Torqueing screws for cheapskates

I've finally got around to getting my first scope mounts and am in the process of mounting them. I've read a lot about the importance of correct torque on the screws. The thing is, I'm too cheap to buy a torque driver I'll use a handful of times and hate borrowing tools so I've had to contrive a way to get the correct torque with a high degree of accuracy once I've leveled the optics etc. I thought I'd share it for fellow cheapskates.

Based on the engineering toolbox idea of using a luggage scale on a crescent spanner, I'm using the allen key supplied with my mounts with a exercise weight attached by fishing line near the end. Since T=Fa, where a= the length of the lever, with a given weight I can vary the torque by shifting the point along the Allen key it's attached (it's 60mm long). A quick cut with a file so the fishing line doesn't slip off, and I can get the torque within about 1 in-lb. This will work equally as well as the luggage scale method.

I've made a spread sheet to make the calculations easy. In my case, I need to torque the ring screws to 2Nm / 18in-lb. So I enter in 2 in the torque cell, 5kg in the weight cell and it gives me 41mm (0.041m) for my attachment point.

Link

Of course I could pay $10 to get a luggage scale delivered but I already have the fishing line and the weight. With the savings from not buying a wrench I can buy a box of ammo!

Borrow one.

In order of importance:
1. Last tool I lent went 'missing'.
2. Last time I borrowed a tool it broke.
3. I don't know anyone with one.
4. This way is much more fun.

Always identify your target beyond all doubt because you never miss and I will be missed

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Originally Posted by MB

Borrow one.

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Just buy one.....they are not that expensive. You will use it more than you think and just so quick and convenient.
I bought a vortex one from trademe been bloody brilliant.
You can even spread the payments using afterpay if the initial outlay is prohibitive.

https://www.trademe.co.nz/a/marketpl...ing/3800345795

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Originally Posted by muzza

I think you are over complicating the whole procedure.

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Don't forget to calculate in the prevailing torque and watch the angle of pull, as well as any wet install torque. :yaeh am not durnk:

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Originally Posted by dannyb

Just buy one.....they are not that expensive. You will use it more than you think and just so quick and convenient.
I bought a vortex one from trademe been bloody brilliant.
You can even spread the payments using afterpay if the initial outlay is prohibitive.

https://www.trademe.co.nz/a/marketpl...ing/3800345795

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I think our definitions of inexpensive are different
https://www.trademe.co.nz/a/marketpl...5?bof=ZwMcZ1XO

This version is free...

If you haven’t already fitted your scope you’re welcome to borrow mine. I’m close enough to Carterton that it won’t be inconvenient for anyone.

If you end up having to re torque your scope after your first trip to the range, that extra box of ammo will be handy for re sighting in. :thumbsup::thumbsup:

I have done mine up firm by hand for ever...and will continue to do so....

I have done the same (by feel) for ever but since moving to a system where I swap scopes I want to be precise when I change them.
I recently mounted a scope with the rifle in a vice and the scope aimed into the distant farmland. It was interesting watching the cross hairs move as I tightened the screws. I don't think the actual torque figure is as important as the consistency of the setting.

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Originally Posted by Micky Duck

I have done mine up firm by hand for ever...and will continue to do so....

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I use a torque wrench because I have one from a previous career. Before the torque wrench I used to just crank them up to ‘just before they went loose again’. Never came unstuck with steel on steel but have had the odd whoopsie with aluminium.

https://www.sheldonbrown.com/tork-grip.html

Just to be clear this is not a dig at the method outlined by the OP, I post because anyone reading this thread will appreciate it.

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Originally Posted by longshot

https://www.sheldonbrown.com/tork-grip.html

Just to be clear this is not a dig at the method outlined by the OP, I post because anyone reading this thread will appreciate it.

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Did you find this through an internet search engine or a you an aficionado of bicycle esoterica?!?

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Originally Posted by Steelisreal

Did you find this through an internet search engine or a you an aficionado of bicycle esoterica?!?

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Years ago when ordering online was still fairly novel, I looked at buying a torque wrench online, found that website, just quietly I didn’t realise it was a piss take at first, gave up reading about 1/4 of the way through thinking the thing wouldn’t be much use. Also gave up on buying online for a while after that too.

Complete waste of time! Just nip them up firmly with a drop of LocTite on the threads (bases only). After fitting literally thousands of scopes over the past 60 years I believe torquing scope screws has about as much validity as getting 72 virgins after blowing yourself up!

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Originally Posted by Shearer

I have done the same (by feel) for ever but since moving to a system where I swap scopes I want to be precise when I change them.
I recently mounted a scope with the rifle in a vice and the scope aimed into the distant farmland. It was interesting watching the cross hairs move as I tightened the screws. I don't think the actual torque figure is as important as the consistency of the setting.

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I've done a bunch of scope switching and have never found the torque to make a difference (ring to pic rail screws obviously), using a variety of different types and brands of rings/mount the only ones I've found that were sensitive to torque/installing were Burris XTR rings (due to their different construction).

I never use a torque wrench for scope rings, have installed dozens of scopes and rings of a variety of brands.
I personally think more damage is done to scopes from people using a torque wrench wrong than being over tightened by hand.

It’s about consistency that’s all , done some reading over the years on the subject , most will say you need a drop of oil on a thread to torque it / tighten it , you are trying to put tension on the thread without the thread actually binding together .

I don’t get why many shooters seek out and invest in gear machined to really fine tolerances and then ignore manufactures torque recommendations.
Decided to up my game when I bought a couple really nice rifles and scopes, but I do come from an industry though where mechanically, she’ll be right doesn’t cut it.
I guess it depends on individual investment and their expectations as much as anything.
At the range I’ve witnessed satisfaction at some astonishingly poor shooting, so understand the concept of correctly torquing fasteners is completely lost on more than a few.

Given I'll be torquing steel screws (I think) into aluminium rings I agree entirely.

Sent from my SM-A520F using Tapatalk

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Originally Posted by Moutere

I don’t get why many shooters seek out and invest in gear machined to really fine tolerances and then ignore manufactures torque recommendations.
Decided to up my game when I bought a couple really nice rifles and scopes, but I do come from an industry though where mechanically, she’ll be right doesn’t cut it.
I guess it depends on individual investment and their expectations as much as anything.
At the range I’ve witnessed satisfaction at some astonishingly poor shooting, so understand the concept of correctly torquing fasteners is completely lost on more than a few.

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do you torque the wheelnuts on the family car???? but they do on heavy trucks.....
why the difference??? because on one it is important,on the other,the strain isnt going to be huge and tight enough is good enough...bit like scope rings really.....
now action screws on a long range precision rifle,in a ridgid chassis, I can understand....the bedding contact may be effected differently ,but not on std stock.

Yes I torque wheel nuts.
Ever since snapping a couple of studs on a work vehicle where someone had over cooked things using their calibrated elbow.
Was a cheap lesson on consequences really.

on your car???? if so you would be only person Ive ever heard of doing it....

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Originally Posted by Micky Duck

on your car???? if so you would be only person Ive ever heard of doing it....

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Kats tires at kiapoi definitely torque wheel nuts on cars to spec, they did with mine :thumbsup:
To be honest I've seen more issues with over torquing on both cars and rifles, so using a torque driver/wrench isn't as silly as you think.

Torque, torque, torque. Why doesn't somebody just do something!

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Originally Posted by Micky Duck

on your car???? if so you would be only person Ive ever heard of doing it....

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Yes.
Although I’d admit if I didn’t have access to a 1/2” drive torque wrench at work I doubt I’d buy one special.
I was happy to invest in a 1/4 drive one for my firearms though.

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Originally Posted by Eat Meater

Given I'll be torquing steel screws (I think) into aluminium rings I agree entirely.

Sent from my SM-A520F using Tapatalk

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what rings did you get?

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Originally Posted by longshot

what rings did you get?

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Talley low ring mounts.

https://www.scopeuout.co.nz/collecti...ow-medium-high

Always identify your target beyond all doubt because you never miss and I will be missed

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Originally Posted by gundoc

Complete waste of time! Just nip them up firmly with a drop of LocTite on the threads (bases only). After fitting literally thousands of scopes over the past 60 years I believe torquing scope screws has about as much validity as getting 72 virgins after blowing yourself up!

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Having said that, I would respectfully suggest that your particular hand is a lot more highly experienced at hitting the 'correct' torque than someone who's come off a lifetime of pedalling an office desk! My viewpoint on it is that the actual torque value is less important that how you bring an assembly up to torque and how repeatable you can hit the same torque and that also applies to how you use a torque wrench. I've seen some people side load a click-type torque wrench to the point that the internals are bound up (this is the cheaper type obviously) and at a check of their work the fasteners were all over the place with some finger tight and some white-knuckled gorilla fashion.

The thing about torque wrenches is that they are just a tool and an idiot can still stuff the job up even with the best tool whereas a good tradesman can do excellent work with a table knife and a meat sabre...

As far as the cars I do torque them, purely for the risk of doing them so tight my beloved can't get the freaking things back off if she has too. She's perfectly capable of swapping a tyre over but what stops her is dickheads at tyre shops not understanding the difference between the torque limiting adapters on their rattle guns and torquing everything up to 6,000,000Nm. I was standing there at one shop when the guy on the next car over grabbed the chattering nut fu*ker and started in on a Honda Jazz. I had the "you're about to fu*k this up buddy" look on my face as the boss walked around the corner (he was doing my job fixing a puncture) and kicked the young fella in the arse. Oi, use the little gun and the manual torque wrench - or you break the studs it comes out of your lunch hour replacing them! Fair call I thought.

I've actually given her a small torque-limited torque multiplyer tool which means getting stupid-tight wheel nuts off is still a one-finger operation, and going back the other way it's internally set to something like 80ftlbs. Woman-friendly tyre tools... Although with the new Outlander she has Mitsi roadside assist - thank you Mitsubishi!

The other issue with overtorquing wheel nuts is steel rims on steel taper nuts both the nut taper and wheel recess will flog and flatten requiring a new wheel and set of nuts. Most commonly seen on Trojan wheels and hubs (the old 5-stud Ford pattern) and I've got about three sets of rooted nuts sitting in the shed from replacing damaged ones!

Spend a few $$ and get one of these...
https://www.aliexpress.com/item/4001...d=9VmDNXcXYjlC

Geezus, that's long (she said!). Yeah, anyway...follow the link to a Shahe digital screwdriver.
Not too dear, and works fine.
I bought one to torque scope rings, mounts, and Oryx alloy 'chassis' bolts.
Seen too many ham fisted sods strip a thread on scope mounts, or overtighten so much that they pinch the scope tube.
Also, don't believe all the 'testimonials' online about the Wheeler (USA, and high priced) gear.
It's been tested and checked...and found to be less than stellar for accuracy.
Plus, don't torque something up to (say) 15"lb and then give an extra tweak 'just in case'. That's a good way to munt threads.

The thing about torqueing wheel nuts on cars, reminds me of when I was a young fella having borrowed the old man's car. I said swiped a fence by getting in the long grass while cornering on a narrow Taranaki back road. That dented the wheel rim so me and my mates changed the tire out but little did I know about tapers on wheel nuts so I ripped two wheels that night!

For those who want a laugh at my expense, the experiment worked perfectly. The theory was sound...apart from the Allen key pinging out of the screws at about 1.6 Newtons no matter what support I gave the axis. Twas too loose a fit to take the full 5kg. I torqued 2 screws this way then used hand tightening for the other 6 based on what felt like 5kg of force on the 41mm mark (assisted by the kitchen scales to get the approximate force). If anything, they're probably underdone.

Like I always tell my kids, there's nothing like the right tool for the job. So regardless of my results I'm still right. [emoji1787]



Always identify your target beyond all doubt because you never miss and I will be missed

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Originally Posted by Eat Meater

For those who want a laugh at my expense, the experiment worked perfectly. The theory was sound...apart from the Allen key pinging out of the screws at about 1.6 Newtons no matter what support I gave the axis. Twas too loose a fit to take the full 5kg. I torqued 2 screws this way then used hand tightening for the other 6 based on what felt like 5kg of force on the 41mm mark (assisted by the kitchen scales to get the approximate force). If anything, they're probably underdone.

Like I always tell my kids, there's nothing like the right tool for the job. So regardless of my results I'm still right. [emoji1787]



Always identify your target beyond all doubt because you never miss and I will be missed

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My offer still stands, and includes bore sighter as well. I put it out there because judging by the content of the thread thus far, there is a high chance you will be second guessing yourself at every accuracy step going forward.

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Originally Posted by gundoc

Torque, torque, torque. Why doesn't somebody just do something!

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ya right gundoc - ya not exactly fitting head back on a bloody lamborghini V10 when one is putting a scope on -

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Originally Posted by Barry the hunter

ya right gundoc - ya not exactly fitting head back on a bloody lamborghini V10 when one is putting a scope on -

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Exactly!
Never knew a torque wrench was needed for a firearm until I joined this forum.

Cylinder heads, main bearings etc l, flywheels I knew about but on a rifle???

A torque wrench only measures the force required to turn a screw or bolt and has nothing to do with how tight it is. Tight threads, dirt, damaged threads all effect how tight the screw is. That’s why head bolts are “torqued to yield” ie turned a set angle.
I would recommend a torque wrench to someone who can’t feel a screw is tight.