Air impact wrench

I bought an air impact wrench from me local shop the other day. Back of the box states 345nm of torque, requires 6 bar compressor, i have 8, 2.5hp engine, which i have, and all the other bits and bobs comply with the compressor i have. However, upon testing, it wouldn't undo a wheel nut. I then torqued it up to 210nm, and it would not undo that either. So either the back of the box is a lying prick, or am i doing something wrong?
Didn't mention brand: it's a mecafer one.

does it if you hold trigger for a while,what bore pipe and fittings are you using,,though ive allways found gun manufacturers and compressor manufactures exaggerate

Has it got a little wheel on the bottom like mine that alters the torque?

Cheapo air impact guns are rubbish, I have the same kind of setup as you and I've tried (bought?) a few cheapo ones and they wouldn't undo anything remotely tight, then I borrowed an Ingersol Rand gun and that was a whole world away, that did what I expected.

ProcrastinatorFraser said:

I bought an air impact wrench from me local shop the other day. Back of the box states 345nm of torque, requires 6 bar compressor, i have 8, 2.5hp engine, which i have, and all the other bits and bobs comply with the compressor i have. However, upon testing, it wouldn't undo a wheel nut. I then torqued it up to 210nm, and it would not undo that either. So either the back of the box is a lying prick, or am i doing something wrong?
Didn't mention brand: it's a mecafer one.

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That is a rather weak impact wrench. you using 3/8 inside dia air hose or the 1/4 stuff?

I've got a 20 quid one from aldi and that undoes most things on mine

Christ thanks for the replies. I don't know about the hose dia. Alls i know is that i tried 2 hoses to no avail. It does have a spinny bit on the bottom which i have set to pos. 4 which according to the manual is max.
When i hold the trigger for a while it ****es me off more and not much else.

My advice would be to take it back and buy something decent instead from cp or Ingersoll (not the plastic fantastic varieties)
https://www.google.co.uk/shopping/p...d=0ahUKEwjEsKGzl7XKAhUF1BoKHTaODZAQ8wIIwgEwAA

You also need to check the flow capability of your compressor and flow requirement of the wrench (cfm) and as others have said, 3/8 to 1/2" hose and none restrictive fittings. But tbh you wont be far wrong, the box is a lying prick

I found the same and ended up with a battery one that is incredible! The air impact and 3/8 ratchet are in the naughty corner of the garage!

ProcrastinatorFraser said:

I bought an air impact wrench from me local shop the other day. Back of the box states 345nm of torque, requires 6 bar compressor, i have 8, 2.5hp engine, which i have, and all the other bits and bobs comply with the compressor i have. However, upon testing, it wouldn't undo a wheel nut. I then torqued it up to 210nm, and it would not undo that either. So either the back of the box is a lying prick, or am i doing something wrong?
Didn't mention brand: it's a mecafer one.

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It will be the case of the misleading box! You will discover they have taken that torque reading in a lab and the PEAK torque the gauge read probably was 345Nm for an instant, not sustained. We can all apply more force for a instant than we can sustained - the cheeky sods will have used this as their reading.

Big bore pipe helps, add a big dollop of oil into the air line connection before you use it, you are meant to oil them anyway, I used proper air tool oil on mine and in the end added some motor oil, did make it more punchy.

In the end got a Makita cordless one.. WOW!

I've got an old snap on one, not usually a big snap on fan ( over priced in my opinion) but this does what it says on the box.

Well thanks guys, discomania, that will probably be the case.
What sort of oil am i meant to be using? the manual said nowt but i've looked it up and apparently wd40 works quite well, what do you use?

Pull the trigger while squirting wd40 down the inlet before and after use. Put a cap full of engine oil in the hose frequency depending on usage, it takes a while to trickle through so a cap full lasts a while.
This won't make a cheap gun better, but will keep it running at its best

trax99 said:

I've got an old snap on one, not usually a big snap on fan ( over priced in my opinion) but this does what it says on the box.

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Snap on used to rebadge Ingersoll Rand guns and price £110 guns at £170 with their name on so over priced is right. have their own made these days I believe

cooltide said:

Pull the trigger while squirting wd40 down the inlet before and after use. Put a cap full of engine oil in the hose frequency depending on usage, it takes a while to trickle through so a cap full lasts a while.
This won't make a cheap gun better, but will keep it running at its best

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use proper air tool oil. engine oil will gum up your air tools. Don't be a tool

Had an idea you'd be the next to post fûcknuts, but if you have the luxury of an inline oiler reservoir, the redneck has a point

I've told you before I use nut guns for a living,

Thor1950 said:

use proper air tool oil. engine oil will gum up your air tools. Don't be a tool

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Told you before I use nut guns for a living. Engine oil in sensible quantities doesn't bother impact wrenches. It does bother pile drivers and breakers. Go play with your nuts

Hi, I work in a power tool shop and supply compressors and nutt guns to trade. What size tank is on yours ?. That set up is old school now due to how much battery power has progressed, we recommend a min 150 Lt tank and three horse for nutt spinners and a gun rated to 650nm to take wheel nuts off. There is a battery powered 18v that will in reverse delivers 1735nm and 950nm forward. We had a local garage test it and they could not believe the power, this thing removed lorry wheel nuts with no effort. I'm unsure of what i can say brands ect as I'm new to the forum and don't want to cross any boundaries.

Spamming is frowned upon so as long as you aren't sole Irish distributor....