seat belt/harness anchorage?
 

evening all,

is there anything wrong with using m12 captives rather than 7/16ths stated in the book, had a quick gander at the iva manual thinggy and cant find anything relating to the thread or size of the bolt, what would you guys suggest?

Ta Very Much

JakeH

7/16th is standard for seatbelt mounting bolts. Why do you want to use M12s?

just what iv got lying around, do you have to use specific bolts for the mounting points then? i know that seatbelt bolts are usually a coppery colour.

Ta Very Much

JakeH

Just high tensile ones. 8.8 or higher. Not sure about the thread though personally, which is why i went with the 7/16s

7/16 UNF(unified national fine) is the standard used.This is obviously a fine thread.You can also get UNC(unified coarse).There is a genuine reason for using a fine thread although i cant remember what it is/was.:eek:
Personally i would go for the 7/16 UNF or if you cant get them then go for M12 in a fine pitch,M12 by 1.50 pitch as opposed to the standard M12 by 1.75.Although probably easier to get the UNF thread than a metric fine.;)(8.8 tensile strength or 12.9)

Most belts are supplied with fittings and they are always 7/16unf

Ozzy
its something to do with fine threads are stronger and less likely to shear
its one of those clever/silly/nerdy techno equation things like shear stress and tensile strength stuff.
But 7/16 unf is not compulsory for iva you just have to have alternative fixings of adequate/ equal strength to 7/16 unf
But it is really easy to get hold a tap and the right drill bit for 7/16 unf
choice as they say is yours :D
HTH les g

Finer threads = more surface area = stronger.

TT

Makes lots of sense Les,every pitch is a potential fracture and the finer the better in engineering terms.

That and for some odd reason belt firms still supply belts with 7/16 unf fittings rather than foreign millymetric stuff:)