Grade 5 bolts v Grade 8 bolts

[daddycreswell]

The OEM bolts have a nice shoulder that allows the belt to pivot around. I doubt you can find something similar at a local parts store or even HW store. 7/16 fine thread, yes. 7/16-20 with a shoulder, very doubtful.

This may or may not matter depending on what type of belts you're putting in.

I used the OEM bolts but I didn't like how loose the cables were, wanted to tighten them down some.

 

[JWMcCrary]

I buy all my bolts at tractor supply. Well at least when they have a size I can use. They sell all their bolts by the pound and by color. Doesn't matter how many or what size you get. silver is G2, green is G5, gold is G8. Just throw them in a bag and go pay by the pound.

Grade 5 is actually good for almost everything you would do on a Bronco. There are some that will tell you a Grade 5 is actually better suited to an impact load than a G8. I'm not going to argue that either way. I tend to buy almost everything G5 these days but sometimes I buy G8 a lot of grade 8 1/4-20s because I use a lot of them fabbing things up that could probably be better done with G2 5/16, but I like the smaller bolt heads.

Amen, love tractor supply for bolts and nuts and the way they price them.

 

[Fireball05]

Daddy - if you've already got the OEM bolts, why not just some plastic washers above and below the belt to help take up some space?

 

[WARDOG]

Grade 5 can flex more before it breaks.

And his name was 'BINGO' !

You are going to have a lot of other components in that chain fail before you are going to break a grade 5, 7/16 NF, rolled-thread bolt.
Likely the floor pan itself will rip out first.

I'm not an engineer, BUT... I am a machinist, and go though a lot of bolts.

 

[KyleQ]

Finding 7/16 fine thread grade 5 or 8 is proving to be impossible locally.

Got an Ace Hardware? They always have that stuff- or the two around my just ROCK for hardware..

 

[Glass Pony]

My local True Value Hardware has a way better selection than Lowes and Home Depot.

 

[bmc69]

The world has gone grade 8 and stainless crazy. There's a lot of salesmanship here. I'll only listen to a real engineer with the sheepskin to prove it. Grade 5 can flex more before it breaks.

But....

The grade 5 bolt will have yielded to its elastic limit and then failed completely from an applied load that wouldn't even have started to yield the same sized Grade 8 bolt.

But again..either grade are way stronger than the belt, or the human body it is retaining....and likely even the structure the bolt is pulling on.

Signed: An injunear. BSME, Purdue University, 1985.


Hardware grade stainless hardware is, by and large, a poor substitute/choice for any place where the load might be significant and safety-critical since it is typically weaker than Grade 5 steel hardware, although can be purchased with certs that are roughly equivalent to Gr5.

 

[bobscott]

But....

The grade 5 bolt will have yielded to its elastic limit and then failed completely from an applied load that wouldn't even have started to yield the same sized Grade 8 bolt.

But again..either grade are way stronger than the belt, or the human body it is retaining....and likely even the structure the bolt is pulling on.

Signed: An injunear. BSME, Purdue University, 1985.


Hardware grade stainless hardware is, by and large, a poor substitute/choice for any place where the load might be significant and safety-critical since it is typically weaker than Grade 5 steel hardware, although can be purchased with certs that are roughly equivalent to Gr5.

Signed and sealed: The OP is from TN after all so I figure we need a TN PE, you never know when the Board is watching.

 

[70_Steve]

I'll only listen to a real engineer with the sheepskin to prove it.

Signed: An injunear. BSME, Purdue University, 1985.

In case there was a question, I happened to find a picture of bmc69 right after receiving his sheepskin, along with a couple others of the graduating class of 1985.

 

[bmc69]

In case there was a question, I happened to find a picture of bmc69 right after receiving his sheepskin, along with a couple others of the graduating class of 1985.

*sniff* I was such a handsome lad back then...so happy go lucky...