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27 votes
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Why would I want to measure torque while loosening a bolt or nut?

Sometimes you want to measure breakaway torque. This can tell you if a fastener has started to loosen due to vibration, or was over-torqued and the bolt/stud may have stretched or weakened, or the ...
TMN's user avatar
  • 2,311
22 votes
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Why tighten down in a criss-cross pattern?

There is more to it than just a "criss-cross" pattern. You should also work your way out from the middle in stages of bolt torque. If you imagine tightening a cylinder head down starting at the two ...
HandyHowie's user avatar
  • 25.4k
18 votes

Torque wrench or impact gun on large bolts

To answer your question directly, this is a "standard practice" but a VERY poor one. Getting the correct torque is by far more important than getting it done quickly. With the axle nut it is ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
16 votes
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Is each turn with a beam torque wrench additive?

If that would be possible, every 3-year old could fasten the bolt. He just has to try 100 times with 0.5lb-ft. You have to apply the full 50lb-ft, regardless of the torque applied before!
sweber's user avatar
  • 7,057
15 votes
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Does using a ratchet size adaptor on a click-type ratchet wrench reduce the applied torque?

No, it won't reduce the torque. Torque is equivalent to radius x force. As long as A, the force is applied at the same distance from the nut/bolt that you're tightening and B, it's applied in the same ...
Craig Lafferty's user avatar
13 votes
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What fasteners should not be loosened using an impact wrench, and why?

As the name suggests, impact wrenches have the ability to impart high amounts of momentum change. The delivery of this momentum change is hard to meter, so it is quite easy to damage: soft metals ...
Zaid's user avatar
  • 39.2k
13 votes

Why tighten down in a criss-cross pattern?

In general things should be tightened in stages with some sort of crossed pattern depending on the number of fasteners in the circle. Not doing so creates a bias that could result in false torque ...
SteveRacer's user avatar
  • 12.4k
12 votes
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Torque wrench or impact gun on large bolts

Neither. Just get a 1m long bar (by extending a breaker or similar), stick it on the nut so that it is horizontal and simply hang 250N of mass at the end of it: (*) 250N = 56.2 lbs = 25.5 Kg 250N * ...
Lamar Latrell's user avatar
12 votes

I stored my click torque wrench in a mid-high setting. Is it ruined?

If you have one of these, you could easily test it yourself. I admit: this is not the most accurate way to measure the callibration, but it's probably the easiest way to give you a rough idea. (Image ...
user60481's user avatar
  • 1,339
10 votes
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Horsepower at wheels calculation

TL;DR The problem you are encountering is the limited resolution of your speed plus fluctuation plus slightly different approaches to calculate power. And finally, you have to think about the term ...
sweber's user avatar
  • 7,057
10 votes
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Impact sockets with a Torque wrench reduce accuracy?

Short answer : no, you can't apply the force suddenly enough to make the socket flex to make a difference - what can skew the readings or, at least, the torque applied is friction between the nut or ...
Solar Mike's user avatar
  • 34.6k
10 votes
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Can I use a 15lbs torque wrench for 13lbs spark plug job

While it most likely will be OK, it is not worth the risk. If you do over torque the spark plugs and strip the threads you will regret it because it will be a big job to get it fixed. Most mechanics ...
HandyHowie's user avatar
  • 25.4k
10 votes

Can I use a 15lbs torque wrench for 13lbs spark plug job

The lower and upper ranges of the torque wrenches are generally unreliable. With a bit of bad luck the deviation of the torque wrench is too large for the threads. I'd consider getting a smaller ...
Martin's user avatar
  • 8,458
9 votes
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"Always Replace" (torque-to-yield) Bolts

I cannot tell you directly if the bolts you are using are Torque to Yield (TTY or T2Y) bolts, but if Bently says to replace them, you bet I'd do it. What are three bolts in comparison to the well ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
9 votes

Are there "standard" torque values for fasteners?

tl dr: No. There are too many variables. There are two things at play when tightening a fastener for an oil pan: How much torque can the fastener actually handle? How much squish can the gasket ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
9 votes
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Why do service manuals specify a range for torque? Are there any reasons for being at one end or the other?

No, I think it has more to do with an expected range, given the vast number of torque tools, operator technique, and the distinct lack of calibration of most folks' torque wrenches. (And I am as or ...
SteveRacer's user avatar
  • 12.4k
9 votes
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How many times can you go through a torque sequence when installing heads? I'm worried I messed up and should try again but don't wanna make it worse

Considering you have torque to yield (T2Y) bolts, once torqued through the angle sequence, you're done. If you remove the bolts, you have to start over with new bolts. T2Y bolts are one and done, ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
8 votes
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What is the maximum torque a 1/2 drive can withstand?

Good question, while we probably can't just ring up a tool manufacturer and ask, we can derive it with some accuracy: Maximum socket size I can find for 1/2" is 36mm, that translates to an M24 fixing:...
KnowledgeQuest's user avatar
8 votes

Why tighten down in a criss-cross pattern?

Cross fastener tightening accomplishes: It keeps the components being fastened aligned, and not cross mounted. This is a particular risk when a component is interior to a flange. It helps keep the ...
mongo's user avatar
  • 2,115
7 votes

How to lock crank shaft while torquing central screw?

There are a few different ways I can think of to do this: If the vehicle has a manual shift transmission, put the transmission into the highest gear, then set the parking brake. The torque provided ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
7 votes

Uses of small sized 1/2" drive sockets

If you have to start somewhere and need a complete set to do your job, having the 1/2" drive go down to the 8mm size helps you to do this without having to buy the smaller set. If you can get the ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
7 votes
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Are there "standard" torque values for fasteners?

The answer is no. Absolutely not. Those charts are not for automotive kinds of torque. Every "chart" or "table" about specific grades of fasteners are for achieving a condition called critical ...
SteveRacer's user avatar
  • 12.4k
6 votes

What is the maximum torque a 1/2 drive can withstand?

I can't answer for 1/2" but I just bought a 1/2" to 3/8" coupler from Facom and stamped on the side it says "maxi 202 Nm", which equates to about 150 ft lbs. I think 150 ft lbs is about the most a 3/...
Ron Weasley's user avatar
6 votes
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Given the following scenario, what type of engine (diesel or petrol) allows for greater acceleration and/or top speed?

Torque doesn't matter. It's power. The difference is that diesel engines have their peak power at lower RPM compared to petrol engines. Same power at lower RPM means more torque. (Think about: The ...
sweber's user avatar
  • 7,057
6 votes
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Where can I get my torque wrench calibrated?

Any MAC or Snap-On truck/dealer has a universal calibration tool that will check the calibration. The issue is that if they are "off", they will probably not have parts if needed, or perhaps the ...
SteveRacer's user avatar
  • 12.4k
6 votes

Why would I want to measure torque while loosening a bolt or nut?

If you fear that the nut or bolt are seized, and you don't want to damage the part it's attached to with excessive force, you would use a torque wrench to warn you that you are exceeding the torque ...
Adam Davis's user avatar
  • 1,587
6 votes
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Torque specification thread lubricant best-practice as specified by manufacturers

In general, the assumption is that you are not using a lubricant. When a lubricant is specified, obviously then you use it. Using a lubricant will result in the same torque readings, but higher ...
dlu's user avatar
  • 14.5k
6 votes

How can a model with a smaller engine produce more power?

I am guessing that the smaller engine has a turbocharger and the larger engine doesn’t. This would fit with the smaller engine having a lower compression ratio. The turbo compresses the air entering ...
HandyHowie's user avatar
  • 25.4k
5 votes

Uses of small sized 1/2" drive sockets

Convenience, mainly! Lots of small parts such as covers are held on with small bolts, and it means you can cover the full range of useful sizes with just one set, should you so wish.
Nick C's user avatar
  • 28.8k
5 votes

How to lock crank shaft while torquing central screw?

An old trick for this is to remove a spark plug, then feed a length of string into the cylinder through the spark plug hole, leaving enough string hanging out to pull it all out when done. The string ...
CBRF23's user avatar
  • 536

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