference to the ISO 230 series, it defines geometric and positioning tests, recommended test pieces (broached slots and grooves), and tolerances for machines of general purpose and normal accuracy. The standard focuses on verification of machine accuracy (not operational behaviour such as vibration or feeds/speeds) and gives terminology and axis designation aligned with ISO 841.

Key topics and requirements

• Geometric tests (reference: ISO 230-1):
  • Straightness, squareness and parallelism checks of linear motions.
  • Verification of rotary axis accuracy (if present) with reference to ISO 230-7.
• Positioning and repeatability (reference: ISO 230-2):
  • Positioning tests for NC linear and rotary axes, including accuracy and repeatability limits.
• Machining tests and test pieces:
  • Proposed test pieces containing broached slots and grooves for finishing-condition cutting tests.
  • Characteristics and dimensions of test pieces are specified to assess cutting accuracy.
• Tolerances and minimum requirements:
  • Establishes tolerance guidance for acceptance testing of vertical surface type broaching machines; minimum tolerance values are provided (example: minimum tolerance of 0.005 mm when scaling lengths).
• Terminology and axes designation:
  • Defines nomenclature for common NC vertical surface broaching configurations (A, B, C axes variants) used typically in turbine disk manufacture.
• Scope limits:
  • Does not cover operational testing (vibration, abnormal noise, stick–slip) or general machine characteristics such as speeds and feeds.

Applications and who uses it

• Machine tool manufacturers and suppliers - for design validation and factory acceptance testing of NC vertical surface broaching machines.
• Quality and inspection engineers - to perform acceptance, maintenance and periodic accuracy checks.
• Aerospace and power-generation manufacturers - especially producers of turbine disks where surface broaching is used to generate slots and grooves.
• Test laboratories and calibration facilities - to standardize measurement methods and test-piece usage.
• Procurement teams - to specify minimum accuracy and test requirements in purchase contracts.

Related standards

• ISO 230-1:2012 - Geometric accuracy (no-load/quasi-static).
• ISO 230-2:2014 - Positioning accuracy and repeatability of NC axes.
• ISO 230-7:2015 - Geometric accuracy of axes of rotation.
• ISO 841 - Axis designation and terminology.

Keywords: ISO 19744:2020, numerically controlled broaching machines, vertical surface type broaching machines, testing of accuracy, geometric tests, positioning tests, broaching, turbine disks, ISO 230.