Asking for a friend who just moved from the US to the UK: is there a UK equivalent of McMaster-Carr?
Nothing comparable in scope, no. But there are local retailers that carry a good range of engineering supplies. What are they looking for - hardware, bearings, materials, tools, consumables? I’m sure we can come up with a list of alternatives.
RS Components has a good selection of stuff. Website is not as optimized as McMaster, and selection might be a little more limited. But easy transactions and you get stuff next day.