Impact Driver of max 120 Nm won't undo 90Nm wheel bolt

[Sensibleboy]

Just bought a Erbauer impact driver with a max torque of 120Nm.

It won't undo a wheel bolt torqued to 90Nm. The clutch slips. It's not the motor that's too weedy.

I'm probably overlooking something but it doesn't seem right to me.

I can beat the clutch if I hold the socket in my hand. Does this sound normal?

My torque wrench set to 50Nm managed to undo the bolt that was tightened by the impact driver.

Edited by Sensibleboy on Saturday 8th September 11:29

[LarJammer]

Im guessing this is an electric one? What voltage? It may be able to torque up to that figure under perfect conditions but its the break off torque figure thats important. Usually to undo a bolt takes a larger torque figure than it was torqued up to.

[steveo3002]

b/s sales figures

ive got a 300+ one and sometimes it struggles , get yourself a proper one

[Sensibleboy]

It's an 18V model.

I suspected the break off requirement might be the issue.
I might take it back to the shop. I'll see if a replacement has the same characteristics.

I only got it to speed up assembly but it does seem a bit pathetic if it can only manage 50Nm.

Edited by Sensibleboy on Saturday 8th September 13:13

[Willy Nilly]

Does it look like this? https://www.screwfix.com/p/erbauer-eri6041pd-18v-2...

if so and I'll stand corrected, but that's not for doing wheel nuts up. You need an impact wrench this is the one I have and it keeps stripping the threads on the wheel studs on my self propelled sprayer http://www.makitauk.com/products/cordless-tools/im...

[robwilk]

Willy Nilly said:

Does it look like this? https://www.screwfix.com/p/erbauer-eri6041pd-18v-2...

if so and I'll stand corrected, but that's not for doing wheel nuts up. You need an impact wrench this is the one I have and it keeps stripping the threads on the wheel studs on my self propelled sprayer http://www.makitauk.com/products/cordless-tools/im...

+1 its for driving screws hence being called a driver, I have a dewalt cordless wrench and it has no bother with bolts on the car.
It the newer one, be carefull as the older models did not have the power of the newer bits of kit.

[Sensibleboy]

I didn't get it specifically for wheel bolts I just thought I'd see what it could do.

What's the 120Nm all about then if it can only actually tighten something to 50Nm?

[tapkaJohnD]

120Nm is about 88Ft-lbs, easily achievable with a wrench.
Get one and giove it some welly!

If you got the Impact driver because you vave a disability, then consider a "breaker bar", basicly a long wrench.

When retightening, an impact driver cannot be trusted to use the correct torque.
A torque wrench in this range isn't cheap (but neither is an impact driver), but a digital torque adaptor is half the price.

John

[Evolved]

You’ve bought a DIY screw impact driver, totally different bit of kit. You need a proper impact driver for car related work.

[Sensibleboy]

I bought it simply to save some time and effort. Putting an engine and suspension back in a car needs a lot of spanner work.

So should I expect an advertised 120Nm that only tightens to 50Nm to be reasonable?

I've got an impact wrench already and every other breaker bar, torque wrench etc so all that was missing was the impact driver.

[Evolved]

Sensibleboy said:

I bought it simply to save some time and effort. Putting an engine and suspension back in a car needs a lot of spanner work.

So should I expect an advertised 120Nm that only tightens to 50Nm to be reasonable?

I've got an impact wrench already and every other breaker bar, torque wrench etc so all that was missing was the impact driver.

Accept it or not, it’s the wrong tool for the job you’ve bought it for. You need a car specific tool. That is intended to drive screws into wood!
If you’re not happy, take it back and refund, then buy a proper one.

[Sheepshanks]

Sensibleboy said:

I didn't get it specifically for wheel bolts I just thought I'd see what it could do.

What's the 120Nm all about then if it can only actually tighten something to 50Nm?

I don't know why this happens but apparently you lose torque in the adapter to the wheel nut socket.

[anonymous-user]

I got one of these electric cabled ones and it's managed everything except the crankshaft bolt on a Volvo engine.

https://www.machinemart.co.uk/p/clarke-cew1000-ele...

[Jakg]

Just because it doesn't undo wheel nuts, doesn't mean it's necessarily useless.

For lower torque stuff it will come in handy and there are some things that the impact nature will undo better than pure torque on a breaker bar or similar, especially in awkward spaces.

I crack off all my wheel nuts with a breaker bar and then use an impact driver to remove them and refit them and then just go round with a torque wrench at the end. Much much quicker than by hand.

[freecar]

There appears to be some confusion here.

Impact driver, for screws, not bolts, anything else will kill it very quickly. (has 1.4" hex drive)

Impact wrench, for nuts and bolts, 400Nm would be the minimum useful torque for wheelnuts and such but more is better. (has 3/8" 1/2" or 3/4" drive)

Breakaway torque is a meaningless figure with no real world application, ignore this and rely on the working torque figure.

Battery ones are OK, air is so much better with more power in a smaller tool but you of course need a compressor and quite a big one if you want to use high power impact wrenches as they need a lot of air!

[Willy Nilly]

freecar said:

Battery ones are OK, air is so much better with more power in a smaller tool but you of course need a compressor and quite a big one if you want to use high power impact wrenches as they need a lot of air!

My Makita 1/2 inch drive impact wrench scoffs at what our CP 1/2 inch drive air impact gun won't even look at. There's scaffolders at work at the moment and they each have one of the smaller Makita impact wrenches

[PhillipM]

We've got 3 of the makita's, even the tiny brushless one that you can get in engine bays, etc, will happily crack off 40mm hub nuts.

The big 1002Z will quite happily snap M18 12.9 bolts for breakfast if they're stuck.

[freecar]

Willy Nilly said:

My Makita 1/2 inch drive impact wrench scoffs at what our CP 1/2 inch drive air impact gun won't even look at. There's scaffolders at work at the moment and they each have one of the smaller Makita impact wrenches

I didn't say a st air wrench would be better than a DC one, but size for size you can get a lot more power (like more than double) from a decent air wrench with the right hose and compressor than even the most expensive DC one of the same size.

I source these things for a living and have seen more samples than most have had hot dinners!!

[Willy Nilly]

freecar said:

Willy Nilly said:

My Makita 1/2 inch drive impact wrench scoffs at what our CP 1/2 inch drive air impact gun won't even look at. There's scaffolders at work at the moment and they each have one of the smaller Makita impact wrenches

I didn't say a st air wrench would be better than a DC one, but size for size you can get a lot more power (like more than double) from a decent air wrench with the right hose and compressor than even the most expensive DC one of the same size.

I source these things for a living and have seen more samples than most have had hot dinners!!

Which air impact wrench should I have bought?

This one https://www.cp.com/en-uk/tools/products/impactwren... has quite a bit less torque, getting on for half, that my Makita DTW1002 has.

So far, the Makita is undefeated, the biggest issue I now have is stopping it before it strips the threads on the bolts. I've not used the air wrench since I bought the cordless.

[freecar]

Willy Nilly said:

freecar said:

Willy Nilly said:

My Makita 1/2 inch drive impact wrench scoffs at what our CP 1/2 inch drive air impact gun won't even look at. There's scaffolders at work at the moment and they each have one of the smaller Makita impact wrenches

I didn't say a st air wrench would be better than a DC one, but size for size you can get a lot more power (like more than double) from a decent air wrench with the right hose and compressor than even the most expensive DC one of the same size.

I source these things for a living and have seen more samples than most have had hot dinners!!

Which air impact wrench should I have bought?

This one https://www.cp.com/en-uk/tools/products/impactwren... has quite a bit less torque, getting on for half, that my Makita DTW1002 has.

So far, the Makita is undefeated, the biggest issue I now have is stopping it before it strips the threads on the bolts. I've not used the air wrench since I bought the cordless.

Difficult question as air tools have a habit of needing more than just buying and using.

https://www.amazon.co.uk/Facom-NS-1600F-Pneumatic-...

Is only 4" from front to back so you can see that it would get into places that cordless cannot dare! However if the airline bore is too small, the compressor not man enough to flow that much air or the fitting being poor quality and not free flowing then it will not reach it's specified torque value.

DC on the other hand will achieve it's working torque with a fully charged battery nothing more complex than that. But to get truly large torque figures you are looking at a sizable motor, with air all you need is the hammer, the air does the rest. Watch a few teardowns and you'll see how simple the air ones are compared to DC.

If access is no problem, a good DC machine is a far superior piece of kit, not needing an airline gives more flexibility. For out and out power air is where it's at but at a cost of other expensive machinery.