Correct** S55 M3 M4 tool/socket Spark Plug DIY

[overlook637]

The Schawben thin wall will still stick on the side and your extension will come off first. Leaving the socket down in the hole. I used my grinder to take off maybe .3mm from the height, chamfered the top edge. After the adjustment it would come off. Alternative option is to use a stiff extension or some tape on the extension to make it tighter on the socket.

Plus I noticed two chunks of metal had broken off from the inside of the socket.