Author Topic: Jack stand ratings  (Read 1529 times)

Offline Glen

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Jack stand ratings
« on: August 31, 2012, 03:06:35 AM »
OK my turn to ask a stupid question. How are jack stands rated?  Say they are rated at 3 tons, is that 3 tons each or a pair? 

My neighbor down the street put 4 jack stands and a floor jack out for the trash, I could not pass that up.  I suspect the jack stands were thrown out because of some surface rust on the base.  I donít think they are weakened at all but I am thinking of load testing them.  I have always been on the safe side assuming the rating is as a pair but if I am going to load test themÖ. 
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Offline The Tassie Devil(le)

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Re: Jack stand ratings
« Reply #1 on: August 31, 2012, 05:03:45 AM »
G'day Glen,

You are blessed with good neighbours where you live.

I believe that Jack Stands are rated as pairs.

But, trying to rate your own, you would have to destroy one of the pair as you would have to load them to breaking point.   Then, halve the weight that caused the first pair to collapse, and you would then have the load limit of the remaining pair.

If the rust is not structural, then you should be relatively safe to use them under your car, as 4 would safely hold up a 3 ton vehicle.

A good engineer could cast their eyes over them and I am pretty sure they would pass with flying colours.

Bruce. >:D
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Offline Jeff Wilk

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Re: Jack stand ratings
« Reply #2 on: August 31, 2012, 06:10:06 AM »
Wow thats a great question!!!  Ive always assumed they were rated individually but sold in pairs.  Have no idea now that you mention it though......
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Offline Gene Beaird

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Re: Jack stand ratings
« Reply #3 on: August 31, 2012, 08:57:35 AM »
Now I'll have to go to a parts house and read the fine print on the box.  I had the same assumption that Jeff had on them. 

Glen, you scored!!

Gene Beaird,
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Offline waterzap

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Re: Jack stand ratings
« Reply #4 on: August 31, 2012, 09:14:47 AM »
3 tons per pair.
From a Sears ad.......

This pair of Jack Stands from Craftsman features a rated capacity of 8,000 lbs. per pair.

 Also usually there are warnings not to use 4 stands at the same time. Probably safer to have one set of wheels on the ground.
« Last Edit: August 31, 2012, 09:17:57 AM by waterzap »
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Re: Jack stand ratings
« Reply #5 on: August 31, 2012, 09:23:06 AM »
You shouldn't use 4 stands under the frame, since the car will want to rest on only three and it won't really be completely stable.  If you have to put the car up at both ends, put the front stands under the frame and the rear stands under the outer parts of the rear axle tube -- that takes advantage of the self-leveling property of the rear springs.
Art Gardner

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Offline Glen

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Re: Jack stand ratings
« Reply #6 on: September 01, 2012, 12:59:18 AM »
My plan was to do non-destructive test.  In the shipyard we tested things like this based upon the rated capacity also known as SWL or safe working load.  Somewhere there would be a document that lists the test load which is around 1 Ĺ times the SWL.  If it takes the test load with no problem it is assumed to be safe at the SWL.  I say assumed because that is dependent on if there has been damage to the item or not since the test. 

My plan was to use the 25 ton shop press which has a gauge that reads out in tons and load the jack stands to at least the SWL.  But I need to know what the SWL is for one jack stand. 

I have seen the jack stands advertised as a say 3 tons per pair or 3 tons each.  But they donít seem to be doing that any more.  In the interest of safety the rating on the jack stand should say per pair or each.  They donít. 

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