shane0328

so i just bought some craftsman jackstands and they came out of the box with a fat chip right out of one of the pads so im not about to crawl under my car with them. and i took it to work and tested the metal and its just plain old carbon steel and that just doesnt seem right to me so if you know of any jack stands that are made out of anything stronger than carbon steel please let me know. also what do u guys put under the car for extra support (blocks of wood, etc?)

garygnu

thats as good as it gets.return them for another set.you can put tires on rims under the lifted wheels.

jc98ss

iTrader: (13)

whenever i have to get under my car, i always use a cinder block under every tire as well as jack stands under the frame on all four corners......i got 4 cinder blocks plus i cut a 2x8" board into 4 pieces, each about 12 inches long and they sit on top of the cinder blocks.....it's solid as a rock and i have no worries about crawling under it.....one of these days i'll just buy a lift.

Silverback

ARG... NEVER use cinder blocks, they do not have a high compressive strength, they will eventually crumble on you.

Mild steel is a good material to make jack stands out of. it has good compressive strength, and isn't likely to get hard/brittle areas around welds... You're better off with them bending with mild steel then breaking if made out of higher grade steels...

Mike52

iTrader: (1)

That’s one of the dumbest things I’ve ever heard, it’s a disaster waiting to happen, sure hope your life insurance policy is paid up. Just because you got very lucky a few times doesn't mean they won't come crumbling down one day.

jc98ss

iTrader: (13)

the cinber blocks i have are new and the board on top of it distributes the weight from the tires evenly, but they are the last thing to go under the car, the jack stands go under first and sit against the frame.......all of the weight is on "jack stands", the blocks are just a backup, it works for me.

01ssreda4

iTrader: (96)

I love back ups....I shove rims or ramps under the subframe connectors. I figure if something falls and my rim gets scratch well it probably saved my life so the hell with the rim.

As far as the jackstand, you have about 900 pounds at each corner of the car. I use 6 ton jack stands at each corner. I'm not remotely worried about breaking one. Why you would think carbon steel is inferior is beyond me....

Silverback

I do exactly the same thing, put it up on jackstands and throw the tires under it if i pull the tires off... I have once managed to shift a car's weight enough that I almost knocked it off a jack stand and the tire would have saved me if I did.

as far as the cinder blocks go, that still stupid, so you're saying that if the weight shifts it will land on the block- smack one with a hammer and see what happens to it, then multiply that by the say 1000x or so (say comparing the weight of a hammer to the corner weight of the car)...

jc98ss

iTrader: (13)

i use two 4 ton stands in the front, the back pair are 3 ton.....it's not going anywhere unless someone decides to go all running back into the side of my car while i'm under it....sometimes i put a couple of hydralic jacks under there too, as well as the jack stands and blocks......believe me, i wouldn't crawl under a car if i wasn't sure about it being safe, having one fall on you would be a f*cking nightmare........the blocks have just been there as an extra layer, but i'll grab a set of metal ramps since i'm about to swap out mufflers on my true duals

usafws6

iTrader: (10)

he wants cromoley jackstands that would probably be 75 bucks a piece. lol. mild steel has worked for decades.....have faith in it.

lil-bit

what about cinder blocks filled on each side with concrete ? no still not strong enough?

zipster

iTrader: (5)

I use blocks of wood, they are built out of 2x6's 14 inches long, paired side by side then the next layer is 90deg from the first, all nailed together at each layer. Now, for anybody questioning these, I repair forklifts for a living. Some weigh 30,000 lbs. We jack up the truck and put one block under each wheel. you cannot compress the wood because its a solid piece and it cannot slip out from under the unit. Metal on metal can slip out.

They look like this

Silverback

Assuming average weight of concrete, that would be a 65lb block of it... do you really want to buy, make and then move 65# blocks of concrete that would only be strong in one direction? Go for it. OTOH, if you're dumb enough to think this is a good idea just use the normal cinder blocks _before_ you reproduce and save us all a little time and money...

wood cribbing is a great approach as long as you make sure you have it put together in a way that it can't slide. I have some nailed together pieces that are somewhere around 5" tall that lock together so I can stack them under the tires at any height I want...

MT0911

Whenever I get under my car, this is what I do:

1. I have jackstands on all 4 jacking puck locations
2. I leave the floor jack on the rear crossmember with a block of wood to widen support
3. I also have a set of race ramps that I put under the car with me on both sides
4. I also place the wheels/tires under with me as well if I take those off.

I am a safety freak ... Those horror stories have scared me lol

BADD SS

iTrader: (4)

I hate to say it, but this could not be more inaccurate. Concrete blocks have extreme compressive strength. Where they are weak is in tension, or if they get impacted. If you drop a block (which may happen before you get it) it can get cracks that you dont see and then when another impact happens or even over time with water laying on/in them in freezing climates they get severely weakend. But a single 8x16 triple cell concrete block has about 38,000 lbs of compressive strength. Why do you think they are used as walls? Honestly, if they were that weak, the bottom row of block would crumble as you say, when there is 5,000 lbs above it.....

That being said, because you dont know how they have been abused, its not worth the risk. Harbor freight 12 ton stands are cheap, and strong as can be. Or spend $250 on almost the same ones from snap on.

Silverback

They only have compressive strength of a cinder block is only high in one direction (cells facing up) and even that can be as low as barely over 1000psi for an undamaged block, a fraction that of concrete. When used in a load bearing application the cells are filled with rebar and concrete, which are many times stronger than the cinder block itself.

Unreenforced they are used to build walls for the same reason that 2x lumber and OSB is... it's faster and cheaper than using other materials and it's strong enough...

Without some way to guarantee that it won't see any side loads it is not a safe material to use to support any significant load.