The Stovebolt Site Forums The Shop Area Driveline Replacing Rivets for bolts

Hi,

I know this debate has been going on forever, but im looking for some bolts to reattach my crossmember back to my frame on my 57 3100. Im having my frame powder coated and im going to reattach it after. Im looking for a bolt that will not rust (since it will be powerder coated already I didn't want to paint the bolts individually) and have the strength to hold everything in place. Let me know what you think.

Thx

On my 50 I used 5/16 NF grade 8 bolts to replace a few rivets. Flat washers and lock washers.

Make sure what ever bolts you choose have a shoulder. Self locking nuts are an option

Add checking these bolts for tightness to your chassis maintenance schedule

Thank you, Did you paint it or left them alone with the zinc coating

I did, but rust is not an issue where I live.

I wound up bolting in one of the front spring hangers because the rivets were loose (the other side had been bolted in many years ago) using grade 8 bolts tightened till my eyes bugged out. My plan is to paint the bolts and nuts along with the rest of the frame when I can get it sandblasted. I had a few other rivets that were loose and tightened them up by heating and peening (got a tool that goes in my air hammer). Worked pretty well. I also plan on riveting on the running board brackets that I had to replace.

Wow that's cool, thinking back I should of tried to re-rivet them back on with that tool you had.

Here's a pic of the bucking bar I made out of a chunk of my F250 tie rod and the air hammer bit that I got from Amazon.
Heat the rivets cherry red and peen them over.

Don't use stainless steel, they won't rust, but they are not very strong either. Drill the holes to fit the smooth part of the shank of the bolt ( not threaded part ).

Anytime I replace rivets with bolts, I use Allen head shoulder bolts and ream the holes for an almost press fit. Drill bits simply don't make accurate enough holes to prevent shifting between the parts you're trying to hold together, no matter how tight you get the bolts. If bolting was "good enough", why would GM have gone to the trouble and expense to rivet crossmembers in the first place?
Jerry

Jerry brings up a few great points.

One major advantage of rivets is that the peening operation will swell the body of the rivet to fill the holes. So that does greatly reduce the possibility of the parts shifting. The riveted joint is strong in shear but not in tension.

Riveting is a less expensive manufacturing process than a bolted joint. You only have one piece to insert and one tool to complete the operation. Think of a simple press type tool (hydraulic C-clamp) to assemble it. A rivet works better in thinner joints where you cannot get enough bolt stretch to maintain clamp force.

A properly designed and assembled bolted joint should not move. The friction between the parts that is created by the clamp force (bolt tension) prevents movement.

Rivets, when installed hot do have strength in tension (just try to pry a rivet joint loose to illustrate that.) They do swell to fill the hole, and once the head is formed on the back side, shrink lengthwise as they cool to put the rivet in tension and compress the joint.

When I worked as a sheet metal fabricator, making tail sections for C-130's and rear boom sections for Bell helicopters, among other aircraft subassemblies for a factory in Nashville, we spent a lot of time in training to install rivets properly. The rivet must be an almost perfect fit in the hole, and when it's expanded ("bucked") it not only clamps the pieces together, it also expands to fill the hole, creating a bond almost as strong as a solid piece of metal. The very best riveted joints are done with "hot" rivets, ones that are installed while cherry red and hammered into place with pneumatic rivet guns. Look at the construction of older buildings or bridges with riveted steel beams instead of welded ones for a good example of hot riveting. High rise buildings used to be assembled with rivets heated on a charcoal forge and thrown to the riveting crew who caught them in funnel-shaped metal cups and installed them with tongs and pneumatic hammers while they were still red hot.
Jerry

I recall seeing an old video of a riveting crew on a high rise building. Besides being way the heck up there (most without fall protection that's required today), they were handling red hot rivets. Pretty inspiring. Makes my hot riveting on a frame in my driveway seem pretty tame.

Thanks all. I should of tried to rivet the crossmember and upper shock mount bracket before sending it off to the powder coater. Always doing things in the wrong order. I will ream the hole and find a tight fitting bolt (using a bolt with a shoulder).

Thanks,

You’ll have no issues. There are replacements bolts on my 50 that have probably been there since the 70’s

Bolts on the upper shock mounts is a pretty common repair for the hobbiest. Plus some of the locations have blind holes. So it would be difficult (not impossible) to re rivet.

Good tips up above

The crossmember on my truck is designed to unbolt. Not sure if thats true for your year.

Good luck

I'd have to agree. The bolts holding on the rear hanger for the left front spring has likely been on there since the 50's or 60's. It was nice and tight with no evidence of movement. I found a couple of running board brackets that were bolted on as well.

I had to move the front upper shock mounts to add power steering to my 59". I used grade 8 hardware and torqued everything to spec for the size bolts I used. I don't really see an issue, I know that the original rivets are the preferred method but if you use quality bolts there shouldn't be a problem.

Particularly on shock mounts, it's the fit of the bolt in the hole that's critical, not the torque or the strength of the bolt. Even a few thousandths of slop in the holes allows the parts to move in relation to each other, no matter how well the bolt and nut is tightened. Eventually the holes get egg-shaped and no amount of retightening can keep the holes from getting bigger. If a formerly riveted part is removed and bolted back on, at least use shouldered Allen bolts in holes reamed for an exact fit with no opportunity to flex. Drill bits simply aren't capable of making accurate-diameter holes.
Jerry

Hi,

Thank you for all the tips! Is this a shouldered Allen bolt?

Yes, they're available in all sorts of shoulder lengths and thread sizes on Ebay. For chucking reamers to get the holes round and the right size, try Victor Machinery Co. (www.victornet.com). On a lot of the standard shoulder bolt sizes, they have reamers .001" undersize, which will result in a very tight interference fit, almost a press fit. Once a shoulder bolt is installed that way, it's almost a solid as a hot riveted joint. It also helps to grind a slight taper on the end of the shoulder to help force its way into the tight hole.
Jerry

Hi Jerry,

Thanks, in your opinion how big of a shoulder is needed. What length and does a nut screw on to the back side. Sorry for the silly questions, Ive never used one of these bolts before. How are they different than a bolt with a shoulder on it.

Thanks

Mark

I agree with Jerry that if you can't rivet an attachment, a tight fitting shoulder bolt would be next best. However, I disagree that a standard bolt tightened to the proper torque would loosen up and make the holes eggshaped. The clamping force of the three or four bolts for a shock mount will keep it in place for the life of the truck.
The shoulder on a shoulder bolt will need to be just shorter than the combined thickness of the frame and the attachment so that the nut, when screwed on will clamp the two together tightly. I think the complication of getting the right shoulder length and reaming the hole for a tight fit makes their use out of the range of the typical DIY guy. Of course Jerry has the skill and equipment to use them.

I usually let the shoulder bridge the distance completely, and use a thick flat washer under the nut to allow it to be tightened properly. Anybody who has any experience building dirt track race cars will agree with me about it being impossible for bolts to hold pieces rigidly in place under the compression/rebound action of a shock absorber. Amy slack whatsoever is going to result in motion between the parts on even a moderately rough road surface. Hitting a big bump at highway speed is going to make something in the suspension system move, bend, or break. The rule of thumb on the track was "Make it three times as strong as you think it needs to be, and don't be too surprised when it breaks!"
Jerry

With 5/8" and 3/4 bolt holes I usually use flange bolts. However, for a 3/8" hole I have been using crossmember bolts for over 40 years.

https://www.imperialsupplies.com/item/0009790

This has been the standard fix for semi trailer cross member to bottom rail repairs. Most trailer manufacturers use buck rivets or Huck bolts to attach the floor cross members to the bottom rail. Salted roads cause things to swell and rivets and Huck bolts break. I have a dozen dry vans in drop and hook service. I have used hundreds of these bolts and have never had one to break and they are simple to install. If the hole is a little too big or out of round it doesn't make any difference. Our floors stand up to a beating with forklifts with solid tires. A pickup frame will never take this kind of beating. I buy them by the box of 100. If you are going steel to steel you don't need the nylon washer. That is for steel to aluminum to prevent electrlysis.

I'm giving the squint-eye to the nylon washer. It would tend to make things loosen up. To truly isolate steel and aluminum, you'd need more than just a single nylon washer. You'd also need a sleeve to isolate the bolt.

I use a hard steel grade 8 washer with a big enough inside diameter for the shoulder section to pass through, and thick enough to let the nut tighten without bottoming out on the shoulder. The washer allows the proper clamping force to be applied, and the very snug fit in the hole positively prevents any relative motion between the pieces.

"One convinced against his will is of the same opinion still!" Kevin simply refuses to be swayed in his insistence on doing thing his way.
Jerry

Trailer companies have been using these bolts for almost 50 years. Fruehauf had them exclusive during the '70s. Now everyone has them. Imperial Inc., from whom I buy fasteners is a subsidiary of WW Grainger, has been around along as I have. It is a tried and proven product. In the 40 something years I have been using these bolts I have never had a bolt come loose because of failure of the nylon washer. Back in the '70s Strick trailers used a stainless steel washer to Isolate the bolt head from aluminum. After a few years of exposure tp salted roads, the stainless steel washer split leaving about .040 gap and it wasn't long after that the bolt broke. As far as isolating the bolt from the aluminum bottom rail, the bolt fits tight enough that salt spray does not get between the bolt and the aluminum. We have disassembled some of these bolts after years of service to do other repairs to trailers. And the bolts came out with no evidence of the white powdery electrolysis. In fact it was tempting to reuse the bolts. I can pull 3/8 Huck bolts and I can buck rivets 3/8 and larger. But I prefer these bolts over Hucks or rivets. I wonder of if you are criticizing a tried and proven product from experience for from theory.

I can't claim any experienced with these, but just saying that nylon washers don't have the compressive strength of steel or even aluminum (that's a fact, not theory), and I have seen plastic components "ooze" out from the connection.

Jerry, I'm not doubting that dirt track racing is extremely hard on suspension components, but I don't think the typical Stovebolt is going to get that kind of abuse.

I don't claim to be any kind of expert in plastics. My college degree is a BBA in accounting and pre law. But I have owned trucks since 1964 and have used these type of bolts since they hit the market in the '70s and I have many years of real world experience with these bolts and the washers that I call plastic. They do not compress nor do they "ooze'" out. I have tried so plastic suspension bushings that are supposed to last a lifetime. But they were a total disaster. The old fashioned rubber dry bolt bushings run a half a million miles or better on my equipment.

The term "Plastic" covers a wide variety of synthetic materials with different physical properties- - - - -Nylon, Teflon, Rayon, Dacron, etc.- - - -and those are just the petroleum-based products produced by DuPont. There's a story about how those names came to be. One of the very early "computers" back in the 1940's was tasked by DuPont with combining random syllables to suggest names for new products, resulting in the above names for the various products their chemists were churning out. One such name was rejected, after a researcher from another country pointed out that in his language, the word meant "outhouse"! That story was shared with me by a DuPont chemical engineer who also ran one of the race cars my father built engines for.
Jerry

The simple, effective, and more or less foolproof way to install shock absorber mounts, crossmembers, and other parts that carry suspension loads are "Huck" bolts. They're basically pop rivets on steroids and they clamp pieces together tightly and expand to fill holes completely, preventing any relative motion between parts. They're a lot simpler to install than hot rivets, and they have a 50+ year history of holding big rigs together. Some types of them can be installed without special tools- - - -nothing but an impact wrench is needed.
Jerry

Jerry, I think you are confusing Huck bolts with structural blind rivets. The largest Huck bolt or magna grip that can be pulled with air over hydraulic is a 3/8". The Huck 256 which pulls them costs around $3,000 without the pulling tip. The nose piece is around $500. I own two of them. I keep a 3/8 tip in one of them and a 5/8 tip because we do a lot of trailer repairs. The things that resemble pop rivets are usually called blind Huck or Monobolts. They are in places where it is impossible to use a buck rivet or Huck bolt. Truck manufactures use 5/8 and 3/4 inch Huck bolts. The machine to pull them costs them costs around $100,000. I'm not sure just what you would do with am impact wrench to pull either a Huck Bolt or a blind. Huck bolts are cheaper to install at the factory, but they break after a lot of salt exposure. I replace them with grade 8 flange bolts. I think this whole thread is going nowhere and probably should be deleted.

I don't think the thread should be deleted. It is getting a bit off track, but some good discussion and info here.
It's got me looking up some of the products mentioned.

@crenwelge I looked at the flange bolts. It looks like it has a round head, how do you keep it from spinning when tightening it. Thank you all for all the great information and options.

Thanks,

Mark

Flange bolts have a hex or 12 point head.

https://www.imperialsupplies.com/browse/fasteners/cap-screws-bolts/flange-bolts

The bolt part of a crossmember repair kit is actually called a ribbed carriage bolt.

https://www.imperialsupplies.com/item/0009790

When attaching to an aluminum bottom rail a nylon washer is used. For steel against steel it is not necessary. The nut is actually a flange serrated self locking nut. All three pieces are ordered separately at Imperial. We use these bolt a lot because having two crossmember to bottom rivet broken is an out of service criterion. In fact we had a unit put out of service just two weeks ago for having two broken Huck bolts.

https://safer.fmcsa.dot.gov/query.a..._query_string=CRENWELGE%20OIL%20CO%20INC

Had the driver been doing his job on a pre trip inspection, we could have saved a $500 fine and points that raise our insurance.

I was out at my shop this afternoon and noticed my bin of crossmember bolts was looking almost empty . Imperial is out of stock at the moment, but Zoro which is also owned by WW Grainger has them cheaper and ships them in 7 days.

https://www.zoro.com/zoro-select-carriage-bolt-38-16x1-14l-pk100-5zmt4/i/G6027192/#specifications

I used flange bolts when I shortened the frame on my 630. Does away with washers, too.

Ed