Ever wonder why you should invest in a torque wrench for scope mounting?

[Flopsweat]

I wonder if @Ura-Ki uses a torque wrench much at all. There's different kinds of master mechanics and I hear some hardly use them on a daily basis.

I know of a mechanic who uses his older impact wrench to torque most heavy bolts because he can go by feel. 80 lb/ft? That's two uga-dugas.

 

[Provincial]

Well at least being a Vortex, if it hit the ground and broke, they would send you a new one...or so about 1,000 salespeople have told me.

And yet another vote for the Fat Wrench...used mine yesterday. And as a gentle reminder for those who don't always read directions (um, that would be me), you should unscrew the tension all the way out between each use. True on most stuff like this.

I have a New Britain 1/2" drive clicker torque wrench that I bought in 1969. I sent it in for recalibration about five years later, and it passed. I've tested it against known good wrenches ever since then, and it still comes within one ft./lb. all through the range. I have been diligent in releasing tension on this wrench, and every other torque wrench I own.

I use a Snap-On 1/4" drive in./lb. clicker torque wrench on action, base, and mount screws. It is nearly as old as the New Britain, and also performs flawlessly.

 

[Ura-Ki]

I wonder if @Ura-Ki uses a torque wrench much at all. There's different kinds of master mechanics and I hear some hardly use them on a daily basis.

Naw, I use Ford Specs, tighten it till it screams, or G.M Specs, tighten till it breaks, or Mercedes Specs, GootenTight!
A lot of the engine work I do these days is Torque Angle, or Torque to Yield, so it doesn't really require a Torque Instrument.

Actually, unless it's called for, I don't really use a torque wrench all that much, usually my calibrated "Feel" is close enough!

 

[Provincial]

I wonder if @Ura-Ki uses a torque wrench much at all. There's different kinds of master mechanics and I hear some hardly use them on a daily basis.

I had a friend who was a lead mechanic for American Airlines. He rarely used a torque wrench. He had applied torque with his set of regular wrenches so much that he could tell by feel. I had him prove it one time, and he hit a 350 in./lb. torque plus of minus 10 in./lb. every time! Most were within 2 in./lb.!

 

[powermad]

I've seen enough $50,000+ engines that are complete scrap that I don't mess around.
Almost 10 years working on jets, no such thing as close enough.

One bolt backed out, $65,000 for that, engine only.

Bolt backed out for the idler gear and fell into the gear train making a spectacular mess.

Ordered it in March and just got it in and installed.

 

[MichaelH]

If you don't have a torque wrench the key is err on the side of under-tightening. For anything less than a barrel nut I'd go snug + a little more using my fingers on the tool (like arm not working at all) with no leverage. I'm always blown away at how soon my FAT Wrench breaks. If it comes loose see your friend with a torque wrench.

That's a bummer but it can be fixed. Sorry for your misfortune though.

 

[Yarome]

I'm always blown away at how soon my FAT Wrench breaks. If it comes loose see your friend with a torque wrench.

Yup. For a lot of firearm stuff it can take some getting used to and amazing how easy it is to over tighten shtuffs. When I first started using a wheeler I thought it was broke. "What?? That's it?? That CAN'T be tight enough!" ...But it was. 15-20in/lb dials up real quick and even 40in/lb takes a lot less effort than you might think.

What I used to think was "comfortably/snuggly tightened" was WAY over torqued.

 

[bionic knees]

snug them down good with a little blue Loctite, been working for me for several decades.

 

[kmk1012]

I've seen enough $50,000+ engines that are complete scrap that I don't mess around.
Almost 10 years working on jets, no such thing as close enough.

One bolt backed out, $65,000 for that, engine only.
View attachment 1279047
Bolt backed out for the idler gear and fell into the gear train making a spectacular mess.
View attachment 1279048
Ordered it in March and just got it in and installed.

The teeth on those gears look like they've been using meth for too long!

 

[Flopsweat]

Yup. For a lot of firearm stuff it can take some getting used to and amazing how easy it is to over tighten shtuffs. When I first started using a wheeler I thought it was broke. "What?? That's it?? That CAN'T be tight enough!" ...But it was. 15-20in/lb dials up real quick and even 40in/lb takes a lot less effort than you might think.

What I used to think was "comfortably/snuggly tightened" was WAY over torqued.

This was my exact reaction the first time I used the F.A.T. wrench. Then I went around to everything I owned with an allen nut/bolt on it and retorqued it.

snug them down good with a little blue Loctite, been working for me for several decades.

Funny when you only torque stuff to the recommended amount, suddenly you want that blue stuff on every fastener.

 

[Xmark1]

snug them down good with a little blue Loctite, been working for me for several decades.

Be careful with the blue Loctite. I have had to drill out one to many stripped hex bolt heads.

In fact, I currently have a handgun optic where the hex head stripped when I went to remove the Viper to change the battery. I am fortunate to have a drill press with a milling vice.

 

[Yarome]

Funny when you only torque stuff to the recommended amount, suddenly you want that blue stuff on every fastener.

Absolutely % Truth!

And you "cheat" just a little. If it says 15-18in/lb... I'm going 20in/lb. No way 15 can be enough. It's unnatural.

 

[Member 34319]

That's not a reason to buy a torque wrench, that's an example of why you buy better rings and scopes.

 

[thorborg]

I learned in my youth to appreciate the torque wrench. I had a small Honda I abused to the point I was always replacing piston, rings or timing chain nearly every month. No such thing as a feather touch for young bucks. Tighter was always better (leave it alone guys) and if it couldn't take the heat then something must be wrong with the metals. Wasn't long when every bolt and screw hole in that aluminum engine was filled with heli-coils and replacement screws. They weren't cheap back then and could have bought several wrenches for the money I spent. I Finally figured out in a back door sort of way that only a kid can do that a 1/4 inch craftsman socket wrench would strip before a 15 mm bolt would so being they were guaranteed I would use it as a torque wrench until Sears started having hissy fits on the many times I returned a broken wrench for replacement. Finally The guy said "look kid. why don't you get a torque wench and get professional". I did. Rarely broke or stripped another screw after that.
Back then, specs for torque levels weren't as easy to dig up as it is now in the computer age so today there is little excuse for my sort of idiocy. My next education came on learning how not to break a tap. Maybe more importantly, since breaking taps is inevitable sooner or later, how to remove them when I did.

 

[gsparesa]

*** Tinking Deeper ***

I ask this question in "light" of what has happened to the OP.

Question: Should we replace the scope mounting screws every time that we remount our scopes?

 

[Aero Denezol]

Looks to me like a better grade of bolts is what is needed.

That's why I quit buying Primary Arms. The early stuff was good, but lately the screws have been soft like play-doh. I torqued to spec using a fat wrench and boogered them up. Who has time to send stuff back under warranty. Better buy once and cry once.

I had a friend who was a lead mechanic for American Airlines. He rarely used a torque wrench. He had applied torque with his set of regular wrenches so much that he could tell by feel. I had him prove it one time, and he hit a 350 in./lb. torque plus of minus 10 in./lb. every time! Most were within 2 in./lb.!

I'm not surprised. Aircraft fasteners are as consistent and well made as possible, using only the best material. It is going to feel the same every time.

 

[Dr Prepper]

My vote if for fix it sticks.. Technically a tighter tolerances than fat wrenches or other adjustable Wrench's. Fat wrenched are good too just not as good.

 

[hongkong2]

That's why I quit buying Primary Arms. The early stuff was good, but lately the screws have been soft like play-doh. I torqued to spec using a fat wrench and boogered them up. Who has time to send stuff back under warranty. Better buy once and cry once.


I'm not surprised. Aircraft fasteners are as consistent and well made as possible, using only the best material. It is going to feel the same every time.

I've run into the same problem and now automatically replace all the enclosed screws with screws from Tacoma Screw.

 

[titsonritz]

A torque wrench doesn't make much difference when you dealing with Chinesium magnesium fasteners and with good hardware just use the German torque method...guntentite.

 

[baker3gun]

I put a torque wrench on anything that has a torque value.
Only takes a second and there's no second guessing if it's enough or evenly applied.

Between home and work I probably have 10 different torque wrenches.
Good from 5 inlb to 2,400 ft lbs with a 3/4"-1" 4x multiplier.

This reminds me of my personal dilemma.

After many years of turning wrenches on big and small stuff, I got to this weird point where specified torque often felt like not quite enough to me.
So I was always going just a hair tighter.

This led me to question whether qualified engineers were correct, or I was.
Naturally, I decided that all of them have always been wrong.

Nowadays, I still use a torque wrench on head bolts and hub nuts and the like, but otherwise not very often.

Clearly, YMMV.

Perhaps what it really comes down to is: how much is a hair?