Frequently Asked Questions
The part number would be 248/20 which is a combination screw head 20MM 3/16 BSW.
Slip Type Expansion Couplings are available from 16mm through to 50mm.The part numbers of slip type expansion coupling are as follows:
16mm = 251/16
20mm = 251/20 *
25mm = 251/25 *
32mm = 251/32
40mm = 251/40 *
* = only available in Grey
Where long conduit runs are likely to be exposed to wide variations in temperature, it is recommended that expansion couplings be used at each join. It is not recommended that Slip Type Expansion Couplings be used where the conduit run is exposed to the weather. Standard colour is Grey (GY).
Dimension details are attached.
Yes the part number is 221/20
No, the largest rated version of a 438 extension socket is the 438/20 which is 20A.