Well the progress of metrication in the UK has been long and slow, but as far as standards is concerned, imperial units (inches etc) has long gone.
I do not have access to this standard, but from the BSI website:
BS EN 3506-1 Is actually:
BS EN ISO 3506-1:2009 Mechanical properties of corrosion-resistant stainless steel fasteners. Bolts, screws and studs.
BS EN ISO 3506-1 specifies the mechanical properties of bolts, screws and studs made of austenitic, martensitic and ferritic steel grades of corrosion-resistant stainless steels, when tested over an ambient temperature range of 10 °C to 35 °C. Properties vary at higher or lower temperatures.
BS EN ISO 3506-1 applies to bolts, screws and studs
• With nominal thread diameter d u 39 mm,
• Of triangular ISO metric threads with diameters and pitches in accordance with ISO 68-1, ISO 261 and ISO 262, and
• Of any shape
The source of the standard can be found by taking the letter group in the standard in reverse:
ISO – This is the source of the standard
EN - (EuroNorm) European Standards authority, CEN-CENELEC, have a policy of adopting ISO standards
BS – British Standards have a policy of adopting EN standards
So where does this leave us, well since the UK finally agreed to formally adopt the SI system of measurement after joining the EU in 1973, then all future standards were metric and any imperial standards remaining were converted to metric. So, it is very unlikely that there is an ‘inch’ version of this standard, given that it has come from an international source. There may have been an earlier imperial standard, but the BSI site does not refer to this.
