There are many common blade adapters I use listed here.
Sometimes they are also called blade boss too!
Please note all parts listed are personally picked and I have gone to the trouble of only selecting genuine parts where possible.
Be sure to buy the correct one if your lawnmower has a self-drive belt as there are usually 2 types.
The most common blade adapters for Briggs And Stratton Crankshafts are very common.
The regular blade adapter found on many non-self-drive Mountfield, sovereign, Champion lawnmowers etc is Genuine Mountfield Petrol Push Lawnmower Blade Boss Kit fits HP185 (Screwfix) HP164, HP46, HP474,HP454, HP180
The most common blade adapter I replace for a self-driven lawnmower is Mountfield Genuine Stiga Twinclip Lawnmower 22.2mm Blade Boss 122465638/1
Leave me a comment on my Youtube channel if you can’t find a part. Just post your question on the comments section of any video and I will get back to you.
You can find my channel here https://www.youtube.com/c/MowerMan