Rifle Scopes Stripped a Spuhr Mount Screw During Install

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Yerman

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Jun 15, 2013
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Fort Worth, Texas
#1
So I just stripped one of the bottom screws (mount to base) of a Spuhr mount while installing it on a new rifle.

I was using a perfectly sized torx bit and a Wheeler fat wrench. 20 in/lbs on the rings went perfect, 45 in/lbs on the bottom screw to attach the mount to the base and it rounded over at what I believe to be around 30-35 in/lbs range. I was able to push hard enough to get a single click on the wrench but when I tried to get a second click on the wrench, it completely rounded over.

Anyone else have this issue? The bolt head felt very soft.

Here is the wording from the manual “
Torque values for ring screws are 15-25 in/lbs (1,9-2,9Nm) and 45 in/lbs – depending on scope manufactures recommendations.
(5 Nm) for the side clamp.”
 
#9
The problem with torx screws is it can seem like you are using the correct one when in fact you are probably using the next size down from the one you are suppose to be using. With torx screws I always start big then work my way down to the one that will actually go in the screw. Spuhr includes extra ring cap screws, but for the life of me I don't get why they don't include a couple extra base screws also.
 
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#10
Palmetto-Pride said:
The problem with torx screws is it can seem like you are using the correct one when in fact you are probably using the next size down from the one you are suppose to be using. With torx screws I always start big then work my way down to the one that will actually go in the screw. Spuhr includes extra ring cap screws, but for the life of me I don't get why they don't include a couple extra base screws also.
Click to expand...

that is really true. I have a set of Torx drivers and Hex drivers side by side at my workbench. The hand held T variety. I am back and forth and with light and magnifier with the Torx. When you get it right, it is no issue, but many times picking undersized. Hex drivers much less of an issue, but they can slip.
 
#11
I just did the same thing, I'm sure now it was probably the wrong size torx.

Rushing the night before my first match and tired old eyes. Damn!
 
#15
Palmetto-Pride said:
The problem with torx screws is it can seem like you are using the correct one when in fact you are probably using the next size down from the one you are suppose to be using. With torx screws I always start big then work my way down to the one that will actually go in the screw. Spuhr includes extra ring cap screws, but for the life of me I don't get why they don't include a couple extra base screws also.
Click to expand...
Thats exactly what I did!
 
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#23
Slick66 said:
Yep, Torx heads

Stripped head and stuck bolts, not the same thing. Torx bolts/wrenches fit just well enough to let you think you’re using the right size, until...you put the juice on it.
Click to expand...

My response had no bearing on none of the above, guy just wanted to know what an easy out was.
 
#24
So what size T bit are you supposed to use on the ring and base screws? I just stripped a ring screw and it isn’t the first time. Fucking frustrating they can’t just put it in the instructions
 
#25
tsu45 said:
So what size T bit are you supposed to use on the ring and base screws? I just stripped a ring screw and it isn’t the first time. Fucking frustrating they can’t just put it in the instructions
Click to expand...
I like: stamped/engraved into the mount. Seen one or two things do that, and for critical stuff I may have to do in the field or bent around in the dark, I write the size and (if applicable) torque setting next to it. No loosing the instructions then.
 
#26
I see variation in these screws. I have ~ 12 spuhr mounts - so thats 4-5 T20 cross bolts screws per mount so thats ~ 60 screws i have tighted to my picatinnies. Of those 2 screws (1 today) had imperfections in the torque head that didnt allow my T20 to tighten it. Same T20 head (fix it sticks) fit 4 of the base bolts but the 5th one was mushy. So there is definitely some defective bolts coming through - ~ 2% on my small sample size.
 
#27
I have a number of Spuhr mounts and I am entirely satisfied with them. However, I cannot understand why manufacturers choose Torx head fasteners over plain old Hex/Allen head. Granted, Torx looks sexier.
Think about availability of replacement parts in the field/Barney Fife's local hardware store. Same reason that when I had my boat, I replaced every existing slotted stainless screw with Phillips heads. Don't even get me going on the jag offs at local boat dealers that insist on rigging new motor installs with NF Nuts and bolts. If something goes haywire and you need a replacement, your local hardware store simply isn't going to have it. I agree that NF nuts and bolts are better (particularly on airplanes), but availability sucks.
 
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#29
shoobe01 said:
I like: stamped/engraved into the mount. Seen one or two things do that, and for critical stuff I may have to do in the field or bent around in the dark, I write the size and (if applicable) torque setting next to it. No loosing the instructions then.
Click to expand...
It’s why I paint the torque spec on my mounts with red Testors enamel at the same time i put the index marks on the screws. Save yourself some grief and paint the values on yourself!

Cheers, Sirhr
 
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#30
Threadcutter308 said:
I have a number of Spuhr mounts and I am entirely satisfied with them. However, I cannot understand why manufacturers choose Torx head fasteners over plain old Hex/Allen head. Granted, Torx looks sexier.
Think about availability of replacement parts in the field/Barney Fife's local hardware store. Same reason that when I had my boat, I replaced every existing slotted stainless screw with Phillips heads. Don't even get me going on the jag offs at local boat dealers that insist on rigging new motor installs with NF Nuts and bolts. If something goes haywire and you need a replacement, your local hardware store simply isn't going to have it. I agree that NF nuts and bolts are better (particularly on airplanes), but availability sucks.
Click to expand...

Because Torx is a significantly better design. If you use the wrong size bit you’ll have issues, but the same is true of hex. If you’re using the proper tools torx results in less slippage and rounding, and more torque.

We’d all still be using flathead for everything (I’d argue we should have skipped Phillips) if everyone thought that way re: local store availability. All vehicles have moved to torx and many of the nicer screws have as well, so it shouldn’t be long that you see a few complement of fasteners at your local stores.

For what it’s worth, I can’t find fasteners of all types at my local stores, so I think that’s a bad metric. I’d prefer torx 10/10 times over hex. All of my machine work which requires fasteners is all torx now.
 
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#31
ormandj said:
Because Torx is a significantly better design. If you use the wrong size bit you’ll have issues, but the same is true of hex. If you’re using the proper tools torx results in less slippage and rounding, and more torque.

We’d all still be using flathead for everything (I’d argue we should have skipped Phillips) if everyone thought that way re: local store availability. All vehicles have moved to torx and many of the nicer screws have as well, so it shouldn’t be long that you see a few complement of fasteners at your local stores.

For what it’s worth, I can’t find fasteners of all types at my local stores, so I think that’s a bad metric. I’d prefer torx 10/10 times over hex. All of my machine work which requires fasteners is all torx now.
Click to expand...
From a manufacturability standpoint, yes, Torx has clear advantages. My point is from that of field replacement. Where locally are you going to find Torx fasteners that are even remotely close to what is used on a Spuhr mount ? Yes, you can get great aftermarket service from Mile High, but even under the best of conditions,you will be waiting for 24 to 48 hours for delivery of replacements.
Torx bits/wrenches are becoming more common from a commercial availability standpoint (local hardware store), but hex/Allen head Is far more common.

What doesn’t hurt Torx and doesn’t help Allen heads is that field failure is pretty uncommon to rare. So, the subject of field failure/serviceability doesn’t come up very often.
 
#33
Assuming the torx bit you use is the correct size (and not worn out), there shouldn’t be a need to find replacements. Keep in mind cheap torx bits that come from Harbor Freight, or the plastic tub at the hardware store aren’t made with precision, and will cause damage to the heads. The same goes for the cheap hex/Allen keys/bits. All the German cars I work on have torx and hex head fasteners, and I only use the expensive tools on them, because the cheap torx/hex bits always lead to damaged fasteners. For example I have a set of Harbor Freight T-handle hex keys that I bought for gun projects, because I figured the small torque values used on most gun accessories wouldn’t require using my expensive tools at work. However, I found that the keys themselves were often ever so slightly undersized, and were marring some of the fasteners I was using them on. Particularly alarming was a stripped Allen screw on my PRI top rail. I consequently bought a US made set of Allen keys from Ace Hardware, and found they fit the screws on the top rail MUCH better than the cheap Harbor Freight stuff. Moral of the story is use a quality bit that is not worn out, and use the correct torque value, and you should be good to go.

I’m not trying to be preachy, I’m just trying to help. We spend good money on our stuff, why chance damaging them by using cheap out of spec tools?
 
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#34
Hammer_Man said:
Assuming the torx bit you use is the correct size (and not worn out), there shouldn’t be a need to find replacements. Keep in mind cheap torx bits that come from Harbor Freight, or the plastic tub at the hardware store aren’t made with precision, and will cause damage to the heads. The same goes for the cheap hex/Allen keys/bits. All the German cars I work on have torx and hex head fasteners, and I only use the expensive tools on them, because the cheap torx/hex bits always lead to damaged fasteners. For example I have a set of Harbor Freight T-handle hex keys that I bought for gun projects, because I figured the small torque values used on most gun accessories wouldn’t require using my expensive tools at work. However, I found that the keys themselves were often ever so slightly undersized, and were marring some of the fasteners I was using them on. Particularly alarming was a stripped Allen screw on my PRI top rail. I consequently bought a US made set of Allen keys from Ace Hardware, and found they fit the screws on the top rail MUCH better than the cheap Harbor Freight stuff. Moral of the story is use a quality bit that is not worn out, and use the correct torque value, and you should be good to go.

I’m not trying to be preachy, I’m just trying to help. We spend good money on our stuff, why chance damaging them by using cheap out of spec tools?
Click to expand...
Yep, exactly. No sense whatsoever in cheaping out on tools that are so relatively inexpensive to begin with.
 
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#37
I also stripped a base screw, and also noticed the softness with the other 4 base screws in my SP-4001. Called into Mile Hile Shooting for a replacement set, and never received them (if they were actually shipped).

Ended up ordering some heavy duty allen head screws from Amazon to replace my base screws, and now I have more than enough spares for other Spuhr mounts. These work perfectly, extra sturdy, and can be removed with pliers if they should ever strip (which is doubtful).

 
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#38
For ALL fasteners, and many other things, start with McMaster Carr

www.mcmaster.com

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
www.mcmaster.com www.mcmaster.com

Often cheap enough it's no big deal to buy their minimum quantity of 25 or 100, even if you only need 4, but I have a whole wall of Akro bins of fasteners so maybe that's just me.
 
#40
#43
Mile High usually has screws, that’s where I got them from for my ST-3701. I found that there are two different head thicknesses for the base screw, I think I have some of both and can take pictures tonight if anyone is interested.

Edit to add picture of Spuhr base screws.

ED2A334E-707C-4F19-86CB-57986A50CA7D.jpeg
 
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