> Also from a metric country, things like number and wire gauges are odd to me as well as I only occasionally have to deal with them.
Well wire gauge is typically not how one would identify a bolt. Number wire gauge would typically be referred to by the units (either AWG or mm^2).
> If you are looking for fasteners for specific industrial use then I'd assume you would have the expertise to select the appropriate fastener or some internal engineering specification to follow.
Typically, yes although a friend was lamenting in the difficulty in finding a castle nut for an automotive application on the McMaster site.
> You don't just buy something from the scientific bolt category on Amazon. You may also require material certificates etc, which I don't believe is something these online options typically offer, though I may be wrong.
Well, McMaster offers will call (at one location) and offers phone support. The other folks Amazon is trying to compete with (Fastenal, Grainger, MSC) have a variety of B&M locations. I can't speak to material certification but I've purchased a certified caliper from Grainger no problem. Meanwhile Amazon still has the counterfeit issue to grapple with.
Yeah wire gauge fasteners is definitely weird, not something I've used, but from a quick look they exist, although I'm not sure if they get much use.
Castle nuts are a bit of an oddity too. Id assume your friend is possibly using them for trailer bearing retainers or possibly some really old suspension items. Not even sure there is really even a specification the ones available here seem to adhere to.
They are something I've generally gone out of my way to engineer out of a lot of applications as there is better options available.
Well wire gauge is typically not how one would identify a bolt. Number wire gauge would typically be referred to by the units (either AWG or mm^2).
> If you are looking for fasteners for specific industrial use then I'd assume you would have the expertise to select the appropriate fastener or some internal engineering specification to follow.
Typically, yes although a friend was lamenting in the difficulty in finding a castle nut for an automotive application on the McMaster site.
> You don't just buy something from the scientific bolt category on Amazon. You may also require material certificates etc, which I don't believe is something these online options typically offer, though I may be wrong.
Well, McMaster offers will call (at one location) and offers phone support. The other folks Amazon is trying to compete with (Fastenal, Grainger, MSC) have a variety of B&M locations. I can't speak to material certification but I've purchased a certified caliper from Grainger no problem. Meanwhile Amazon still has the counterfeit issue to grapple with.