ISO 5734:1986

Overview - ISO 5734:1986 (Acceptance conditions of mechanical dividing heads for machine tools - Testing of accuracy)

ISO 5734:1986 specifies the geometrical tests and permissible deviations for general-purpose and normal-accuracy mechanical dividing heads used on machine tools. The standard is limited to verification of the device’s accuracy (dimensional and positional checks) and does not cover dynamic running tests, which should normally be checked before accuracy verification. ISO 5734 cross‑references ISO 230/1 for measuring methods and recommended testing equipment accuracy.

Key topics and technical requirements

• Scope of tests: Geometrical checks on spindle taper run-out, centre run-out, external register diameter run-out, periodic axial slip and camming of the spindle nose, squareness and parallelism, lateral offsets and dividing error of the transmission.
• Measurement methods and instruments: Use of dial gauges, test mandrels, reference plates and mandrels held between centres. Measuring lengths commonly referenced include 300 mm (12 in) and 12 mm/0.5 in in specific checks.
• Permissible deviations: Typical tolerance values given in the standard include 0.01 mm (0.0004 in) and 0.02 mm (0.0008 in) for many run‑out and axial measurements. The published minimum tolerance value to consider is 0.01 mm (0.0004 in). Angular dividing errors are expressed in arc minutes/seconds (examples in the standard: bands such as 1′30″ or 2′ of arc for certain tests).
• Specific checks highlighted:
  • Run-out of internal taper at mouth and at 300 mm from spindle nose.
  • Run-out of spindle centre and external register diameter; measurement of periodic axial slip and camming.
  • Squareness of spindle to supporting surface and verification of detent-pin locating positions.
  • Parallelism of locating tenon to spindle axis, parallelism to clamping surfaces, and lateral offset to central T‑slot.
  • Maximum permissible dividing error for output shaft rotation (full revolutions and chosen angles across quadrants), including reversal error.
• Test preparation: The sequence of geometrical tests is related to sub‑assemblies but may be applied in any order to ease instrument mounting. The manufacturer should specify test forces where relevant.

Practical applications and users

ISO 5734 is used for:

• Incoming inspection and acceptance testing of dividing heads by machine tool manufacturers and buyers.
• Quality assurance and calibration in manufacturing, toolrooms and metrology labs.
• Maintenance, repair and refurbishment checks to confirm restored accuracy.
• Specification of acceptance conditions in procurement and conformity documentation.

Primary users: machine tool manufacturers, metrology/QA engineers, toolroom technicians, purchasers and service/repair shops.

Related standards

• ISO 230/1 - Acceptance code for machine tools (geometrical accuracy and measurement methods) - referenced for measuring procedures and equipment accuracy.