Neil
Supporter
When I answered OP's question, I had not intended to write a book about fasteners- Carroll Smith has already done that. The general idea is use the best quality fasteners that you can, especially in critical areas. Stainless (303/304) bolts might be entirely acceptable if they are big enough but that isn't generally the case so alloy steel bolts are generally used due to cost & availability-- and they are just fine. I don't encourage anyone to rush out and copy what I've done- your applications are probably different than mine.
In his book Carroll Smith also recommends against using commercial bolts in his cars, I noted my experience with ARP only as an example of how even a respected company can get things wrong now and then. My problem with commercial bolts is that you really don't know what you're getting. Other than size and ultimate tensile strength rating ("Grade 8", etc), head style (hex head, etc), and plating, everything else is unspecified.
An aircraft, military, or aerospace bolt is covered by a VERY comprehensive set of specifications- all of the previous specs plus the material (alloy steel, CRES, etc), shear strength & UTS over temperature, class of threads (3A, etc), notch sensitivity, fatigue specs, and on & on. Uncle Sam pays a lot for those bolts but they are the best you can get. AN/MS/NAS bolts are inspected over & over again. You're right, surplus bolts do not have certification paperwork but I don't care. Meeting their AN/MS/NAS specs is good enough for me.
You are right about a failure at 130 mph being certainly more catastrophic than one at 50 mph, but I'm looking at not having that failure at 200 mph.
About my rivets- the layout patterns are per the FAA handbook. 75ksi A286 or Monel rivets are needed to achieve the full strength of my 7075-T6 stressed panels (yes, they are stressed, forming part of the chassis structure itself). Pop rivets are fine for fastening non-stressed panels and they cost a heck of a lot less.
Your point about leading a novice down the garden part is well taken. Building a car is a learning experience and learning as much as you can about the "how & why" a car is designed & built the way it is is the key to gaining vital knowledge & experience. Sharing that knowledge & experience on forums like this is a good thing. Since there are so may forum members with so different levels of expertise it is difficult to answer a question posed by someone you don't know.
In his book Carroll Smith also recommends against using commercial bolts in his cars, I noted my experience with ARP only as an example of how even a respected company can get things wrong now and then. My problem with commercial bolts is that you really don't know what you're getting. Other than size and ultimate tensile strength rating ("Grade 8", etc), head style (hex head, etc), and plating, everything else is unspecified.
An aircraft, military, or aerospace bolt is covered by a VERY comprehensive set of specifications- all of the previous specs plus the material (alloy steel, CRES, etc), shear strength & UTS over temperature, class of threads (3A, etc), notch sensitivity, fatigue specs, and on & on. Uncle Sam pays a lot for those bolts but they are the best you can get. AN/MS/NAS bolts are inspected over & over again. You're right, surplus bolts do not have certification paperwork but I don't care. Meeting their AN/MS/NAS specs is good enough for me.
You are right about a failure at 130 mph being certainly more catastrophic than one at 50 mph, but I'm looking at not having that failure at 200 mph.
About my rivets- the layout patterns are per the FAA handbook. 75ksi A286 or Monel rivets are needed to achieve the full strength of my 7075-T6 stressed panels (yes, they are stressed, forming part of the chassis structure itself). Pop rivets are fine for fastening non-stressed panels and they cost a heck of a lot less.
Your point about leading a novice down the garden part is well taken. Building a car is a learning experience and learning as much as you can about the "how & why" a car is designed & built the way it is is the key to gaining vital knowledge & experience. Sharing that knowledge & experience on forums like this is a good thing. Since there are so may forum members with so different levels of expertise it is difficult to answer a question posed by someone you don't know.