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So I purchased a Milwaukee 2663-20 to work on my future car. With 450 ft-lbs of torque advertsied, I figured it would be nice to unbolt hard bolts if required.
I was reading the back of the box and noticed the breakaway torque is actually much higher, 640 ft-lbs. So this means if I would hypothetically torque something to 640 ft-lbs I could undo it with this?
My understanding of it is that your hypothetical is true.
Yes
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Be ready for a lot of hammering lol.
Bremon wrote:
1 hour ago, Bremon said:Be ready for a lot of hammering lol.
JimboS1ice wrote:
6 hours ago, JimboS1ice said:Yes
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rbacon705 wrote:
9 hours ago, rbacon705 said:My understanding of it is that your hypothetical is true.
Great thanks!
,,,If it has been torqued to that by other means then an impact wrench that is
kornomaniac wrote:
1 hour ago, kornomaniac said:,,,If it has been torqued to that by other means then an impact wrench that is
Why? If something is torqued to X value with a torque wrench or somehing else it will be the same torque.
Hypothetically, probably not. There’s a lot of variables. If you had ideal material conditions and an ideal way to apply constant torque to tighten it and bring it up to 650 ft/lbs then you would have a bolt torqued to 650 ft/lbs. The breakaway torque required to get a fastener with a static load moving again in the opposite direction is generally higher than the torque that was applied to a moving fastener in the other direction. What does 650 ft/lbs equate to as far as how high a bolt was torqued to? I dunno. All that spec means is that it will put out 650 ft/lbs of torque in reverse. So enough for fasteners on a light duty vehicle.
TheMidnightNarwhal wrote:
12 hours ago, TheMidnightNarwhal said:
Why? If something is torqued to X value with a torque wrench or somehing else it will be the same torque.
What stercorius above me said. There is a difference between torque put on a bolt with an impact wrench and torque you put on with a manual torque wrench.
Sterco is correct. There is a difference in breakaway torque and the torque applied in tightening. Breakaway torque is the maximum initial force applied when busting a fastener loose. I’m no engineer, but as I understand it, it can take like twice as much breakaway torque to loosen a fastner meaning an impact with 640 ft-lb of breakaway would realistically loosen a fastner with an applied torque value of around 320 ft-lb.
There are a lot of variables for friction and such, but I think 1/2 the breakaway torque is probably a fairly decent ballpark estimate.
Issac Newton figured that out long before impact wrenches.
This is an Interesting read. ingersoll rand explanation of what the different torque values should mean. They explicitly mention that nutbursting torque is the torque on a bolt that your impact wrench can loosen if it has been torqued up by other means then an impact wrench ( they have the example of a manual torque wrench).
That would imply there is a difference between torque applied with an hammer mechanism or by rotational ‘power’ from a manual torque wrench