A problem with a monster..

[Athame57]

I have an Oxford Monster lock & Chain, but lately the key is sometimes really difficult to turn and I get worried it might snap in there, it'll be the hell of a job on my hands. I've tried WD40 and oil but they don't help much. Said lock and chain is to meet an insurance requirement, it's only 15 months old, I don't want to be buying new ones yet....any suggestions?

[K2-K6]

Usually graphite is first call for lock internals.

Sand paper and a pencil core will get you graphite powder.  Won't hurt if WD already in there just sloosh the graphite in with more of it, or rinse it out first with isopropyl alcohol that you can usually get at chemist counter.

[Athame57]

Thanks K2-K6, I'll give it a go tomorrow!

[petermigreen]

I'd recommend white grease for locks as I've had good results with it myself.

Halfords do it in aerosol form also toolstation etc.

https://www.halfords.com/motoring/engine-oils-fluids/grease/comma-white-grease-500ml