Impact driver ratings, max torque vs working torque - PeachParts Mercedes-Benz Forum

mpolli · #1 12-06-2010, 06:39 PM

I am in the market for a cordless impact driver, and I am learning (the hard way) that the max ratings on the tag aren't worth anything. It seems what you really need to know is the "working" torque, or the "breakaway" torque, which they do not specify. For example, an impact driver with a max torque rating of 200 lb ft cannot loosten a bolt that is at 200 lb ft, nor can it tighten one that tight. In fact it can only tighten to about 1/4 of that rating. Does anyone have any expertise on this issue? I am hoping to find one that can do lug bolts at about 80 lb ft, for around $200.00. It seems it is only a dream however.

compress ignite · #2 12-07-2010, 04:14 AM

1.Thou shalt not EVEN approach Lug Bolts with any sort of Impact Device.
1a.If it's too much trouble to Properly Torque 20 Lug Bolts(With a Torque Wrench),
sell the Mercedes to someone who CAN and just buy a Hyundai.

mpolli · #3 12-07-2010, 02:40 PM

Just want to loosten them.

DieselPaul · #4 12-07-2010, 02:49 PM

Be extremely careful if they are really on there THAT tight. Maybe try some penetrating oil. If it breaks off in the hub you'll have a crappy weekend. Someone brought me a 1998 C230 with lugs that had been impacted on, I took it back the Mr. Tire that practically welded them on and had them loosen them because it was so obnoxious, and if they broke it would be their problem.

kip Foss · #5 12-07-2010, 05:14 PM

My advice, after 67 years, 55 of those messing with mechanics, is to stay away from any kind of battery operated tool. They are handy but costly in the long run. I have worked all around the world, in the deserts of Arabia and the outback of Oz., and have rarely been in a position where I needed a battery operated tool.

My suggestion if you need an impact wrench is a 1/2 in. Ingersoll electric. They don't have the brute force of an air wrench but then in real life one rarely needs that kind of force. If so, that is the reason god made cheater pipes. You also don't have the cost of purchase and operation of an air compressor. You may already have a compressor but you can run an electric impact for a month on what it costs you to run a compressor for a day.

My Ingersoll is probably 30 years old and I have repaired it once. Any bolt/nut can be run down to the limit of the Ingersoll and the finished off with a torque wrench.

aklim · #6 12-07-2010, 05:48 PM

Quote:

Originally Posted by kip Foss

and have rarely been in a position where I needed a battery operated tool.

My suggestion if you need an impact wrench is a 1/2 in. Ingersoll electric.

Even guys use battery operated tools now and then.

It just might work better in certain positions if the female model is any guide.

How bulky is that electric unit?

kip Foss · #7 12-07-2010, 05:58 PM

Go to a store that sells tools and feel one. As I said, I don't doubt the advantage of a battery tool in some applications, but the overall cost through the life of the tool does not appeal to me. I have worked in industry for many many years and I look for the reliability in tools far more than the convenience.

strelnik · #8 12-07-2010, 06:09 PM

Quote:

Originally Posted by kip Foss

Go to a store that sells tools and feel one. As I said, I don't doubt the advantage of a battery tool in some applications, but the overall cost through the life of the tool does not appeal to me. I have worked in industry for many many years and I look for the reliability in tools far more than the convenience.

I am with Kip on this one, because I have one of those old Ingersoll impact wrenches! they are irreplaceable.

However, sometimes a Milwaukee cordless 3/4" drive comes in handy.

I have used it to run off lug bolts which I had loosened using generous doses of MAPP-gas heat and a 36" bar, CAREFULLY leveraged to avoid breaking anything/.

The impact is handy for keeping you from getting tired doing the bull work, then using strength in properly measured doses to TORQUE precisely.

I am looking for a Milwaulkee, but their advertisements and marketing are very confusing between types of batteries and chargers

Stoney · #9 12-07-2010, 06:56 PM

Quote:

Originally Posted by strelnik

I am with Kip on this one, because I have one of those old Ingersoll impact wrenches! they are irreplaceable.

However, sometimes a Milwaukee cordless 3/4" drive comes in handy.

I have used it to run off lug bolts which I had loosened using generous doses of MAPP-gas heat and a 36" bar, CAREFULLY leveraged to avoid breaking anything/.

The impact is handy for keeping you from getting tired doing the bull work, then using strength in properly measured doses to TORQUE precisely.

I am looking for a Milwaulkee, but their advertisements and marketing are very confusing between types of batteries and chargers

OK I have owned the Milwaukee 3/4" 28 Volt impact un for 2 years and have used it to change tires more than once on my ford truck, MB 300E and my PT Cruiser.

Ford truck in pouring rain next to nasty inner city interstate.
Loved it as 3 squirts of KROIL on each lug nut and a charged battery got all 5 nuts off and I was outa the hood in 15 min.
MB 300E I used it to pull the wheels after liberal squirts of KROIL but did not slam it on/off as I had no desire to snap a bolt.
PT Cruiser same tire change in the hood (1/4 mile from Ford truck flat) and it ate 1 wheel stud (snapped that sucker off quicker than a matchstick) even after KROIL. (well 1/2 tha parts are prolly Chinese!).

For use around the house (driving fence bolts and anchors into foundation) its quite good. For freeing up rusty bolts that you don't care about it is OK but trashes most grade 5 bolts. Very good on grade 8 bolts.

Battery life is OK but 2 or 3 batterys is best bet but they ain't cheap.

If I have the choice and 110V electric I will use my Dewalt 290 3/4" drive impact. It is good all around but it DOES NOT like working on a generator that is not a square wave voltage regulated machine (any Harbor Freight/Cambell Hausefield POS) Honda's and Lincoln/Miller, etc it works just fine.

I had IR Electric w/ skinny all metal body but it was wimpy on tought stuff.

Emmerich · #10 12-08-2010, 12:16 AM

Get a torque multiplier and ditch the cheater bars.

mpolli · #11 12-09-2010, 12:10 AM

Quote:

Originally Posted by strelnik

I am with Kip on this one, because I have one of those old Ingersoll impact wrenches! they are irreplaceable.

The impact is handy for keeping you from getting tired doing the bull work, then using strength in properly measured doses to TORQUE precisely.

Exactly... and I think I will take Kip's advice and go corded. Just don't really need to be cordless. Looking at a DeWalt rated at 345 lbft. Should be good enough.