Fine thread bolts vs coarse

[Atomic]

Ok, I'm trying to understand something. If a grade 5 comes out of the hole, why are most of the people here replacing it with a grade 8? Do you know something that the engineers don't when they designed it, or is it the bigger is better speech?

 

[swbradley1]

I have the new bolts so I put grade 8 in everything. Ask Gimp, I just replaced a bolt on my 6-foot finish mower last Sat with a grade 8 when the grade 8 I took out looked okay, other than a little dirty.

I have a bunch of new grade 5 but they are only if it's an emergency and I can't find an 8.

YMMV

 

[F18hornetM]

Most bolts are not critical fasteners. A grade 2 will hold a fender or mud flap on. Although I only use grade 5 or better. Except for steering gear box mounting bolts or something critical like that, or for authentic purposes, no need to worry over replacing a grade 5 with an 8.
Like someone else said, I try to re-use bolts. But if they need replacing, Im not going to use fine thread bolts on tailgate hinges etc .

 

[F18hornetM]

I have the new bolts so I put grade 8 in everything. Ask Gimp, I just replaced a bolt on my 6-foot finish mower last Sat with a grade 8 when the grade 8 I took out looked okay, other than a little dirty.

I have a bunch of new grade 5 but they are only if it's an emergency and I can't find an 8.

YMMV

We only stock grade 8 bolts in our bins at work, just easier to keep one grade. Also seems like for whatever reason grade 8 doesnt rust as fast. Nice working with new bolts for sure.

 

[Karl kostman]

I know there is a reason that these trucks came with all fine thread bolts, BUT if I have an option I virtually never put fine thread bolts back in, I will always put a coarse thread grade 8 bolt with a nyloc nut back on! This is especially true if its in a location that I have to stand on my head to get the old bolt out!
KK

 

[John S-B]

I've read the argument that the bolts is a good reason to buy a parts truck, but I sure wouldn't want to have bought my truck for the bolts! I've had to cut off too many to count because the rusty threads stripped. The threads on the bumper bolts I've removed were all mangled too.

I have my wife convinced that whenever I say "I'm going to Tractor Supply to buy some bolts" that I'm actually leaving to go visit a girlfriend!

If you could buy a girfriend at TSC, she' probably be like the rest of the stuff they have, Chinese.

 

[MyothersanM1]

If it is a critical safety type item or major load bearing and it's fine thread, that is what I put back in. Also, obviously, if a hole is tapped with fine that is what goes in. When I buy military issue installation kits, I always use the included hardware which are, more often than not, fine thread. I have no problem using coarse thread and have it used to replace certain fine thread applications while working on the truck. I used stainless steel coarse thread bolts when I replace the muffler. The important thing is I always buy quality. Usually Grade 5 or better depending on the load. There is a hardware store local to me that specializes in quality bolts. I buy from them and when I can't find it there I go through McMaster-Carr. I use Home Depot stuff for light load applications like side reflectors or cab tunnels.