I think Truckdog nailed that one. Rivets allow more flexing without putting as much stress on the surface of the metal. I believe grade 8 bolts are stronger but dont have the advantage of minimizing the stress on the metal. On the other hand, I would rather crawl under the truck and remove a 7/16" nut and bolt to change out a running board bracket than try to grind off the stock rivets.

 

You might look at the Big Flats web site because it gives a short instruction page on during this. I did mess up the look of one of the rivets that I set, then came back and replaced it. It was just as hard to remove as the factory ones. So the spreading of the shaft seems to be the aspect that mostly holds things together. As for the stresses imposed by one method or the other, as I recall I read a number of technical threads on web sites like Practical Machinist and others that contained a lot of technical stuff describing the merits of rivets. I just jumped ahead to the bottom line.

Also, as I was thinking on this at dinner tonight, I recalled that Marmon-Herrington used grade 8 bolts themselves in their conversions. Because they had to spread the frame rails to get the transfer case cross members into the inner rails they cut out the rivets holding the third cross member on the F-2/3 models and replaced them with bolts. I've pulled three of these trucks apart and they've all had the same modification. Stu

 

Not sure that's true, in fact I really doubt it. There are a couple of movies on-line of the Ford and Chevy assembly lines back in the '30's. They show cold riveting. It may vary between cars, trucks, and big trucks, but I don't see any hot rivets. It would be impractical to keep the rivets a uniform temperature.

The first couple minutes of this one show a good assortment of what I mean:

 

Awesome..............

 

Must be something to it as the tall buildings in New York, during that period, were put together with hot rivits. chuck

 

Hot rivets work great when the job location is moving. Cold rivets are cheaper and easier to install if you are doing a lot of riveting in a dedicated job location, like a station on an assembly line.

 

Wish I could get my hands on one of those old hanging riveters you see in that video!


I wonder if a gagebilt would work on these old frames.

 

Rivet squeeze tools aren't crazy expensive if you're doing a lot of them. Here are some:
http://www.aircraftspruce.com/menus/...squeezers.html

 

I'm impressed and agree with your reasons why. But, if I were to do the same thing, I'd always be worried if I set every rivet well enough that it would never pop out. Thus, I'd have to throw in with the grade 8 crowd and bolt it together.

 

Just curious if that's the way they were/are put together in an earthquake zone like San Francisco?

 

Turn that around; Do you want to be re-torquing crossmember bolts every 6 months to be sure they still have tension? I'm not sure Grade 8 bolts are the appropriate fastener to replace rivets; structural bolts are a different metallurgy and are torqued to a stretch. The nuts in particular are heavier. You don't want to ever have to go back to re-tighten the girder bolts on a skyscraper.

 

I probably just remember incorrectly. George didn't usually make a statement he hadn't researched very thoroughly.

 

I remember as a kid watching them build tall buildings in Pittsburgh and they would heat the rivets until red hot in a small kiln and then throw them to a man that would catch it with a funnel. He would then put the rivet in the hole and one man would hold the head and a man on the other side would peen it over with a large pneumatic hammer. I'm sure that is how most of the older buildings were made in this country. Now they use bolts with nuts.

Totally Stainless has these machine screws available at the bottom of page 114 of their catalogue:
UNSLOTTED TRUSS HEAD - COMMONLY USED TO REPLACE RIVETS

This has been a discussion here and on almost every other old vehicle forum. You can spend a lot of time reading but basically most come to the same conclusion that fatfenders noted previously: Grade 8 bolts that fill the holes are just fine for our applications.

I had to remove the rivets from the front spring pivot mount on the rear of my F-2 in order to get the pivot pins out. I found that the replacement grade 8 bolts did not quite fill the holes so I drilled them out exactly one size larger and used larger grade 8 bolts would fit perfectly with no slop. I didn't use stainless noted above just plated grade 8 hex head.

 

Gotta respect a man who ain't afraid to share PICs of his Barbie jackstands with the world!

 

Or the spare tire replacement