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ISO/ TC 153/Working Group 1 is involved in writing international standards including actuator mounting and drive dimensions for interfacing with valves, primarily ISO 5210 and ISO 5211.

A question has arisen regarding the sizing of Keys & Keyways in this context. The 2017 edition of ISO 5211 no longer refers specifically to ISO/TR 773 (which is now obsolete), but now just says that “key dimensions shall comply with those given in national standards”.

Various National standards exist, including BS 4235, DIN 6885, DIN 6892 & ANSI B17.1
The question that has been asked by a UK BVAA member is:
“Which standards are being used nationally for sizing of keys since the withdrawal of ISO/TR 773?”
We would welcome any feedback from BVAA members before 14th May regarding the above