18 replies to this topic

[Spider]

Bit off topic but interesting nevertheless.

 

Is it worth making a sticky topic regarding stainless bolts of prevent misinformation being dispersed?

 

Someone probably should do a write up on fasteners, including Stainless and High Tensile and why they are not always the most suitable for every job. Fasteners are, after all, some of the 'glue' that holds our cars together   

 

IMPERIAL HEAD MARKINGS

 

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These are most commonly available in Grade 2, Grade 3, Grade 5 and Grade 8. Some of the Cap Head Fasteners go to Grade 10 and Grade 12. Numbers like 4.8 and 8.8 are not used on Imperial fasteners, they are for those below

 

 

 

METRIC HEAD MARKINGS

[tiger99]

By the way, the info above is technically correct, and Imperial bolts of the commonest grade on the Mini "should" be marked "S" rather than "8.8". So the UNF bolts sold as 8.8 ARE NOT COMPLIANT WITH ANY OFFICIAL STANDARD!

I am sure that my 1984 City E had some of these from new. Make of that what you will....


Nothing stops a manufacturer from making bolts with non-standard dimensions and any strength that they like. They probably were 8.8 in everything but dimensions, but the practice makes it very difficult to identify bogus parts that are dangerous when some of the good parts have bogus markings!

[Ethel]

Indeed, it'd be much easier to make a hash of almost any other job on car brakes.

Regarding bolt markings, they are different systems for showing material strength. It'd be interesting to know if there's any relation to the thread pattern, or just the standards authority of the manufacturer.

[the.stroker]

Thread tidied up, some good information here to answer the OPs question ref bolts!