For those thread nerds.

[Tybalt]

....Fortunately, with Triumphs, there is an easy way to tell if there is something special about a fastener. All of the "common hardware" fasteners have a part number that starts with two letters. If the factory used a 6 digit part number, then there is something special about the fastener...

Another plus on the majority of Triumph callouts for UNF standard hardware is the length of set screws and bolts along fastener diameters can be determined just by looking at the part number. For bolts and set screws the two letters designate the basic type of hardware, the first letter designates the hex size of the fastener in sixteenths of an inch increments and the last two digits designate the length in eighth of an inch increments. A "P" suffix is added if it is a pointed end fastener. This means that an HU707 would then be a 1/4" UNF set screw with a length of 7/8" while an HB812 would be a 5/16" UNF bolt with a length of 1 1/2". Washers and nuts use the last digit for designating that hex size of the bolt or nut used so a 1/4" washer or nut carries a "7" as the last digit, a 3/8" nut carries a "9" as the last digit, etc. As for strength, it is on the order of an SAE Grade 5.

I have a problem with Grade 8 hardware as the quality of the stuff you can buy at the normal hardware store can vary substantially in quality and one of the downsides of increased strength is a typically decrease in fracture toughness. Yea, I know there are exceptions, but let's be realistic, none of us are going to go out and get something like Aermet 100 fasteners. The other issue that I have with hardware store SAE stuff is that you typically make 1/4" incremental jumps in length as opposed to the 1/8" increments mentioned above.

As for myself, I mostly use "AN" and "MS" type hardware on my Triumphs. Most of it uses 1/16" incremental jumps for the grip length and with all of the suspension shear load applications on these cars, I like being able to ensure that any fasteners installed in shear load applications carry that load on the grip section only and that no threads are placed in shear. This is a constant source of irritation with me when buying certain bits from otherwise good sources. They supply something as a kit and then cheap out on the fasteners. I can think of some suspension kit stuff I have purchased from a US based supplier and from a UK based supplier where the components themselves were nice, but the hardware was marginal at best. As a result, it's now standard operating procedure on opening up any sort of kit to go through and determine what fasteners I need because I won't be using the stuff supplied with the kit.

 

[DrEntropy]

This is a constant source of irritation with me when buying certain bits from otherwise good sources. They supply something as a kit and then cheap out on the fasteners. I can think of some suspension kit stuff I have purchased from a US based supplier and from a UK based supplier where the components themselves were nice, but the hardware was marginal at best. As a result, it's now standard operating procedure on opening up any sort of kit to go through and determine what fasteners I need because I won't be using the stuff supplied with the kit.

So true. Finding appropriate AN, shouldered bolts is like an Easter egg hunt sometimes. I no longer have access to Charpie or tensile testing equipment so have gone to the lengths needed when the application is suspension/load oriented. Aircraft suppliers for the "dougnut" bolts in the Lotus rear driveshafts. Learned that lesson early on with the +2... shear a bolt, lose hours of time and dollars fixing the resultant damage.

 

[Tybalt]

DrEntropy, I'm in a good place for getting the AN/MS/NAS stuff. There is a fastener supply about eight miles from the house that gets lots of good surplus stuff from military and air framer sources, Aircraft Spruce East isn't too far away for ordering and shipping or even picking stuff up on a will call basis, then there are other decent places like Pegasus Racing and Coast Fab for distant ordering. Plus there are aircraft service places at nearby general aviation fields that keep a supply of hardware for their needs and will sell to the public for a price (that is very favorable to them) if I get desperate for something and need it now.

I would think that you don't have as many options in Elsinore DK since Europe has been thoroughly metricated for rather long time and we haven't. While most stuff over here has been going metric over the last few decades, the DoD still pretty much lives in an inch-pound world so lots of quality UNF and UNC stuff is readily available if you are willing to find it.

 

[DrEntropy]

We've used Pegasus a lot.

And I'm actually in CONUS. :wink: