Want to get yourself frustrated? Just try to teach someone proper screw tightness!

I do quite a bit of mechanical work in my everyday retired life. That obviously requires screws, nuts, bolts, etc to constantly be removed and replaced. Teaching people how to make a fastener tight enough to hold properly but not come loose is a difficult thing, I have discovered. I encounter innumerable quantities of stripped screws, stripped sheet metal threads etc that others have cranked so tight, they have strip. I have used the expression many times right here on this Forum to "make screws tight - but not Gorilla tight". I also read many posts that people state things just come loose on their own - so they were most likely not properly tightened to begin with. Locktite is not the general purpose answer, learning what tight enough is and what over tightening is would solve many issues with fasteners and would not require the use of Locktite. This does not apply just to guns either but with everyday items as well.

When it comes to critical assemblies, yes I do use one of my half dozen torque wrenches. For the most part proper torque used on everyday items is something that can be learned by most people, assuming they are interested in learning in the first place. No one walks around with a torque wrench and most probably don't even own one. If they do, they are a tool that rarely gets used except when critical torque is required. Learning how to make fasteners tight enough is sort of a skill that is hard to teach people because they do not have built in torque wrenches - lol. That said, I constantly try even though it is frustrating at times.

I believe that more mechanically inclined people should try and pass this technique along to Guys and Gals who frequently have issues with fasteners coming loose on their own or fasteners that have been stripped out. Seems like such an easy thing for mechanical people but can be very frustrating when dealing with others who have no clue. I've encountering many fastener related issues on guns and attached accessories loosening up on their own and screws so damned tight they need to me persuaded off. Today I worked on a neighbor's ac unit and I'd say half the sheet metal hex head screws had stripped out the holes they were in. I had to replace the screws with the next size to hold the unit's covers in place and the stripping had apparently been done by so called professionals - now that is sad!! A simple task that is not easy to convey. Ok - well that is my 5:00am rant. Have a great day - hope this helps at least a handful.

chief38 said:

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I'd say half the sheet metal hex head screws had stripped out the holes they were in. I had to replace the screws with the next size to hold the unit's covers in place and the stripping had apparently been done by so called professionals
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The use of battery screw guns instead of hand screws or wrenches causes much of this problem. I would bet that less than 5% of the “professionals” understand the use of the clutch on those tools.

Kevin

How did you learn proper screw tightness? I bet there was a learning curve where you made some newbie mistakes too. I know I sure did.

I wonder if the neighbors think I'm weird when I use a torque wrench out of the driveway when I'm rotating my tires? But that's one reason I do my own work. I don't trust taking my car into the "shops" because they hire people for minimum wage who don't know doodly-squat.

I bought an inch-pound, N-M torque wrench for working on bicycles, but it also comes in handy for other things.

StrawHat said:

The use of battery screw guns instead of hand screws or wrenches causes much of this problem. I would bet that less than 5% of the “professionals” understand the use of the clutch on those tools.

Kevin

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YES! I have seen the lion's share of "Pro's" using electric screwdrivers and battery powered drills to remove small little screws. The screws and threads don't have a chance! Use a powerful 14V or 18V Milwaukee or DeWalt on a #6 sheet metal screw and good luck with that! Hence the reason many are already stripped and other than cosmetics, do little to hold covers on. Certainly does not take much to strip a piece of sheet metal when they can not "feel" when the screw is tight enough. They could not care less!

I never use electric driven tools on any screw, nut or bolt until the diameter gets let's say about 1/4". When I do, I set the clutch to gently tighten and then finish tightening to final torque by hand.

clang444 said:

How did you learn proper screw tightness? I bet there was a learning curve where you made some newbie mistakes too. I know I sure did.

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You are absolutely spot on! When I was a teenager and started working on my own car I will admit to "Gorilla tightening" a few screws, nuts and bolts. After breaking some fasteners and cracking cast housings, it didn't take long for me to figure out how to do it properly.

That said, there are many adults who have never learned! Smart people learn from their mistakes, foolish people do not. They just continue to repeat them.

As stated, you need to take into account the size of the screw and also the material it is going into.

Thin sheet metal (like a downspout) strips really easily (don't ask me how I know this!) Then there's plastic, nylon, brass, ... all are really easy to strip the threads.

Then there's the question "How critical is it?"
If it's a lunar landing craft, somebody better be really careful about torque specs. If it's just putting the plastic panel back on after you change the battery in your calculator, "kinda snug" is plenty good enough.

Totally agree.. people don't know how to use clutch on electric tools. tighter is better...
I once had a guy ask to borrow my inch pound torque wrench to work on his timing belt job. I asked why he didnt own one? Told him if he did not own one, he probably did not know how to use it.
He did not like my answer. And, NO TOOLS Loaned!

There are a few people out there that have no mechanical ability. But most that cannot accomplish these tasks just never learned from lack of exposure to the process so I agree we should pass on our individual techniques. I know that is difficult to take in but we gun nuts, car nuts and clock nuts folks just take to it naturally while other very intelligent folks go "I don't know Jane, you think maybe another half turn? Well Bob I think more like 3/4 of a turn, that little slot will look better that way."

I do own and use a torque wrench for anything critical, especially for the initial assembly. This has given me quite a bit of training in what X amount of torque "feels like" at disassembly and that stays with me.

max503 said:

I wonder if the neighbors think I'm weird when I use a torque wrench out of the driveway when I'm rotating my tires? But that's one reason I do my own work. I don't trust taking my car into the "shops" because they hire people for minimum wage who don't know doodly-squat.

I bought an inch-pound, N-M torque wrench for working on bicycles, but it also comes in handy for other things.

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I always torque wheel nuts or bolts! It's extremely rare for professional mechanics or tire centers to do that. They just use an air powered (or electric today) impact gun and stop when the bolts no longer move much. When I fix a flat I do use a 1/2" drive Snap-On air gun but stop and finish with my 1/2" drive torque wrench. When I do fix a flat for a neighbor or friend, they usually ask me what the hell I am doing with that big long thingy......

But as screws, barrels, scopes, red dots, lights etc. pertain to guns, over tightening can become an expensive proposition and can lead to bunged up screw slots, scratched frames, hard to remove fasteners. Under tightening results in something coming loose, falling off and many just immediately go to Locktite.

I've done start-ups on new HVACR units. The install guys, I swear, stripped the screws out on purpose. They had no clue. I always had to carry boxes of #6, 8, and 10 screws. One punk asked me "How was the install? Everything okay?" with the stupid smirk on his face. I said "it looked nice; everything was good." That's how I really knew they stripped out all the screws on purpose. Not saying anything about really ticked them off.
Also, they were to dumb to figure out it was me that put Anti-Sieze on the under side of their truck door handles. Some of that aerosol grease on the driver side windshield wiper was a fun way to payback without their knowledge, too! My old co-worker friend & I will still talk about "Fun With Wire Ties!"

I hate working on anything that someone else has already worked on. If I was building engines, or something similarity critical, I get out my torque wrench. For what I do, my “Built in Torque Wrench” very rarely fails.

I won’t work on a car beyond oil changes and tire rotation. Motorcycles, for some odd reason, I don’t mind at all.

No machine thread that I reassemble goes back together dry.

The threads get a dab of low yield Loc Tite if it’s not coming back apart any time soon; like revolver side plate screws or scope mount screws.
On maintenance item like rotating tires I grease the male threads. I torque them to “Good and Snug”. Check them a day later, theyre always good, but check em anyway.

Tighten until the screw turns blue!

But seriously, Folks: Using a torque wrench is fine, but I just carefully tighten to "snug" with a properly-fitting screwdriver. I understand "snug" is vague but good judgement is required.

My usual approach is to tighten the fastener until I strip the threads, then back off a quarter turn.

16thVACav said:

My usual approach is to tighten the fastener until I strip the threads, then back off a quarter turn.

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That would be the racer's rule of thumb for torquing bolts. Used to do that too, at least until I discovered the secret torque wrench capabilities of all screw drivers and wrenches. The secret is in knowing just how many ugadugga's a fastener requires.

If it’s not stripping it ain’t tight enough

I had to send my Dewalt impact driver back, they forgot to put the clutch on it. The Wheeler screwdriver tips did fit right in, though.

In all seriousness, which I usually have to fake, an inch/lb torque wrench is a very useful tool when you want consistency. I used it when bedding and removing / replacing rifle stocks among other things.

Some people never get the feel, others don’t know enough to worry about it. We have the Bubba class that puts max plus on everything. These guys are hard on precision devices and valves. Other extreme just as bad.
The torque drivers just what they need.

For most applications, “tighten 1/6 to 1/3 past a significant increase in resistance” is a common aviation-maintenance standard in the absence of any other guidance is something that I use a lot.