Hey guys, I bought an engine hoist & leveler from the Englishtown swap meet this weekend- got both for $129. The hoist was made overseas; the instructions are horrible! I just threw 'em down and built it like the picture.

Anyway, if you've got a REAL engine hoist (like OTC Stinger or Sunex or etc), what grade are the bolts?? All the bolts in this kit are metric, and are stamped "4.8" !! I think I'll be changing those out for at least 8.8's (SAE grade 5), preferably 10.9 (SAE grade 8) if I can find 'em. But 4.8- especially for the chain itself- seems too damn weak. What the heck's a 4.8 in SAE, a grade 1??

But if everyone's "real brand name" hoist uses weak bolts, I guess I will too.

I just don't want to get killed - or worse (haha) have the engine fall on the ground because a bolt snaps.

 

Actually - even if you don't have a $400 hoist, but have a cheap one like me, what's stamped on the ends of the bolts? Are they 4.8 strength too?

 

i dont remember what brand mine is, got it at checker for like 200 bucks or something...

anyways grade 8 everywhere I see

 

i have an AC-Delco brand hoist that your typical chevy dealership would use. All grade 8 or higher throughout the entire thing.

 

i've got two american made hoist in my lab one has gr 5 bolts and other has a mis of 8.8 metric bolts and what looks like hardwear grade pins. not sure what mine is at home, i'd guess hardwear grade bolts. don't think any of the hoist i have use tapped hole, you could replace all the bolts with american nuts and bolts.

 

mine has grade 8 in every thing ....

 

mine uses grade 5 bolts (BIG ones) and what looks and feels like cheap hardware store pins.

i donno the brand, but its blue.

 

i have one from harbor freight and it used grade 5 bolts. i believe my dad swapped them for 8s though.

Mr. Dude i think we have the same one because mine is blue, had grade 5 bolts

 

Most I have seen have grade 5's/

 

I'm tired, but...

Metric 4.8 bolts have a tensile strength of 40 kgf/mm^2. Tensile yield strength is 32.

SAE grade 1 has a tensile strength of 60,000 psi. Tensile yield strength is 36,000 psi.

SAE grade 5 has a tensile strength of 120,000 psi. Tensile yield strength is 92,000 psi.

SAE grade 8 has a tensile strength of 150,000 psi. Tensile yield strength is 130,000 psi.

If I did my math right, 40 and 32 ks/mm^2 convert to approximately 56,893 and 45,514 psi, respectively.

So it looks like ultimate strength matches up with a grade 1, but yield strength fits in between a 1 and a 5. If it were me, I'd want to pick up some 10.9s.

Interesting info that I just learned for metric bolts:
the number before the decimal is 1/10 of the minimum tensile strength. The number after the decimal is 1/10 the ratio of yield strength to ultimate strength. Of course, by now, nobody cares.

MikeS

 

Wow, thanks guys! I didn't expect that many responses! And yeah Checker definately counts as name brand... there's nothing at all anywhere on my hoist that has a company name. So if a bolt failed and I got injured, I'd have nobody to sue!! Clever! And I think Checker/Autozone/Pep Boys usually sell Big Red or Torin shop equipment... that's brand name enough for me!

So, after seeing everyone's answer, I'm definately going to go hunt down some grade 8's (or 10.9's)! Thanks everyone!!

Ede, I have a few threaded holes; it's a "folding" hoist, so where the legs fold up, they threaded the holes for the caster bolts so there's no nut to interfere with the way the legs nestle into the base. But ya know, I never checked the pins (two for each folding leg, one for hoist adjustment) for a strength mark- I'll have to look at those, too. I might replace them with bolts, too!

Mike, thanks for digging up that info! I always wondered what those numbers meant! Glad to know they didn't give me less than a grade 1! Stupid foreign tools... at least all the welds look strong- after seeing the bolts they gave me, I checked over every weld I could find.

And no wonder it took forever to drag that out of the swap meet.. the box with the base in it weighed 55 pounds (25 kg). The rest of the parts were in another box that was 132 pounds (60 kg)!