Exhaust header flange nuts


Registered user
Sep 24, 2011
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West Yorkshire
Can anyone tell me what type these nuts are and perhaps where I might be able to get the right tool to remove them?


I'm so glad I checked this out before I started removing the system to find I didn't have the right tool!
You need Star Spanner’s - don’t use normal metric ones - buy a set from Halfords
But the Halfords set doesn’t have a “16”....🤔
But they do refunds on unused tools...
Ask me how I know 😂
Got a full set ordered from my local industrial suppliers.
Right I’ve just changed my headers, you need a 13mm multipoint socket or ring spanner, it’s a tight fit and I had to tap my socket on with a hammer, not hard just a tap.
Its a 13 metric , I have a picture of the socket , it was made by Zebra , has an unusual iternal pattern but you would get the idea on what to compare with.


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That’s the kiddie, I used a standard multipoint and it worked fine.
I am sure a Star socket or spanner is the preferred tool, but in all the years that I have had to deal with this type of nuts, a regular 12-point socket or spanner have always worked.

If this was my problem, unless a Star socket already was in my toolbox I would have given the regular tools a try.
Its already been said but a standard 13mm bi-hex socket or ring spanner is the right tool. No special tool required and don't let anyone tell you differently
Most of you guys are correct, the nuts are designed around a standard bi-hex socket.
The best one to use is a Snapon 13mm Flank drive semi deep as the socket fits perfectly on the nut & also thin walled so you won’t damage the exhaust or have to hammer it on.

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