Overview
ISO 865:1981 - "Slots in platens for projection welding machines" is an International Standard that specifies dimensional and positional requirements for T‑slots in platens used on projection (resistance) welding machines. Published in 1981 by ISO/TC 44 (Welding and allied processes), it cancels and revises ISO Recommendation R 865‑1968. The standard ensures consistent slot geometry, pitch and location so platens, clamps and fixtures are compatible across machines and tooling.
Key topics and requirements
- Scope: Requirements for dimensions, pitch and location of T‑slots on platens for projection welding machines (resistance welding).
- Slot dimensions: A table in the standard gives specific dimensional values in millimetres for T‑slots, differentiated by electrode force categories (notably for machines below and above 5 kN). Where special circumstances require other sizes, ISO 299 (Machine tool tables - T‑slots and corresponding bolts) is the reference for alternative dimensions.
- Pitch: T‑slot pitch is specified as 63 ± 0.5 mm. The tolerance of the total distance between any two T‑slots (regardless of the number of slots between them) is +0.5 mm.
- Number and arrangement: The number of T‑slots in a platen shall be even. Exception: small machines (maximum force ≤ 5 kN) may use an odd number of slots if the central slot lies on the platen centre line.
- Orientation: The lower slot shall be positioned at 90° relative to the upper slot. It is recommended that upper slots be parallel to the throat of the machine.
- Designation: A platen is designated by ISO 865 followed by the number of slots (e.g., Platen ISO 865‑4 for four T‑slots).
Applications and users
ISO 865 is directly useful for:
- Welding machine manufacturers - designing platens and standardizing accessory interfaces.
- Fixture and tooling designers - creating clamps, dies and jigs that fit platens reliably.
- Maintenance and retrofit teams - replacing or upgrading platens and tooling with interoperable components.
- Quality and compliance engineers - verifying platen geometry and adherence to international standards.
Practical benefits include improved interchangeability of tooling, predictable clamping performance, and simplified machine integration.
Related standards
- ISO 299 - Machine tool tables - T‑slots and corresponding bolts (referenced for alternative slot sizes).
- ISO 865 replaces ISO Recommendation R 865‑1968.
Keywords: ISO 865:1981, T‑slots, platens, projection welding machines, resistance welding, slot pitch, platen dimensions, welding fixtures, ISO standard.