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Seat Belt Bolt Size 9 years 6 months ago #150842

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Bob
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Does anyone know what the thread size on the seat belt reel bolt?
The head is a 50 torx but I have no idea on the bolt type or the pitch of the thread.I need a longer bolt so I can fit my Xpower roll hoops.Any help would be most welcome.
Here's a photo of the original next to the replacement needed to fit the hoops.

Ta Bob.

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Seat Belt Bolt Size 9 years 6 months ago #150844

David Aiketgate
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David
mgf mk2 freestyle mpi 16" wheels, in Anthracite.
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I've had a look in my parts pile. I was sure I had one of those bolts, but no... The only one I could find was the one that attaches the seat belt buckle. That is M12x1.25

David

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Seat Belt Bolt Size 9 years 6 months ago #150846

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Bob
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Thanks David I've tried that size and it's just slightly too big.I suspect it's a UNF Thread.
I'm taking the original bolt to an engineer friend tomorrow he should be able to source me two bolts.If I get the size off him I'll post here for future reference.

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Seat Belt Bolt Size 9 years 6 months ago #150852

Plezier
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I very much doubt it's UNF as they were all metric by the time the MGF's were manufactured. Chances are it's a different pitch. Too dark now but will check in the morning. Hmmm now where are my thread pitch gauges?????

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Seat Belt Bolt Size 9 years 6 months ago #150854

mgtfbluestreak
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i bought myself a small pitch gauge off ebay about £3.comes in handy to find your exact pitch.........

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Seat Belt Bolt Size 9 years 6 months ago #150883

bryan young
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I fitted my Mike Satur Boxer hoops with the existing seat belt reel bolts, mine appeared longer than the one in your photo, i am also sure that the head size was T55 not 50, the 50 was loose in the head of the bolt, use the correct bolts as i think they are hardened.
:oops:

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Seat Belt Bolt Size 9 years 6 months ago #151134

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Bob
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Thanks for all the comments and help.

I've got some 7/16 UNF bolts from my friend and they do fit but seem slightly loose so I assume they are the wrong bolts.
It could be because there is no thread lock on them but I cannot risk using them.

I may have to contact Rimmers or maybe Mike Satur for help in the matter.

The photo below shows the original bolt on the left and the 7/16 UNF on the right.

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Seat Belt Bolt Size 9 years 6 months ago #151135

Fatbaldingoldgit
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7/16" UNF is dimensionally very close to an M12 x 1.25 both in TPI and overall diameter...

"You can’t be a real country unless you have a beer and an airline – it helps if you have some kind of football team, or some nuclear weapons but at the very least you need a beer"
- Frank Zappa

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Seat Belt Bolt Size 9 years 6 months ago #151136

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Bob
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Fatbaldingoldgit wrote: wrote:
7/16" UNF is dimensionally very close to an M12 x 1.25 both in TPI and overall diameter...

You're right there isn't that much in it but the M12 x 1.25 just wont fit, it's too big to go in, I've tried.

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Seat Belt Bolt Size 9 years 5 months ago #152098

David Aiketgate
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To update the information. As I had the car's engine access open I extracted a bolt from the seat belt fixing and measured the thread. It was definitely M12x1.25. :yesnod: