Cracked Spuhr mount

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Gunny Sergeant
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Feb 18, 2017
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Philadelphia, PA
I saw 4 of them break exactly like that last year at various matches.

None of them were noted hard impacts on the scope or mount itself, and all claimed they were torqued properly... Not sure if it was a bad batch of metal or what.

I have started putting a dab of oil on the screws when torquing mine as of late but not sure if that makes any difference.
 

M77

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Oct 17, 2012
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havent seen that one before , but had the top cap have a hairline crack .
dealer took care of it nps
 

nexusfire

Secks fi millimeet
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Sep 9, 2010
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Problem is I have about 6 of these things and I dont remember who I got it from. I wonder if they can just replace the piece that is cracked?
 

kthomas

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Jun 17, 2009
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Yours is the 3rd or 4th thread in as many weeks referencing cracks in Spuhr mounts. So I would say yes, it happens.
There's been a lot of threads lately on Spuhrs with issues, I believe all the previous ones had to do with the ring cap itself cracking on the top. This is the first one with the mount itself cracking. Bit of a worrying development, and I wonder if it's an issue with a bad lot of steel.

Irregardless, I'm sure Spuhr will take care of you. Mile High deals a lot of Spuhr mounts, they might be able to help you even if you didn't buy from them, even if it's just getting you in touch with the right people.
 
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newguy2k3v2

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Sep 16, 2009
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College Station, Tx
I saw 4 of them break exactly like that last year at various matches.

None of them were noted hard impacts on the scope or mount itself, and all claimed they were torqued properly... Not sure if it was a bad batch of metal or what.

I have started putting a dab of oil on the screws when torquing mine as of late but not sure if that makes any difference.
If anything putting oil on the screws would make it more likely to crack if using the same torque value. It would increase clamping force for a given torque.
 

KYpatriot

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Mar 31, 2009
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If anything putting oil on the screws would make it more likely to crack if using the same torque value. It would increase clamping force for a given torque.
This. I learned this the hard way working on diesel engines/turbos. To get the same tension on a bolt you need less torque w lubed threads than without. I assume this will vary with the type of lube. Typical reduction seems to be 25-30% for lubed threads vs dry. See here:
https://www.antiseize.com/PDFs/torque_specifications.pdf
 

bna5017

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Feb 17, 2018
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Threaded fasteners lubricated with anti seize have a different coefficient of friction when compared to fasteners lubricated with oil or thread lockers (which are pretty comparable).

Most torque specs indicate dry or lubricated conditions. If you are going to use anti seize it is a good idea to adjust the applied torque to a lesser value to achieve the target clamp load to prevent a failure. The equation is T (torque) = k (coefficient of friction) * d (fastener diameter) * f (clamp load). You can rearrange to solve for clamp load (f=T/(k*d)) and then use the equation in its regular state to see what torque needs applied for the appropriate clamp load and coefficient of friction.
 

madppcs

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Oct 23, 2011
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Ive had 3 or 4 ring caps crack. Mile High took care of me. Hakan Spuhr is on facebook and will reply directly to you if you message him. Awesome guy to deal with and MileHigh are a great combo