Ok so I will be bolting all of my crossmembers, suspension components, etc back to the frame of my truck (pics can be seen in my signature) and I need some advice on what bolts and fasteners to use. I have been told that Grade 5 bolts will be plenty and I will most likely go with stainless because I dont want these rusting through anytime soon. My question is which fasteners do I use? Do I use locking washers as well? The bolts will be 1/2" thick for pretty much everything and the shortest will be 2" long. I need something that isnt going to come undone from just everyday driving. Something that is going to be permanent unless I heat it up to change something out. I also thought about using Loctite Red along with this as well. Here is a link to the Loctite http://www.henkelna.com/cps/rde/xch...tredDotUID=productfinder&redDotUID=0000000ICK Any advice is appreciated.
Careful on the stainless as it can be a lower grade than you might think. The stuff around here is only grade 2 and I had to ask as it is not usually marked like the regular steel. If you want the rivet look you could go with carriage bolts or button head allen bolts and then fill the head with epoxy. I used split lockwashers when bolting the front crossmember on my 34 and will be taking them back out as I don't like the look and they spread apart when tightened. I am going to use stover nuts which are a steel locknut.
There is a lot of tech out there on the web about how split lock washers simply do not work. I do not, and will not use them anywhere. Only use graded hardware. It it is not marked with a grade, throw it away. Stainless is just fine as long as it is graded stainless. A properly plated bolt should not rust for a good long time. Grade 5 is plenty for almost every automotive application. Grade 8 is often overkill, but if it is just a few cents per bolt more, I buy it. Red Loctite might be a real pain if you need to take anything apart later. I would use the blue stuff.
Stainless steel fasteners have a tendency to gall if you don't use never seize on them. Fasteners are cheap for what they do and I would recommend using Grade 8. They resist corrosion and last a long time. You won't be wondering if it is strong enough.
MAIN THING IS THAT common stainless bolts that have TWO lines marked on the heads,...can often times be NOT AS STRONG or have the equivilant tensil strength as a common "grade 5" bolt ( common designation of three lines) ...and the stainless fastener ,..allthough PRETTY,..is going to fail..... not safe in my book. there ARE HOWEVER a number of specialty companies that make more durable / strong stainless fasteners. but as said, most of these are not available at some "corner store" that sells stainless fasteners as a "dress up " type of item.... most important is to build it SAFE....
Unless you are going to polish them why use stainless fasteners? Some grade 5 bolts with locknuts should work fine; this is the way most Kenworth truck frames were held together; at least they were twenty-five years ago. You should be painting everything so rust shouldn't be a problem.
Use grade 8 for all chassis and suspension components. Stainless isn't necessary, unless you're gonna polish 'em for a show-car. They'll be painted, so they'll last a good long time. Yes...use lock-washers. - Rick
I am for stover nuts and castle nuts with cotter pins or safety wire. I will use nylock only where you can't see it. If you need a lock washer, use a star washer or a wavy washer. I have now read far too many engineering studies that indicate that the aforementioned split-lock washers are just useless. They seem to have the same locking ability as a flat washer, or no washer at all. "I put a split-lock on it and it did not loosen up" does not mean the split-lock worked, it just means it didn't loosen up. Correlation is not causation. Sez who? Sez NASA: http://gltrs.grc.nasa.gov/reports/1990/RP-1228.pdf Document page 9, PDF page 11. And, http://www.boltscience.com/pages/helicalspringwashers.htm has some excellent data that indicates that using one WORSE than not using any washer at all.
http://www.amazon.com/Fasteners-Plumbing-Handbook-Motorbooks-Workshop/dp/0879384069/ref=cm_cmu_pg_t Read this book or any of Carol Smith's stuff. Very dry content but really informative.
and remember, if you use nylocs, they are only good for ONE application. if you take them off throw them away! Crimp nuts are good for multiple applications and look more like a standard nut
Chevy used 3/8" rivets to hold their truck frames together, I think 1/2" bolts might be a bit large for the job. More bolts, smaller diameter, might be better. And it would probably help to make the holes just the right size for the bolts...drill undersize, then ream to the right size, and use bolts with a long enough shank that they fit nice and snug in the holes. Stainless bolts are not really the thing for structural use....if you plan on never washing the salt water off the truck I could understand using them, but with even a little bit of care normal steel bolts will last forever.
If you use nyloc's remember the bolt has to pass all the way through the nyloc with at least three threads showing on the outside.
And above all, dont use a lock washer on top of a flat washer. I see this all the time, if the lock washer bites into the flat washer, what keeps the whole thing from turning?
I know a pro car builder who always puts a flat washer under a lock washer so it won't scratch the paint.
When I got my Heidts frontend, it came with all Grade 5 Hardware, Icalled them up and asked why for 2200$ they could't have used Grade 8 HW? Reply was that the G5 hardware was used so it would "deform" instead of shear. Maybe a metalurgist could chime in?
Keep in mind that those old frame's were made to flex unless you box them. Find a bolt that will fit the old rivet hole, not loose. Talked to a guy who sold only stainless and he said it was grade 5 at best. Those old rivets you cut out were swedged in, meaning they were put in and kinda squished, that's what made them tight and fit the hole perfect in the first place. I would have only removed the rivets that needed removed for your new parts.
If your fastener is turning under working load, it is not properly torqued. If it cannot be stopped from turning by being properly torqued, it is the wrong fastener for the job. The answer to that is probably. A grade 8 bolt is a harder alloy than grade 5. Depending on the size, 8's can have about 33% more permissible working load, and can have upwards of 50% more yield and tensile strengths. If you are running a properly sized, and properly installed bolt for the application and you are producing enough force to deform or shear a grade 5 bolt, you have a bigger issue to address than upgrading to grade 8. A typical grade 5 bolt has a proof load of 74,000 psi. Compare that to our favorite ER70S welding wire or rod, which has a yield strength of 70,000 psi, and the mild steel that it is passing through: 1018(53,700 psi), A36(36,300 psi), A513(72,000 psi). That said, if it makes you happy to use 'em, use 'em. If they do nothing more than make you happy, that is worth something.
The best of the best is MS or NAS hardware. If your lucky enough to have a surplus aviation outlet in your town go there. They are way, way ,stronger than even grade 8 hardware and they are corossion resistent to boot. The locking nuts are super and will never come loose. The down side is they only come in fine threads as fas as I know. I suppose you can order them online from somewhere but be prepaired cause they ain't cheap. Remeber, you get what you pay for. If you don't want to go this route, I suppose grade 8 is the next best thing. Stainless doesn't compare in shear strenght to grade 8 stuff. You can research that
I slip the bolts I'm going to use into whatever it is I'm going to bolt together, then add the thickness of a stainless AN washer and nylock nut. I cut the bolt a thread or two longer, and clean up the end on the grinder. It makes for a cleaner look, and the nylock is fully utilized. I will NEVER use a split ring lock washer. Not only do they dig up what's under them (including the paint/powder coat), but I've seen them break in half. I use the stainless AN washers because the outside diameter is shorter than a regular washer, and the inside diameter is snug to the bolt...and it keeps from digging up the coating under the nyloc when it's torqued down. Final strength use dictates whether I use a stainless, grade 5, or grade 8...
NO - the crimp will deform when the fasteners is assembled. the second assembly is not as secure as the first. We use tens of thousands of these every month. if one is disassembled, it is thrown away
If there is a Caterpillar dealer near you try them, all their stuff is grade 8 or better and is about the same price as at the hardware store. Also if washers are part of the deal they need to be as good as or better than the bolt and nut.
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