Sheered off my Dan Wesson scope base screws today

You may have to piclk your battles here.

McMaster only has a couple options in 6-48, lengths are 1/4 and 3/8. BoltDepot's finest pitch #6 seems to be 6-40. The Brownell's link above is probably going to be your best selection.

It looks (from your photo) like you can handle the extra 1/6" of length. That said, you have a fair amount of engagement in the screw you backed out, so the extra length isn't gaining you much.

I'd go with either purple or blue, making sure it's actually tight, and allowing the full 24 hours to set. Remember that that threadlocker is effectively a lubricant when you install it, so your torque requirement is slightly less. Maybe apply a dot with a paint pen on each fastener so you can visually confirm that nothing has moved over time.
Just like what we men like to tell our SO's, once your past a certain point extra length doesn't matter - three full threads of engagement is enough.
If they are 48TPI then if at least1/16" (0.0625) is exposed through the mount (I would ago 5-6 threads to be certain) then the interface will achieve full strength without stripping.

If you go too long then the threads could bottom out before fully clamping the mount to the top strap
 
Where is the neg rep when you need it - anyone even mentioning that evil shit should be banned
You know, for that one I'd almost be proud of it.

BTW, @andrew1220 - no, don't safety wire your firearms.

Save that shizz for your airplane, motorcycle, truck, home dungeon, lawnmower, skateboard, etc. You know, the things that might fall apart under you and really ruin your day...
 

I figured that NES would be more efficiently served for that bitch-slap by a local contractor. Well, at least a good thrown stick. Put a pillow under your shirt- I hear her aim is better if she thinks you are preggo. [devil]

You might be able to get that last one out with a pick or small hard center punch. Don't slip or you get the Glostah stick lady.
 
I broke a screw in a 15.00 wall bracket for a speaker. It was faster and a lot easier to do the removal on my Bridgeport than the BS of a hand drill and center punch. Let me marr for life your 1500.00 Dan Wesson .44 mag revolver with my Dremel. I'm really good with one. LOL
Just the ability to hold the part secure is worth the weight of a solid vise and bench, bigger plus if that “vise” is is attached to a bridge port.
 
I have some Permatex blue loctite and just read the SDS online. Says to use a surface prep cleaner/primer if using on inactive metals such as stainless steel. I looked at their surface prep cleaner and it looks like it's just a degreaser/brake cleaner solvent. So essentially you want the threads dry and ultra clean before using the loctite. Thanks for the tip mac.
I have no idea whats in the loctite primer I just know once I learned of it and how to use it screws on equipment at work stopped vibrating loose. Especially anodized and stainless.
I dont know whats in the parts cleaner we use but it sucks. Its cheaper stuff .
 
We must use different stainless then.
Of course, Tensile Strength is one of many traits a designer cares about when talking about "strength," but it serves as a reasonable point of reference.

Here is a look at some readily available examples on McMaster: (NB: 316 is 110 ksi and A286 is 160. Their unit prices are on the order of the package prices of these samples. Does that count as "special alloys?")
1589220355293.png
 
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#6-48 Minor Diameter: 0.1056 min
Area: 0.0088 in^2
Strength @ 170 ksi - ~1500 lbs
Strength @ 70 ksi - ~600 lbs

So for a #6-48, a lubricated torque of 22 in-lb would give a clamp force of around 1000lb (using a grade 8 or better screw)

I would not use stainless simply because SS on SS is just asking for for it to gall up and seize
 
#6-48 Minor Diameter: 0.1056 min
Area: 0.0088 in^2
Strength @ 170 ksi - ~1500 lbs
Strength @ 70 ksi - ~600 lbs

So for a #6-48, a lubricated torque of 22 in-lb would give a clamp force of around 1000lb (using a grade 8 or better screw)

I would not use stainless simply because SS on SS is just asking for for it to gall up and seize
I ended up ordering the torx screws from Brownells. Hopefully they will be fine as long as I clean the threads well and use loctite this time around.

Unless someone else suggest a different screw?

This is the only 6-48 type screw I could find on Mcmaster
 
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18-8 isn't real stainless steel so that's hardly a fair comparison.

After our personal tools were calibrated by the inspection department they would place a drop of colored nail polish on the adjustment screw. This did a couple of things. It prevented the screws from moving yet was easily removed with acetone and the color would match the month/year of inspection.
 
18-8 isn't real stainless steel so that's hardly a fair comparison.

After our personal tools were calibrated by the inspection department they would place a drop of colored nail polish on the adjustment screw. This did a couple of things. It prevented the screws from moving yet was easily removed with acetone and the color would match the month/year of inspection.
I do the nail polish trick on my motorcycle and good cheep idea to know which ones I tighten, brake cleaner works great as a remover also.
The only problem is the cheap nail polish I bought runs a little to much, to thin, I need to find some thicker stuff because it runs on vertical surfaces, doesn't make a good dot.
ANY RECOMENDATIONS ON GOOD NAIL POLISH AND COLOR. I never thought would ever ask that question
 
Blue loctite 242 should be fine for this application. You can use primer if you want but I think it is either essentially acetone or alcohol, I can't remember. The torque requirement with loctite does not change. Yes it is a lubricant and can help when the starting torque is higher than a final torque, common issue with screws that come with a locking patch already on them where you have to overcome that to get it started. Once it bottoms, the final torque value does not change.

I use carb/brake cleaner on bolt and threaded hole, then air compressor to blow both off before loctite. Blue loctite seems appropriate for this problem. Do NOT use red. And don't throw a bucket of loctite on the bolt, just run a bead down the length of the threads.
 
I do the nail polish trick on my motorcycle and good cheep idea to know which ones I tighten, brake cleaner works great as a remover also.
The only problem is the cheap nail polish I bought runs a little to much, to thin, I need to find some thicker stuff because it runs on vertical surfaces, doesn't make a good dot.
ANY RECOMENDATIONS ON GOOD NAIL POLISH AND COLOR. I never thought would ever ask that question
Lol. No I can’t recommend a color to match your outfit.
 
I use carb/brake cleaner on bolt and threaded hole, then air compressor to blow both off before loctite. Blue loctite seems appropriate for this problem. Do NOT use red. And don't throw a bucket of loctite on the bolt, just run a bead down the length of the threads.
Thanks for the tips. I’ll try avoid dumping a bunch of loctite. Probably take longer to cure if I do?
 
Thanks for the tips. I’ll try avoid dumping a bunch of loctite. Probably take longer to cure if I do?

Nope, it'll just run all over the place and not help. Lots of anecdotal info out on the web, but here's a quote from Permatex - a manufacturer of threadlockers:

Here are eight common mistakes that even some pros make when using a threadlocker:

1. Using too much threadlocker
Threadlockers only need to be applied to the first few threads on a fastener. Tightening the fastener will spread the threadlocker evenly. Using too much threadlocker can cause excess to spill out and migrate to unwanted areas.


Source: Permatex Presents: The Eight Most Common Threadlocker Mistakes


Here's Loctite's application info for 242 blue:
Application: For Thru Holes: Apply several drops of the product onto the bolt at the nut engagement area. For Blind Holes: Apply several drops of the product down the internal threads to the bottom of the hole.

Source: https://dm.henkel-dam.com/is/conten...Blue-242-Carded-Tube-0.20-fl-oz-2018-04-09pdf
 
Thanks for the tips. I’ll try avoid dumping a bunch of loctite. Probably take longer to cure if I do?

Loctite is anaerobic meaning it only cures once it is isolated from oxygen. Here is a quick link I found that explains it: Basics on Anaerobic Adhesives and Threadlockers

So the extra will just make a mess and just the bits on the threads will actually cure. The suggestion above of just a small line/dot is all you need, it will flow around the threads as you tighten the screw.
 
But those screws shouldn't have been in shear - they should have been torqued tight enough for clamping force to stop movement.
I do the nail polish trick on my motorcycle and good cheep idea to know which ones I tighten, brake cleaner works great as a remover also.
The only problem is the cheap nail polish I bought runs a little to much, to thin, I need to find some thicker stuff because it runs on vertical surfaces, doesn't make a good dot.
ANY RECOMENDATIONS ON GOOD NAIL POLISH AND COLOR. I never thought would ever ask that question

Paint pen? Unless u just like nail polish
 
On that large a caliber- its really DW fault. Those are #6-40 screws. They should be #8's with that much weight and recoil on a hand gun. Like the OP said they most likely loosened during firing and then sheered off. You could also use another screw in the back on top of the yoke. The heat from the barrel also might have softened the Loc Tite.
 
On that large a caliber- its really DW fault. Those are #6-40 screws. They should be #8's with that much weight and recoil on a hand gun. Like the OP said they most likely loosened during firing and then sheered off. You could also use another screw in the back on top of the yoke. The heat from the barrel also might have softened the Loc Tite.
Yeah they seem like dinky little screws for the weight of the scope base plus rings plus scope. That steel scope base must weigh at least a half pound alone! Then you add the rings and scope, it's got to be at least 2 pounds of material pulling on those screws.

And I don't fight the recoil at all with my grip. I let the gun flip up as I get better accuracy and don't flinch as bad compared to having a death grip. That's a lot of torque on those screws - especially if they're not tight[laugh]
1589327671663.png

And good point on the heat - hadn't thought of that.

I wonder if I could have DW drill and tap to a larger size screw? Well once they reopen anyway.

You do any of that work Greg?

Thanks for chiming in!
 
Loctite is anaerobic meaning it only cures once it is isolated from oxygen. Here is a quick link I found that explains it: Basics on Anaerobic Adhesives and Threadlockers

So the extra will just make a mess and just the bits on the threads will actually cure. The suggestion above of just a small line/dot is all you need, it will flow around the threads as you tighten the screw.

I don’t think I used loctite but know I used it on my DW 357 scoped setup.
Apparently the Permatex blue threadlocker I have, was made in 2007!?...whoops. Time to order some new stuff.
A9D04D5E-FA42-4C00-802A-F96DE52D680D.jpeg4B988E8D-340C-46F6-A47A-A4D29F361C11.jpeg
 
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