I need some M11 extra fine thread bolts and nuts to fit a seatbelt (to match the fittings already in situ)

I’ve been searching high and low online, I can find loads of tap and die sets, but no bolts or nuts (apart from one manufacturer who is charging over £9 per nut, and they are stainless so not strong enough!

Surely if people are buying tap and die’s, it must be a common size?!

Can’t even get parts from the dealer as I need longer fittings than standard…

Seatbelts are usually 7/16″ x 20 (UNF) which look like M11 but aren’t. They are readily available

Excellent, thanks!

Also try namrick in Hove, just about every bolt type under the sun.

Thanks Mr Ming

You may need to use a specific grade of bolt for the seatbelts (8.8 or better, perhaps). It concerns me sightly that you are also after nuts which implies that you aren’t fitting the belts to the manufacturer’s mounting points.

There’s a whole load of rules to follow if you want seatbelt mounting points to pass an MOT (or, more importantly, work when it matters).

Appendix 1 of this guidance will give you a flavour, but I don’t know if it’s directly relevant to your situation / still current:

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/210809/changes-to-seatbelt-installations-guide.pdf

Thanks Tilly, already familiar with that document as I referred to it when fitting a double seat in the back 🙂 However it’s not so useful for seatbelts themselves, it seems they make the assumption that most seats will have integral belts so there is not much on attachments to the vehicle structure itself.

I’m confident that the way I’m going to mount the belt is the strongest method. Have found a section of C Pillar that has two layers of metal, and I’ll be fitting anti crush tubes between the layers. The reel is being bolted to a load restraint point which looks as thick as the driver’s seatbelt point, and the end of the seatbelt will either have a 100x100x5 spreader plate under the floor, or bolted to a spare seatbelt point on the double seat.

It’s already a bit OTT to be honest, it’s probably going to get used once a year as it’s the 4th seat.