Drive size vs Nut and Bolt size

[jeejay]

I was testing out different sized drive handles on a 3/8" coarse thread nut and bolt, with 9/16" hex head, and 6-point or crowfoot sockets. The bolt is going through a piece of steel plate clamped in a vise, and fits closely through the hole drilled in it, so there's no wobble to it.

Looks like the weight of a tool affects thread wear most, and the nut wears down fairly fast when tightening and loosening it repetetively, regardless of its grade, or mixture of grades. By comparison, finger tightening and loosening the hardware won't wear it down, so obviously the heavier the handle, the more threads will grind together in the process, and some of that would have to do with how evenly it is held when being turned.

Apparently 1/4" drive tools in general would be best for this fastener size, for their lighter weight, even though 3/8" and 1/2" drive tools have these size sockets too. Just an observation on my part, has anyone else compared notes on this?

 

[LXCam]

With all this time on your hands I'd have to imagine you would have come to realize that weight has nothing to do with it as much as off center leverage does and how it's imparted on the center line of the fastener, per your analogy

 

[cvairwerks]

Wear on threads is also highly dependent on fit classification. Class 1 fits are pretty loose and require minimal running torque, where as a Class 3 is much tighter and the running torque can come into play.

 

[toolaholic]

Just for shits and giggles I thought I would tighten the lower strut bolts(around 125foot pounds) with my 17 inch long Sk ratcheting 17x19mm wrench and the other side with my 18 inch long 1/2 drive Armstrong 12-994 ratchet. Both were fine. Sometimes I like to play around and compare wrench to ratchet etc. The Yaris didn't care , it likes it new struts. Your wear and tear on threads based on drive size is interesting.

 

[larry_g]

I would need a detailed description of your testing procedure and just how and where you are measuring this 'wear'. How many repetitions of the of the test before you measure the wear? Details man, details. Otherwise.....

lg
no neat sig line

 

[AngryBeaver]

fastener engagement also contributes....

a chinesium socket will "wear" out the hex faster than a quality made to fit socket.....

open end wrenches will always provide more "wear" than a socket or box end as the contact points are 3x less.

 

[jeejay]

I wasn't testing the hardware in particular, just configuring some handles, and thread wear was a side effect of some. A smaller fine thread nut and bolt lasted much longer, all else being equal, so I think thread type is another factor (or how close together they are, because there's more movement in the bolt hole between threads that are spaced apart, regardless of how closely the bolt fits through it). For practical purposes, weight has to do with it as much as it may be impractical to hold a handle perfectly balanced in one hand while turning it, while any amount of weight on the bolt will tilt it somewhat (or that would become more pronounced as drive size increased).

 

[jeejay]

Then again, I may be jumping to conclusions there, because a nut will match the tilt of a bolt as it threads on, so that shouldn't matter as much. The bolt is not wearing down throughout its length, but at the point where the nut is torqued tight, so I think this is mostly to do with clamping and unclamping the sharp points of metal threads repeatedly. I was looking at it from the perspective of the nut wearing down sooner than the bolt, as far as considering the rest—or it only seemed to, because it didn't match the unworn bolt threads farther out, after a while.

Are some nuts and bolts better for torqueing on repeatedly, as far as not wearing down because of that? I was reading that leadscrew threads are better for heavier loads, but those aren't typically used as fasteners. Maybe they're only made to clamp down a few to several times otherwise. Or plastic ones would be better for testing things out (if they could handle the weight). I'd tried adding gear oil to a metal fastener, but snapped it with a short 1/4" drive handle before it clamped tightly, and it isn't that I'm over torqueing on them to cause excessive wear, just retightening them more often than typical use. It doesn't take much more than that sometimes to render them useless. I'll have to try a fine threaded bolt the same size also, I was surprised at how fast a grade 8 coarse thread wore out.

 

[jeejay]

Alright, well I got a nylon nut and bolt, and don't hear any grinding (yeah, there was metal dust on my vise from the others). Drive size actually comes into play there, because nylon is slippery, whereas a socket would hold most of them on the steel by itself. It has to do with the depth of the socket also, a 3/8" crowfoot with a 7" handle will balance itself on the cap screw head, but a standard depth 3/8" socket on a 5" handle slips off, even though that one is lighter weight. I think the slipperiness is what helps threads stay intact on those. Nylon is one of the most widely used plastics in the world. All grades maintain great strength and offer extremely good wear resistance. I don't know about "great strength", but will see about wear resistance.

Well, realistically I think nylon is too smooth for comparing different hand tools. I'm only getting a couple turns of a wrench before it's tight, compared to eight or so with fine threaded steel. That seems to wear down slower than coarse threads had in the same bolt size, so I guess it's the best option around here. Nylon might be better for some wing nuts though.

 

[jeejay]

Later I thought to try wrapping teflon tape around the worn threads, and it smoothed them out again, like new. So that's the great equalizer for this situation, where I still get as many turns out of them with it on there (in other words, it didn't make it like having oil on them or nylon threads either).

Anyway, thanks for the advise too.

 

[Fedwrench]

Much to do about nothing.....

Aside from lug nuts, wheel studs, and the oil drain plug, what fasteners on a regular car get removed and reinstalled repeatedly.

Since you have so much time on your hands compare fastener wear from using hand tools versus power tools.

Have a nice day

 

[davethorik]

Much to do about nothing.....

Aside from lug nuts, wheel studs, and the oil drain plug, what fasteners on a regular car get removed and reinstalled repeatedly.

Since you have so much time on your hands compare fastener wear from using hand tools versus power tools.

Have a nice day

You mean actually add tech to the site, and not just dredge up old threads and make pointless new threads where he talks to himself about things that don't matter? Blasphemy

 

[bob15]

Help. What is the objective of this thread? I'm confused

 

[FMC1959]

Kinda reminds you of...
https://www.google.ca/search?q=sein....69i57j0l5.25626j0j7&sourceid=chrome&ie=UTF-8

 

[LXCam]

Help. What is the objective of this thread? I'm confused

The objective is how much alcohol can be consumed over the course of a three day weekend before you can no longer type legible.

 

[American Locomotive]

I'm still trying to figure out how exactly you're measuring thread wear? There are bolts in some pieces of equipment I have that I must have run in/out hundreds of times with no appreciable wear.

 

[larry_g]

Aside from lug nuts, wheel studs, and the oil drain plug, what fasteners on a regular car get removed and reinstalled repeatedly.

Have a nice day

Why do most seem to assume that everyone on this site only works on cars? Lots of fasteners on machines get installed and removed repeatedly. I've replace many worn out fasteners on machines.

On the other side I too have no idea what the OP is on about.

lg
no neat sig line

 

[Wakefield]

Why does an engineer choose fine thread vs. course thread fasteners?

 

[Fedwrench]

Why do most seem to assume that everyone on this site only works on cars? Lots of fasteners on machines get installed and removed repeatedly. I've replace many worn out fasteners on machines.

On the other side I too have no idea what the OP is on about.

lg
no neat sig line

Because it's The Garage Journal and there are even pictures of an old service station with cars in the heading.

 

[M6erfan]

Whaaaaat???

 

[jeejay]

Anyway, thanks for the advise too.

Okay I was talking to myself then (whatever works).

 

[Olafur]

Looks like you are onto something. When you figure it out - keep us posted.

 

[BDT/NWMN]

The bad news is that flies can land on those bolts and take a dump; which will either gum up or corrode the threads. But on the other hand, the fly dump may act as a lube.

The good news is those flies cannot be in two places at once; so My fruit basket will be less polluted.

 

[JimRB]

You did not specify what grade bolt and nut you were using, if you deburred the hole, if the hole was 3/8", if you were using an accurate torque wrench to torque to the bolt's specification (each grade bolt has a different torque value, dry or oiled torque value is different, bolt plating also affects torque values), if you were using quality unworn socket and crows feet that fitted properly, how many times you tightened and loosened the nut.

An article on fastener failure. http://www.croberts.com/bolt.htm

 

[Spacey_G]

Why does an engineer choose fine thread vs. course thread fasteners?

For the larger tensile stress area? More thread engagement in thin walls? Less likely to loosen from vibrations?

Not sure what you're going for.

 

[jeejay]

Well, it wasn't actually a hypothetical question, because I've also found that there are PTFE coated fasteners, which they say it maximizes their life, because of reduced friction and corrosion, allows for easier removal of frozen nuts, and reduces torque requirements. I'll just stick with rewrapping the PTFE tape on any one bolt as needed, instead of buying boxes of hardware.

 

[American Locomotive]

You still haven't explained how you were measuring thread wear.

 

[Olafur]

What equipment are you dealing with where thread wear is an issue?

 

[jeejay]

I'm not talking about thread wear as in redundant posts here, already solved that simple to understand problem to do with metal threads, so yeah.

 

[Gmonkee]

Ok, what brand of absurd is this about and how does it apply to anything real?

 

[jeejay]

 

[leg17]

Far out man

 

[American Locomotive]

I'm not talking about thread wear as in redundant posts here, already solved that simple to understand problem to do with metal threads, so yeah.

Explain how you measured the thread wear.

 

[jeejay]

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[jeejay]

Make sense? I did explain enough to begin with, and apparently it didn't do any good. The other explanation was deleted (« Next Thread | Previous Thread »), as if it were too controversial. Actually that explained both contexts (so I've put it back for now). It's a moot point anyway. If I were talking about tread wear on tires, and said I'd retreaded a bald tire, then someone, or everyone asked for an explanation of measuring tread wear, um... it was bald. What else would you be going for but a rhetorical response by asking? Go ahead and play games, if that's the case, but like I said, the problem was already solved, so comprehending that should not be a problem (or I don't have a problem if you don't want to). If you feel like explaining how you'd measure thread wear, as it were, be my guest.

Or if anyone wants to spin this into an argument about tires, have fun with that too (but how many revolutions of the balding tire did you... uh, and for what odd reason have you encountered this tire, for its wear to cross your mind)...

Gotta love information highways, excellent drivers, yeah, excellent drivers. ​