Applying Torque In Tight Quarters, Can Torque Be Additive?

[winlinmac]

Suppose I had to apply torque to a bolt or nut which required 75 ft lbs of torque and the area surrounding it was cramped (unfavorable conditions), would applying a torque three times (25 ft lbs each) allow me to reach the total or close to 75 ft lbs of torque required for that particular fastener?

 

[txvwnut]

Re: Applying Torque In Tight Quarters, Is This Method Favored?

No.

The torque wrench will click at 25lbs everytime and not move the fastener past that.

 

[pistolpete1313]

Re: Applying Torque In Tight Quarters, Is This Method Favored?

If I understand the question right, no. It is not additive.

 

[jumbojak]

Re: Applying Torque In Tight Quarters, Is This Method Favored?

No. Torque is the product of force and distance. Addition doesn't come into play. As a thought experiment, imagine that you applied a specified torque under favorable conditions - like a bolt and arbor mounted in a vise. The same torque was applied each time and the bolt doesn't wind up any tighter than the first.

 

[winlinmac]

Re: Applying Torque In Tight Quarters, Is This Method Favored?

Thanks for the clarification. I visit several automotive forums from time to time and come across some DIY'ers using this flawed method; Its not even a method

At least I'm not misunderstanding here.

Therefore, in tight quarters, is the only solution to use a smaller sized / drive torque wrench?

It almost comes to the same debate as to when some use extensions, crowfoots, and drive conversion adapters on their torque wrenches.

 

[Wakefield]

If you have a Universal or Impact Swivel in line with the torque wrench and extensions at an angle I think you might not get full torque to the working end and it might depend on exactly how the universal joint is turned-like taking the socket off the spark plug and rotating 1/6 of a turn or 1/3 of a turn might change the torque that gets to it

 

[pistolpete1313]

Re: Applying Torque In Tight Quarters, Is This Method Favored?

They have open ended torque wrenches for situations like that. Not cheap, I don't own one but probably the preferred tool for the job

 

[LXCam]

 

[jumbojak]

Barring a wrench that's short enough to meet space requirements you really have two options that I know of. The first is to just guess. I know that many people frown on this method but in a lot of cases it get's the job done. There's a video somewhere on YouTube where a guy loudly says "click" while doubling up on wrenches to tighten lower control arm bolts! The second option is to apply a calibrated load to a lever of a known length... easier said than done. ESPECIALLY if the bolt has to be tightened horizontally and you don't have the benefit of gravity.

 

[Ole Slewfoot]

You can also build or buy a torque adapter like this

 

[Burgerkong]

I've done the hex socket with a combo or ratcheting wrench, as long as you know the exact distance from the center of the socket to the center of the open end on the wrench you can calculate how much torque you need to apply via a simple moment calculation.

EDIT: Link added for clarification http://www.engineersedge.com/manufacturing_spec/torque_wrench_1.htm

 

[firworks]

Can you link us to one of these other automotive forums so I can actually see a post with someone else asking this question? I kinda don't believe it.

 

[Provincial]

In a similar situation in the past, I have set up a "dummy" fastener and applied torque by hand using the same tools/angles as the "real" setup. Make sure your body/arms/hands are in the same position as the real application so you are applying the same pull you would there. I guess at the torque applied and check it with a torque wrench. Back off and repeat until you are hitting the right torque. I have a good feel for torque applied, so it doesn't take long to "dial it in" Once you have the feel, move to the actual piece and apply the same amount of force.

Most applications have a minimum and maximum torque reading, which allows you some latitude.

 

[T45]

the purpose is to get the right bolt stretch on the fastener, don't forget. the torque is just a guesstimate for the clamping force load. Ultimately the bolt needs to be stretched so you need to put the correct force onto it with a tool. The space being crampd simply requires a shorter tool or a workaround like a torque adapter. The main issue you will likely face is that 100nm typically requires a decently long torque instrument, like mayve 12 but usually more likelt 14-18 inches long range.

 

[no704]

Many appiliacons need a 2 grunt torque ( compressing a gaskit) but must be tightend in sequence. Some need 3 grunts( flywheels etc. ) some only need one grunt(spark plugs).

 

[Superbec]

Can you link us to one of these other automotive forums so I can actually see a post with someone else asking this question? I kinda don't believe it.

it's additive as when you count your money and every time you re count it adds up.

 

[FigureItOut]

Many appiliacons need a 2 grunt torque ( compressing a gaskit) but must be tightend in sequence. Some need 3 grunts( flywheels etc. ) some only need one grunt(spark plugs).

So in a two grunt application, when torqueing in sequence, do you do one grunt around in your pattern, then repeat the pattern with a second grunt, or must you tighten each bolt to a two grunt spec the second time around?

Sent from my XT1575 using Tapatalk

 

[eyeball]

Can you link us to one of these other automotive forums so I can actually see a post with someone else asking this question? I kinda don't believe it.

Unless it was posted on April Fools day, it might not exist.

Sent from my GT-P5113 using Tapatalk

 

[nh_yota]

Suppose I had to apply torque to a bolt or nut which required 75 ft lbs of torque and the area surrounding it was cramped (unfavorable conditions), would applying a torque three times (25 ft lbs each) allow me to reach the total or close to 75 ft lbs of torque required for that particular fastener?

If you can get it to 25 ft/lbs why can't you get it to 75 ft/lbs? Most torque wrenches have a ratcheting head so you just tighten it a bit, pull the handle back and then tighten it some more.

 

[nh_yota]

If you have space constraints you can also use a crowfoot wrench and an extension, but you need to calculate how much to reduce the torque setting on the wrench to account for the additional offset.

 

[OutsideMachinist]

If you have space constraints you can also use a crowfoot wrench and an extension, but you need to calculate how much to reduce the torque setting on the wrench to account for the additional offset.

So yeah theres a lot of ways to deal with this as previously mentioned in the thread. This also will work. If you can get the crowsfoot or torque adapter at 90 degrees to the torque wrench then you dont have to adjust the torque calculation. If it extends forward, increases the length and leverage of the torque wrench then you would apply less torque. Opposite if it had to extend downward and decreased the length of the torque wrench.

Not sure exactly what you are torqueing but you could also try torque by flats, which isnt the most accurate but better than nothing. If you have another fastener that will be torqued to the same amount you mark it and count the flats moved to achieve the final torque, then apply that to the fastener in question.

 

[no704]

So in a two grunt application, when torqueing in sequence, do you do one grunt around in your pattern, then repeat the pattern with a second grunt, or must you tighten each bolt to a two grunt spec the second time around?

Sent from my XT1575 using Tapatalk

Absolutely first start with one grunt in the pattern, then proceed to two grunts.

 

[DenisG]

If you were able to put 3 torque wrenches lined up on the same axis and set them to 25 ft-lbs individually, you would get 75 ft-lbs IF you turned them all at the same time. But that would require 3 hands and torque wrenches that could work all lined up on the same axis.
When you think of an engine crankshaft, that's an example where torque is additive with the total torque summed up from the contribution of each (firing) piston along the crankshaft.

 

[ruffryder]

If you were able to put 3 torque wrenches lined up on the same axis and set them to 25 ft-lbs individually, you would get 75 ft-lbs IF you turned them all at the same time. But that would require 3 hands and torque wrenches that could work all lined up on the same axis.
When you think of an engine crankshaft, that's an example where torque is additive with the total torque summed up from the contribution of each (firing) piston along the crankshaft.

umm.... that doesn't work with a torque wrench. If you tighten a bolt to 25 ft lbs with a torque wrench, take the torque wrench off, then put it back on and tighten it again, you do not get another 25 ft lbs. Using three torque wrenches at the same time, all set to 25 ft-lbs will result in all of them stopping or clicking out at 25 ft - lbs. There is no addition here. It isn't each torque wrenches increase in torque on the bolt, but the total torque on the bolt as seen from the torque wrench.

As to you engine comparison, the torque due to difference cylinders isn't completely additive, for instance, the total torque of the engine is not the total torque from one cylinder multiplied by the number of cylinders on the engine. (caveat, unless it is a 1 cylinder engine, or all cylinders are in phase with each other, which I don't think has ever been done).

Note that engines have a firing order, therefore they are not all firing at the same time. When one cylinder is done providing torque due to the combustion phase, then another one will provide torque due to its combustion phase. The overlap between cylinders phasing would be additive though.

I hope that makes some sense.

 

[notlob]

Put a 3 foot lever arm on the torque wrench (total length from center of bolt head to location force is applied), apply 25 lb force at the end of and perpendicular to the lever arm, then you'll have 75 ftlb of torque.

3 feet * 25 lb = 75 ftlb

 

[Superbec]

If you were able to put 3 torque wrenches lined up on the same axis and set them to 25 ft-lbs individually, you would get 75 ft-lbs IF you turned them all at the same time. But that would require 3 hands and torque wrenches that could work all lined up on the same axis.
When you think of an engine crankshaft, that's an example where torque is additive with the total torque summed up from the contribution of each (firing) piston along the crankshaft.

can you please apply this logic to the money in my wallet?

 

[dlwilson]

You can also build or buy a torque adapter like this

Is that what that is? I've had one kicking around from bench to box for years. I bought it at a BMW mechanic's estate sale. I thought it was some kind of distributor wrench, or maybe something for airplane engine cylinders.

 

[ruffryder]

Put a 3 foot lever arm on the torque wrench (total length from center of bolt head to location force is applied), apply 25 lb force at the end of and perpendicular to the lever arm, then you'll have 75 ftlb of torque.

3 feet * 25 lb = 75 ftlb

If he doesn't have space for a larger torque wrench, why would he have space for a 3 feet lever arm?

 

[FigureItOut]

OP, I'd be willing to bet that if you post a pic of your situation, a member will see a solution that you're not seeing. Sometimes all it takes is a second set of eyes.

Sent from my XT1575 using Tapatalk

 

[lazer50]

I already posted about the op question and agree if he had a picture. But i have a curious one myself does anyone here get there torque wrench or wrenches calibrated when purchased or periodically?