Impact wrench

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Old 03-10-04, 01:23 PM
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criecke
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Impact wrench

New to this type wrench.

How do you control torque you are putting on the nut.

In short how do you know when to stop holding the trigger,
if you just hold it does the torque just keep building or
can you set a release point.

Charlie Johns Island, SC [email protected]
 
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Old 03-11-04, 05:15 AM
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criecke:

All impact wrenches I am familiar with have a knob near the inlet connection you can rotate to increase/decrease the amount of torque the tool will apply.
Judgement based on experience is how most determine when a fastener is tight enough.
The best way is to use a torque wrench to see how much force yours can apply.
Some nuts, particularly wheel nuts are considered a safety hazard if not torqued properly. Other fasteners can be broken off or distort the thing you are tightening if not done correctly.
In some cases you will need to use judgement to decide if an impact should be used.
In other cases, like with a wheel nut you can do an initial tighten with an impact wrench but must use a torque wrench to verify manufacturers specs. Reputable tire shops do this or use a calibrated torque adapter on their impacts.

Put a number of bolts in a vice and use a torque wrench to see what yours can do.
 
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Old 03-11-04, 09:55 AM
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IMO, an impact wrench should be used ONLY for removing bolts and nuts, not installing. There's just no way to reliably predict how much the wrench is going to apply, it depends on air pressure, tool condition, use of an extention or not, bolt/nut type and if it's been lubricated, etc.

This is especially true when working with lug nuts. You can strip or break wheel studs or even crack wheel rims by installing lug nuts with an impact wrench, and just as important, you're not going to have that impact wrench with you at 2am on the side of the interstate to remove that lug nut that was over-tightened by the impact wrench.

Some high end impact wrenchs can apply 1200+ lbs of torque, even the low ends are in the 200 area. Most lug nuts only need about 90.
 
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Old 03-11-04, 09:59 AM
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Pens right on with the lug nuts.

If your not used to it or not ready you'll cause yourself some work. I've got an electric Milwaukee impact and there is no adjustment. If you don't know what your doing you can snap a bolt real quick.
 
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Old 03-11-04, 11:21 AM
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i've seen

mechanics use a torque adapter when putting lug nuts on. It looks like a socket extension and is calibrated to limit the torque to a certain ft-lbs number. I guess you could also adjust air pressure or the torque knob that Greg mentioned, but I've never seen a mechanic mess with any controls, it's just faster and easier to snap a limiter in & out.
 
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Old 03-11-04, 11:54 AM
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criecke
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Impact wrench

Thanks to all for the info.

Question: how does the "limiter" limit.

Can you comment on this - I read somewere that if you
tighten a nut/bolt with a regular wrench and then use the
torque wrench to make the final tighting you will not end
up with the torque you think you have.

I think what they are getting at is that with the torque
wrench you should go about half way first and then go
the rest of the way with a steady motion and stop on
the torque value you want.

I have only been to one tire store that finished with a
torque wrench, the others just pulled the trigger and
"brerzzzzzz" and on to the next lug nut.

This just came to me, does it take the same torque to
take lug nuts off as to put them on?

Charlie
 
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Old 03-11-04, 01:06 PM
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www.torquestick.com

I have no idea how they are designed and built, maybe the above site will help. That's what my buddy, who is a Chevy tech, uses.
 
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Old 03-11-04, 05:14 PM
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The impact torque adapter I'm familiar with looks like a short extension with about a 2" barrel. It can be adjusted for different torque levels and breaks away when the torque is reached.

Tire shops that don't torque wheel nuts imo are just displaying their lack of professionalism. I know that with experience one can come pretty close to proper spec by using a hand tool. If something were to happen though and a wheel problem were the fault of an accident, the mechanic that was seen by the customer spinning lug nuts on with a torque wrench, would get hammered in court.

I'm really lazy when it comes to spinning nuts and bolts.
What works for me is that I put on most fasteners with the 1/2" impact on low and finish up by hand.

Charlie:
I still think that if you are expanding your tool horizons with a new impact, a torque wrench would be a good investment if you don't already have one.

Get a fistfull of old nuts and bolts and see what it takes to twist them apart.

An interesting site with torque info.
 
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Old 03-11-04, 05:39 PM
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criecke
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Impact Wrench

Markiz 37 and Greg H

Info you both sent is just what I was looking for,making
up an order for Torque Sticks when I sign off here.

Then reading wrench sheet.

Thanks to both of you for your time,patience and
knowledge. Charlie
 
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