Author Topic: Thread - seat belt bolts.  (Read 2588 times)

0 Members and 1 Guest are viewing this topic.

Bambino126

  • Super Member
  • ***
  • Posts: 364
  • Karma: 3
  • Location: Staines UK
Thread - seat belt bolts.
« on: February 21, 2014, 10:24:41 AM »
Does anyone know what is the correct thread of the bolts that secure the seat belt mountings in the BIS?
Many thanks.

andyzeetec

  • Subscribers
  • Super Member
  • ****
  • Posts: 533
  • Karma: 5
  • 126 BIS
  • Location: East Sussex, Uk
Re: Thread - seat belt bolts.
« Reply #1 on: February 24, 2014, 05:24:42 PM »
Bit of an odd one, they measure 11mm O/D and it's a fine thread, so that's telling me it's not metric.

Top of the bolt head sais..

3F
8.8

Maybe someone else can help   :headscratch:


jokke

  • Super Member
  • ***
  • Posts: 157
  • Karma: 1
Re: Thread - seat belt bolts.
« Reply #2 on: February 24, 2014, 05:40:56 PM »
I think it is 7/16" UNF.
1980 Mazda RX626
1985 Mazda RX7
1998 Fiat 126p V6

andyzeetec

  • Subscribers
  • Super Member
  • ****
  • Posts: 533
  • Karma: 5
  • 126 BIS
  • Location: East Sussex, Uk
Re: Thread - seat belt bolts.
« Reply #3 on: February 24, 2014, 06:12:18 PM »
I think it is 7/16" UNF.

I reckon your probably right there.

The head stamps are to do with the manufacturer and strength of bolt which makes sense as it's for a seatbelt.

Bambino126

  • Super Member
  • ***
  • Posts: 364
  • Karma: 3
  • Location: Staines UK
Re: Thread - seat belt bolts.
« Reply #4 on: March 01, 2014, 02:09:06 PM »
It seems to be M11 x 1.25.

I can't think that an 80's Fiat would be using Imperial bolts?

Bambino126

  • Super Member
  • ***
  • Posts: 364
  • Karma: 3
  • Location: Staines UK
Re: Thread - seat belt bolts.
« Reply #5 on: March 01, 2014, 02:12:26 PM »
Bought  a "second tap" to clean up the threaded hole and also a "die nut" to clean up the bolt. Goes in and out smoothly now.
The tool shop man said the thread was M11 and "Metric-Fine". Quite a rare one!