Impact wrenches and their torque ratings

[Gad-Westy]

I have fancied getting an impact wrench for some time now. Either 3/8 or 1/2". The rated max torque figures seems to vary massively.

I have Hitachi/Hikoki power tools so have a few of their 18v LiIon batteries but the only Hikoki impact wrench I can see seems to have a max torque figure of 305Nm. That doesn't sound a great deal to me and I'm certain I normally have to use more torque than to crack an overtightened wheel nut. However it seems to win quite a few group tests and would be nice to keep same battery system.

Another contender on my list is a dewalt xr model that boasts a max torque of 950Nm and isn't actually that much more expensive. In the real world can the Dewalt really be more than 3x as effective? If so, I'm sold.

[normalbloke]

The Milwaukee 1/2” drive runs to about 1700nm, the 1” drive runs to about 2400nm. Both 18v.

[The Road Crew]

I can only speak for the dewalt. I have the 1/2" dcf899 and it's a monster.
Hub nuts, wheel nuts, suspension, crank pulley bolts are all no problem.

Only downside is its size/weight. It's not easy to handle. I have a smaller 3/8" dewalt for lower torque fasteners, much easier to work with. It's useless on wheel nuts, crank bolts etc though, that's where the 899 comes into its own.

[Dave.]

I have a kielder 1/2”, should be 430nm, but it struggles with wheelnuts to be honest. It’ll get them off eventually, but takes a good few ugga-duggas.

They do a 700nm one now too.

Thing is, how can you test them?

[Gad-Westy]

950nm Dewalt is maybe sounding like a decent option then. It can be had with two batteries for £260 which seems good value and I guess I could pick up a smaller model 'naked' for not too much money later on if it seems like it would be useful.

[Dave.]

Check the dimensions of it beforehand.

If it’s just for wheelnuts it’s irrelevant, but if your wanting it for suspension bolts, you might want a smaller one.

There’s a bit of a trade off between size and power.

Then have a look in the tools thread at the angle impact wrench....

[Evoluzione]

Dave. said:

Thing is, how can you test them?

Torque a wheelnut up with a torque wrench and see what happens.




IME if it's got an airline hanging out the back of it and it takes two hands to pick it up you won't go short.

[darreni]

I have the dewalt 899, I bought it specifically for hub nuts, wheel bolts & suspension bits.

So far it’s been great.

[Dave.]

Evoluzione said:

Torque a wheelnut up with a torque wrench and see what happens.

To 430nm? :hehe;

[Sanchez89]

Everything I have read or seen on the cordless impact wrench scene, I would buy the 18v 1/2 Milwaukee gun. Seems to whip everything off in short order, I have the 3/8 stubby version and it's a bit of a weapon with the 4ah battery. Wheel nuts are no bother.

[Gad-Westy]

Sanchez89 said:

Everything I have read or seen on the cordless impact wrench scene, I would buy the 18v 1/2 Milwaukee gun. Seems to whip everything off in short order, I have the 3/8 stubby version and it's a bit of a weapon with the 4ah battery. Wheel nuts are no bother.

Which model numbers please? Seems to be a few options.

[Evoluzione]

Dave. said:

Evoluzione said:

Torque a wheelnut up with a torque wrench and see what happens.

To 430nm? :hehe;

Then try a different nut. You certainly don't torque hub centre nuts or head bolts up with a 450Nm torque wrench, yet many can not be undone with an average half decent impact wrench.

[Dave.]

Evoluzione said:

You certainly don't torque hub centre nuts or head bolts up with a 450Nm torque wrench, yet many can not be undone with an average half decent impact wrench.

That's what I was getting at, you can't test them by torquing up a bolt and seeing if a rattle gun will get it off.

I did see a video of the kielder one being tested, but I doubt that it's available/accessible to the general public.

Edit - this one.... https://youtu.be/6sV1dGqNhcY

Edited by Dave. on Saturday 21st November 13:22

[kambites]

I think mine is rated to 680NM and it's shifted everything... until last week when I tried to get a rear brake caliper hanger off the Skoda. That might be because of the flex in the 2 foot extension rod I'm having to use to get at it, though. To be fair to the wrench, even dropping the weight of the car onto a 3 foot breaker bar wont budget the damned things.

[InitialDave]

I have the Dewalt 899, and yes, its very effective, rare for me to encounter something I need to do manually instead. Would recommend.

[Gad-Westy]

InitialDave said:

I have the Dewalt 899, and yes, its very effective, rare for me to encounter something I need to do manually instead. Would recommend.

I think this is where I'm leaning. Looked at the milwaukee options and I'm sure they're fantastic but nearly twice the price.

[InitialDave]

If you can hold off, I got mine from FFX tools on Ebay, who are subject to an ebay 20% off coupon on a semi-regular basis, which makes them a really good price. Unfortunately you've just missed one this past week, but there'll probably be another along soon.

[Gad-Westy]

InitialDave said:

If you can hold off, I got mine from FFX tools on Ebay, who are subject to an ebay 20% off coupon on a semi-regular basis, which makes them a really good price. Unfortunately you've just missed one this past week, but there'll probably be another along soon.

Cheers. Just taken a look. With 20% off they come in a bout £6 cheaper that Zoro tools so not really a deal breaker but will keep any eye out.

[InitialDave]

Ah, yeah, looks like maybe the price has changed since j ordered mine, I think I paid £250, and Zoro shows as £260, so no different really.

[Gad-Westy]

InitialDave said:

Ah, yeah, looks like maybe the price has changed since j ordered mine, I think I paid £250, and Zoro shows as £260, so no different really.

It seems like a great buy given it has two batteries as well. I could get a small low torque version body only for £110 as well and have a really nice little set up for less that £400. Might need to have a word with Santa and see if I've not been too appalling this year.