Electric impact wrench?

Anybody have any opinions about electric impact wrenches, and this one in particular from Canadian Tire?

Mastercraft Maximum Impact Wrench with Digital Display | Canadian Tire

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I'm thinking it might be useful for changing to and from winter tires, and not have to pay for the semi-annual tire change fee. It's on sale right now, and it seems at this price it'll pay itself off in 3 tire change seasons with one car, even quicker with more of them.

Yousuf Khan

Reply to
Yousuf Khan
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Opinion: if the wheels aren't over-tightened when they are installed they shouldn't be difficult to remove. In other words, if you don't use an impact wrench putting them on, one shouldn't be required to get them off. Think about it -- if you are on the road and get a flat, how are you going to put on the spare if some whackjob has torqued the lug nuts with a power tool? Just tighten to the recommended torque and you should be golden. On the other hand, if you are just looking for an excuse to buy a tool, a perfectly normal male obsession, go for it. (just don't get carried away tightening things you might have to loosen manually)

Reply to
John McGaw

Rest of above link snipped. Either Thunderbird or AIOE wouldn't allow it.

I prefer the impacts with the hog ring on the end to hold the sockets on the wrench. Swapping sockets is easier with those than the impacts with the tit on the end. It probably won't matter for your use.

Reply to
Dean Hoffman

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80 ft lbs with a wrench is exactly the same as 80 ft lb with an impact. And the impact is a lot easier than spinning all the nuts by hand.
Reply to
clare

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Assuming the impact wrench is accurate. This one doesn't mention its calibration (and that its traceable to NIST standards) or accuracy, like

+/-5% with +/-2% repeatability.

Having a torque-regulated impact wrench doesn't obviate the need for a torque wrench. You still use a torque wrench after using an impact wrench to spin on the nuts to ensure they are at the specified value. The impact wrench is used for fast setup: quick removal (instead of requiring muscle power to "break" the nut free) and quick install. Its torque setting is meant only to get you close to but under the desired torque, not to be dead on. If you want to ensure the nut is at specified torque, you use a calibrated torque wrench after using an impact wrench.

An impact wrench with built-in torque control is only used to snug a fastener somewhere close to the desired torque. Don't rely on it being accurate. Under torque using the impact wrench (to ensure you don't end up over torquing) and finish with a torque wrench to bring up the torque. Using an impact wrench set right at the target torque value means you end up over torquing, as John mentioned.

From what I remember, the recommended torque depends on bolt size and the following chart is typical:

Bolt Size Torque Range (ft-lbs)

12 x 1.5 mm 70 - 80 12 x 1.25 mm 70 - 80 14 x 1.5 mm 85 - 90 14 x 1.25 mm 85 - 90 7/16 in. 70 - 80 1/2 in. 75 - 85 9/16 in. 135 - 145

Note the *minimum* torque range of this impact wrench is 80 ft-pounds. For wheel nuts, a range is specified, like 70-80 ft-lbs. You want to be somewhere in that range but not outside of it. This impact wrench's lowest setting is 80 ft-lbs which is at the top of the range for some lug nuts. Except at 85 ft-lbs, or more, your lug nuts will end up over torqued using this impact wrench. Doesn't look like a good unit to be using for wheel nuts. The bottom of its range (likely to be even less accurate) is at or exceeds the top of the range for the lug nuts.

Just because car shops only use an impact wrench to slap on your wheels doesn't mean that's how you should do it properly. Use the impact wrench to under torque and then a torque wrench to bring up to torque. The shops have "slop" to cover their damage and may have to do repairs but do you as a hobbyist really want to replace a stretched wheel stud? Yes, it's easy to replace a wheel stud but why not get an impact wrench with torque setting BELOW the BOTTOM torque range of the lug nuts? Otherwise, what's the point of paying extra for the built-in torque control with digital display if you're going to have to manually use the impact wrench to under torque by feel (and then follow with a torque wrench)?

Since we're talking about a hobbyist here that does a wheel change twice per year rather than a tire shop doing it several times each day, and since a torque wrench is needed after using the impact wrench, why bother with the impact wrench? Just use the torque wrench alone. Yeah, that won't satisfy the male urge to amass a collection of rarely used tools. The impact wrench will save time, yes, but do you care about saving 2 minutes per year? You still start the nuts by hand and you still use the torque wrench at the end so the only time you save is using the impact wrench to spin on the lug nuts instead of using an x-wrench to spin them on. You'll probably waste that much time, or more, digging out the impact wrench, snapping on the socket, and stringing out an extension cord.

If you, er, Yosuf really wants that impact wrench experience and needs to collect tools for the sake of doing so, get a compressor with big tank, regulator, and pneumatic impact wrench so you get the full experience. The rattling alone of the socket against the nut using an electric just isn't the same without that wheesh, wheesh, wheesh noise of a pneumatic to impress your neighbors.

A torque wrench and x-wrench is all Yousuf needs. An impact wrench (with or without built-in torque) is just another tool toy. It makes sense for a car shop using it several times every day but doesn't make sense for one person changing their wheels just twice per year. Personally I figure grabbing an x-wrench off the nearby wall hooks to spin on the lug nuts would be a lot easier than having to dig out an electric impact wrench, find and snap on the right-sized socket, string out an extension cord, and then stow it all away again afterward. When I put up siding on a house or build the framing for a garage, yeah, stringing out an extension cord, pulling out the compressor, hose, and pneumatic nail gun makes sense. It doesn't make sense when all I need is a hammer to put a nail in the wall to hang a picture. For what Yousuf described, he is changing wheels twice per year and on one vehicle. An impact wrench is overkill. Get an x-wrench (aka 4-way lug wrench) for $20 and spin on the lug nuts. Works even during a power outage, when no power is available, or toss in your trunk to use on the road. If Yousuf doesn't have a torque wrench, he will need one whether he uses an x-wrench or impact wrench.

Reply to
VanguardLH

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I LOVE the one I bought from Lowes, Kobalt brand. Wish I had got one

30 years ago! It is nice for wheels, but I've used it now for struts and transverse link bushings.
Reply to
1 Lucky Texan

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If the electric wrench is anything like a good air wrench, with experience you can get those nuts within 5 ft lbs of the desired torque EVERY TIME. With my old CP 934 and 125 psi line pressure, 4 hits was 80 foot lbs, every time. I checked with the torque wrench and it never varied more than 5 lbs. My apprentices and mechanics could never figure it out. Got to the point I had to threaten to ban the impact if I heard anyone let their impact hit at all when installing rims. I did (as service manager) spot check vehicles for torque on jobs that involved removal/replacement of rims - and the guys never knew which car was going to be checked - which wheel, or when.

The beauty of the impact is it makes running the nuts on and off speedy and effortless - with the bonus of being able to rattle tight stuff loose with less chance of twisting off fasteners.

Reply to
clare

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Yep, you're talking about a shop using an impact wrench every day and getting quite used to just how much to rotate on each use. You really think someone swapping their wheels twice a year is going to have the expertise? Being with 5 ft-lbs is great if you know that you don't gov over the torque spec or can under torque to tweak it off with a torque wrench ... but just how is an impact wrench whose BOTTOM range is 80 ft-lbs going to get within 5 ft-lbs and still be at 80 ft-lbs? With a 5 ft-lb leeway, the twice-a-year user is going be over torquing above 80 ft-lbs.

You're talking about an impact wrench that has the proper range for the task and expertise in using it that the OP won't have. Considering who asked, he needs to under torque and then bring it up ... and the unit he asked about would certainly end up over torquing most of the time if he goes by the low end setting of that unit to torque at the high end for the lug nuts. I'm sure he could figure out how to under torque with that unit by feel (and then using a torque wrench to check how far he got) but I doubt he'll be practicing that much and then it was a waste of money to get the in-built torque with digital display. Since he'll be bring up the under torqued nut with a torque wrench, he might've as well as started with that.

As for quick on and off, who cares for just twice per year of swapping wheels on one vehicle? Like I said, and since he's not a shop that will have a constant setup, the time to setup to use the impact wrench and stow it all afterward is longer than spinning on the nuts with an x-wrench. Yeah, it's fast AFTER you're setup but not faster overall for a twice-a-year use.

Reply to
VanguardLH

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True, but it is not the tool's fault. As for changing the wheels spring and fall I still have 12 wheels to change twice a year - and with aging achy joints the impact wrench would still make it a lot easier - but I only have the air wrench -and getting aired up and all the hoses out is a lot of hassle - so I generally do it all by hand. I did buy an electric impact a couple of years ago but it was a useless cheap chinese 12 volt hunk of crap and I quickly returned it.

Reply to
clare

I should have been a little more clear, so far, I have only used the impact for removing; wheel nuts, lower strut bolts, half-axle nuts, transverse link mount nuts. Those were all tightened with a torque wrench.

The ONLY time I've used the impact in forwards direction was for the spring compressors I borrowed from AutoZone.

But, I admire someone being able to install stuff with one without over-torquing, just, I may not ever be that good with it.

Reply to
1 Lucky Texan

Also my thinking. This wrench is supposed to have some kind of torque sensor on it. My original question was trying to determine whether anybody else has this or a similar impact wrench, and what they think of it. Like for example is the torque settings accurate enough? Whether the wrench itself is reliable, etc.?

Yousuf Khan

Reply to
Yousuf Khan

You didn't quite understand the question properly. I'm not talking about changing one tire at a random interval, but all 4 tires at well-defined intervals, i.e. in the winter and in the spring.

Yousuf Khan

Reply to
Yousuf Khan

Over here, due to the fact that we do have standard set intervals for tire changes, the shops usually overcharge around $35 per session up here. That's $35 in the winter and another $35 in the spring. And I got two cars to do it on, which is double the price again. Although saying that it's a simple matter of just using hand wrenches to do it, but you don't know how cold it gets up here. By November, it's too cold to go out without gloves, and taking gloves off while changing the tires is excruciating; even now in October it's pretty bad. In the spring, it's getting warmer, but there's a lot of slush around usually which makes it dirty, and the bolts would have a bit of rust on them too which makes it a bit harder to take off.

Yousuf Khan

Reply to
Yousuf Khan

Yeah, I got 8 wheels here to change. I've been reading some of the reviews on the Canadian Tire reviews section. Seems to be getting a lot extreme mixed reviews. Those who love it, love it, and those who hate it hate it. Very few in between reviews, either 1's or 5's. The few in-between reviews mention that they don't trust the torque calibration.

Yousuf Khan

Reply to
Yousuf Khan

I wish I knew what you were talking about, it sounds like fun. :)

Yousuf Khan

Reply to
Yousuf Khan

This wrench is adjustable in 5 ft-lb increments. The low end of its range is 80 ft-lbs. Likely the *top* range for your lug nuts is 80 ft-lbs (see the table in my other post). They don't specify accuracy. You won't know if you're over torquing unless you follow with a torque wrench; however, because this unit's bottom end is 80 ft-lbs, you cannot under torque and polish off with the torque wrench to bring it up to

70-80 ft-lbs.

Don't impact wrenches come in models that would *span* or encompass the torque range for wheel lug nuts, like 65-150 ft-lbs?

Reply to
VanguardLH

tit = Small ball bearing with spring behind it in the square nub that goes into the socket. It holds the socket onto the nub.

For an image, look at the impact wrench you asked about. It has the tit style. Think of what a regular socket wrench looks like. If the ball bearing gets rusty, dirty, or damage, it may not move into the recess so you cannot put on sockets or it may get stuck inside the recess (and you cannot pull it out) so sockets won't stay on. If rusty, you might be able to use penetrating oil to free the ball bearing. If physically damaged, it'll stay stuck.

hog ring = Holds the socket onto the nub using friction or uses indents machined into the sockets.

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Easy 'nuff to lube the ring or replace it. Most times when I've looked at impact wrenches, they only not the "ring" style for holding on the socket. Hog rings are, in fact, used for something else, like holding upholstery: they're u-shaped band of metal that, with appropriate pliers, are bent to form a ring around multiple objects or the fabric you wish to fasten (bunch) together. The rings on impact wrenches look more like retaining rings.

Reply to
VanguardLH

They all do - but most do not have any digital readout.

Reply to
clare

The one Yousuf asked about (electric, not pneumatic) states:

"Digital control: push-button control of torque in 5 ft-lb increments (80-350 ft-lbs)"

Presumably that means the in-built spring mechanism won't release (click off) until the minimum of 80 ft-lbs is reached. With 5% accuracy (which is being gracious), a setting at 80 ft-lbs, the minimum setting, could end up with the lug nut torqued at 84 ft-lbs. The worst the accuracy then the more over torqued the lug nut might be (or under torqued). Sorry, but an impact wrench with a spec'ed torque range of 80 to 350 ft-lbs is not spanning the 70-80 ft-lb range for lug nuts. This is not one of those "they all do" models.

While this unit will probably end up over torquing the lug nuts, it won't be by much. I doubt 85 ft-lbs on an 80 ft-lb spec'ed bolt is going to stretch it. Thankfully the target for torquing can be easily repaired as replacing a lug bolt is pretty simple. The point of spending the money on one with a digital display where you can set a specific torque means you'll be relying on that setting; however, for this model, the lowest setting is at the top of the target range. This one doesn't seem to be one of those "they all do" models that would span the torque range for lug nuts. Maybe, as you mentioned, Yousuf could go by feel assuming twice per year on 8 wheels gives him the "feel" expertise but I suspect he'll have to discard the digital torque setting, go by feel to under torque, and then use a torque wrench to bring it up within the correct range. He won't be using the digital display or torque click-off settings but instead just us the electric wrench to quickly spin on the lug nuts. With this unit, he'll still need a torque wrench.

If ignoring the digital setting and using "feel" (which you may have practiced expertise but not Yousuf) to determine when close to the specified torque, how do you know you really are at the specified torque? You can assume your guess was close enough but even folks playing horseshoes want to *see* where are the horseshoes. To see where the "feel" brought you for torque, and since the digital display is out of range for the torque setting, just how is Yousuf going to *see* what is the torque on the lug nuts?

The other problem is with the "Mastercraft" brand. Not all Mastercraft tools are made by the same manufacturer and every so often they change their suppliers (i.e., who supplies the actual product to them so they can stamp or label it as "Mastercraft"). Last I heard, WMH Tool Group makes the majority of CT's power tools, including the Mastercraft, Mastercraft Maximum, and Jobmate brands. Quality isn't consistent across the product line or even by product as suppliers get changed. You get makers of hand tools producing good products but not all the hand tools under the Mastercraft brand are coming from that same good manufacturer. WMH makes the MC Maximum 10" slider cms while GMC makes the MC Maxmimum circular saw. Different suppliers, different qualities. Some are good (for now until the supplier changes), some are lemons, so you can't use the "Mastercraft" brand to tell you anything about quality. It's like soup du jour: might've been good on Monday but the same soup on Thursday is terrible because the soup cook on Thursday isn't the one you got on Monday. Mastercraft is a blanket brand under which tools are contracted for production and which come from different suppliers that change over time.

With the unit proposed by Yousuf, I really think he needs to consider getting a torque wrench; else, he is hoping that repeated over torquing is too little to care about and won't have him replacing stretched or stripped lug bolts.

Reply to
VanguardLH

Talk about painting the bike shed. Get a breaker bar, speed wrench and torque wrench. Your fingers will only touch the wheel nut when you first feed it on by hand, which you are going to do anyway. Wear gloves and you are done.

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Reply to
Rasco Coltrain

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