This standard BS EN ISO 5821:2009 Resistance welding. Spot welding electrode caps is classified in these ICS categories:
25.160.30 Welding equipment
This International Standard specifies the dimensions and tolerances of resistance spot welding electrode caps, where a female taper (see ISO 1089) is used to fix the cap to an electrode adaptor (see ISO 5183-1 and ISO 5183-2).
It applies only to electrode caps for which the electrode force, FE, given for diameter d1 in Table 2 and Table A.2 is not exceeded.