verifying torque value NEC 70B ?

[Joethemechanic]

I took apart an ac disconnect that someone at the same company installed a week before to see they had impacted the wire till it pinched the wire and it snaped under load.

Seeing that would me suspicious of anything that guy touched

 

[GeorgeB]

230618-0236 EDT

It is not "inch-pounds" that is a measure of work. The correct units are "pound-inches", like "newton-meters".

.

You are correct of course, but A*B=B*A so does it REALLY matter?

And which pound, pound-mass or pound force? Shall we slug it out? Indubitably, torque is a FORCE at a distance, so pound force here. Pound force USUALLY relies on gravity, so spring scales and load cell scales are force; what does a balance measure?

99% of this is playing games, remembering (very little of) my 55 year past high school physics.

 

[Joethemechanic]

"newton-meters".??????

With that kind of foreign talk, I'm about to break out my Whitworth Wrenches

 

[letgomywago]

Seeing that would me suspicious of anything that guy touched

He didn't last long

 

[rambojoe]

"newton-meters".??????

With that kind of foreign talk, I'm about to break out my Whitworth Wrenches

View attachment 2565889

Those "ahem".. would be spanners, mate.

 

[Sberry]

I took apart an ac disconnect that someone at the same company installed a week before to see they had impacted the wire till it pinched the wire and it snaped under load.

That falls under extreme stupid. It dont even count.

 

[gar]

280620-0022 EDT

If you use a balance scale, and you balance to null, then you have made a mass measurement. If you use a spring scale, then you do a measurement that is measuring force, and if go to different altitudes on the earth, then you will different readings of force on a constant mass.

Torque measurements are a very poor way to measure tension in a fastener, but from a production perspective it is about the only feasible method in most cases. Thus, one needs to tightly control all the various factors that affect torque. So for example the coatings on a nut used to hold a yoke or flange on a differential pinion have to be closely controlled. Back in older times pinion nuts were cadmium plated, and this material with an appropriate amount of wax produced a fairly good relationship of torque to pinion shank tension. Then the government banned the use of cadmium, and coating was changed to zinc. This provided a much poorer relation of torque to tension.

Many automotive axles are built with a collapsible pinion bearing spacer. These spacers have a rather good force vs displacement characteristic.So when one buils an axle with a collapsible spacer the spacer is really what reflects to pinion nut torque. Thus nut torque is not the controlling factor, rather the spacer is. The nut torque is still in the production spec. So one day we were getting a large number nut torque failures. The nuts were over waxed. So to solve the production problem we simple had an operator sand some of wax off. Another time we had nuts that were too far out of perpendicular. This day we simply looked at the nut as it was hand started, and discarded those that one could visually see wobble.

.

 

[jmellc]

hey guys I saw meant to say torque i apologize man im really making my self look dumb today

No worry, you're OK. We all make some crazy typos and get some crazy layovers from our systems.

 

[Wishiknew]

Hbiss is correct period.

 

[acin]

Sorry I had to be a wise ass

View attachment 2565867 View attachment 2565868

1/4 in. Drive 20-200 in. lb. Click Torque Wrench

Amazing deals on this 1/4In Dr Click Type Torque Wrench at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

just got that one. works great

 

[Fred B]

I took apart an ac disconnect that someone at the same company installed a week before to see they had impacted the wire till it pinched the wire and it snaped under load.

That falls under extreme stupid. It dont even count.

I've seen a lot of these that people will say "I just screw them down tight. Don't need no torque wrench."
Seen wire so pinched off so that when releasing the screw half the wire falls off. Even had service multistrand that had 5 of 7 strand fall off. Or so loose that the wire pulls out without ever loosening the screw.
Check behind one guy that "I have Been doing this stuff a lot of years and always just tighten and never had any issue. I just know." (calibrated elbow I guess). He had a panel full, and out of maybe 40 screws 2 were dead on, the rest were either too loose or too tight, some by a lot.
Checked with one of these type of calibrated things.

 

[Sberry]

I look over the names on this forum,,, 1/2 of them retired so this is a generation of YOUR kids we got to write an instruction manual and put a meter on a screwdriver for???? Who raised and trained these guys? Who showed them how to operate a screwdriver, ever check them,,, Billy, it needs to be a little tighter,,, no,, thats too tight it seized the screw. Looks like instead of doing that we been trying to invent a new tool?

 

[Joethemechanic]

With nuts and bolts you're in the range of large mechanical forces and you should understand that within these ranges metals are
elastic. When you take up a nut there’s a point called "finger-tight" where there’s contact but no takeup of elasticity. Then there’s
"snug," in which the easy surface elasticity is taken up. Then there's a range called "tight," in which all the elasticity is taken up. The
force required to reach these three points is different for each size of nut and bolt, and different for lubricated bolts and for locknuts.
The forces are different for steel and cast iron and brass and aluminum and plastics and ceramics. But a person with mechanic’s feel
knows when something’s tight and stops. A person without it goes right on past and strips the threads or breaks the assembly.



zen and the art of motorcycle maintenance, robert m. pirsig

Full text of "ZEN AND THE ART OF MOTORCYCLE REPAIR - ROBERT PIRSIG"

 

[letgomywago]

I look over the names on this forum,,, 1/2 of them retired so this is a generation of YOUR kids we got to write an instruction manual and put a meter on a screwdriver for???? Who raised and trained these guys? Who showed them how to operate a screwdriver, ever check them,,, Billy, it needs to be a little tighter,,, no,, thats too tight it seized the screw. Looks like instead of doing that we been trying to invent a new tool?

I take issue with some of the requirements but I understand that when equipment is made to an engineering spec so flimsy like now that they need this tool to hold your hand that's where we're at. It's also a Sue Happy society we live in

 

[Joethemechanic]

Very few kids learn any of the trades from a young age. They don't build stuff like minibikes and go-carts from the junk pile. They don't build electrical projects. As far as I can see they don't teach any theory in school. And guidance counselors, social workers and the like have treated education in the trades as a catch all for kids with behavior problems and any child with poor academic performance.

Unfortunately that is the caliper of workers we have to deal with. Any system you design has to be capable of performing reliably in the environment and with the materials you have. The workers are part of that environment. So basically you have to idiot proof the system.

Basically if we want to fix it we have to go back to this.


The St Francis Industrial School for Boys. Eddington Pa

 

[letgomywago]

Very few kids learn any of the trades from a young age. They don't build stuff like minibikes and go-carts from the junk pile. They don't build electrical projects. As far as I can see they don't teach any theory in school. And guidance counselors, social workers and the like have treated education in the trades as a catch all for kids with behavior problems and any child with poor academic performance.

Unfortunately that is the caliper of workers we have to deal with. Any system you design has to be capable of performing reliably in the environment and with the materials you have. The workers are part of that environment. So basically you have to idiot proof the system.

Basically if we want to fix it we have to go back to this.

View attachment 2566417
The St Francis Industrial School for Boys. Eddington Pa

I'm 26 and did all those things but it took my own initiative and kids now are handed a phone with games. Few people who grew up with me have developed a mechanical aptitude and those who did aren't interested in using it anymore.

 

[Joethemechanic]

The St Francis Industrial School for Boys. Eddington Pa

It was a pretty cool looking place. Shame they tore it down somewhere around 1990.

It was started by St Katherine Drexel's sister and funded by the Drexel Family. When I was a kid we used to go there all the time to play on the grounds. Lots of the boys who lived there went to school with us

 

[Sberry]

I had my son fix a grinder today. If he wants to can operate or drive about anything with a little coaching.

 

[letgomywago]

I had my son fix a grinder today. If he wants to can operate or drive about anything with a little coaching. View attachment 2566421

This should be added to the black and Decker thread

Nevermind you did

 

[PaulMmn]

Verify it using a torch wrench

Acetylene?