Sportsmatch failure

[Formidilosus]

I watched that the other day. I would guess the loctite could have changed the actual torque value, but I don’t know how much. I used to never use it, and did on these and had an issue. I used loctite again with the UM rings but the screws feel much stronger. I also didn’t use their recommended torque of 25 pounds, just 20.

Your scope will slip at 20 in-lbs in UM rings. You have been fed a bunch of BS about ring torque specs- the screws size and thread pitch determine how much torque results in a certain clamping force of the scope tube. 20 in-lbs on the UM rings is equivalent to approx 10 to 12 in-lbs in normal rings.

For UM Tikka rings:

28 in-lbs equals 18 in-lbs clamping load of Nightforce UL rings.

32 in-lbs equals 20 in-lbs in NF UL rings.

 

[Formidilosus]

If using loctite you (OP) are probably getting much higher actual torque. See starting at ~16:47

Video

Edit: I’ve seen material indicating it does change torque to others saying always reduce by 20%. I don’t know the answer. I do know any lubricant changes the applied torque, and Loctite sure seems to have some lubricant qualities. Food for thought.

No. Blue loctite has a maximum K value of .2; it less lubricating or slippery than the oil that comes on ring screws that half the manufacturers tell you not to remove.

Finger nail polish or a paint pen is a near zero K value.

 

[fmyth]

View attachment 714444View attachment 714445Some of you had me questioning my wrench, and I won’t argue that it may be out of spec, but I set it at 20ish pounds and took the other cap screws off. It never offered to slip so I would assume it’s I was closer to 15 than 20 when installed.

Do you set your torque wrench back to zero before you put it away?

 

[Pickettpuncher]

Do you set your torque wrench back to zero before you put it away?

Always

 

[SDHNTR]

If using loctite you (OP) are probably getting much higher actual torque. See starting at ~16:47

Video

Edit: I’ve seen material indicating it does change torque to others saying always reduce by 20%. I don’t know the answer. I do know any lubricant changes the applied torque, and Loctite sure seems to have some lubricant qualities. Food for thought.

That video shows the use of anti seize affecting torque values, not Loctite. Anti seize is grease. Huge difference

 

[prm]

That video shows the use of anti seize affecting torque values, not Loctite. Anti seize is grease. Huge difference

As stated, neither are true lubricants, but both impact the friction and thus the actual torque compared to dry metal. Torque recommendations are based on dry metal. Anything done to reduce friction transfers some portion of the torque being applied to bolt tension from overcoming friction. The point is, the resulting bolt tension from clean, dry threads to loctite/oil/anti seize, etc., is going to be higher. Maybe a little, maybe a lot.

 

[Macintosh]

As stated, neither are true lubricants, but both impact the friction and thus the actual torque compared to dry metal. Torque recommendations are based on dry metal. Anything done to reduce friction transfers some portion of the torque being applied to bolt tension from overcoming friction. The point is, the resulting bolt tension from clean, dry threads to loctite/oil/anti seize, etc., is going to be higher. Maybe a little, maybe a lot.

Yes, but as-supplied the screws do not come
dry, they are oiled. There was a recent thread where we contacted several ring manufacturers that recommend against using threadlocker about this, and they all responded that the clamping force wet wasnt an issue, that they simply had lots of customer service and return issues with gummed up threads.

 

[Telford29]

I am getting ready to install UM rings on a couple tikka rifles. My question is, do I pull the screws out of the dovetail clamps to add a little thread lock, or is it just recommended for the top ring screws? I assume that you do not need thread locker on the little threaded pins that go into the action. I did watch the installation video Jason made but was looking for a little more clarification on the base (clamp) screws. Thanks to anyone with some insight on this.

 

[crich]

This is surprising as I've pulled screws (without heat) from 2 sets of sportsmatch rings that I accidentally used red loctite on super late at night past my bed time. Didn't realize it until I bent an allen wrench removing them months later. They were a bitch to get off but I chased the screw threads and have been using them with no issues since.

 

[Pickettpuncher]

I am getting ready to install UM rings on a couple tikka rifles. My question is, do I pull the screws out of the dovetail clamps to add a little thread lock, or is it just recommended for the top ring screws? I assume that you do not need thread locker on the little threaded pins that go into the action. I did watch the installation video Jason made but was looking for a little more clarification on the base (clamp) screws. Thanks to anyone with some insight on this.

I used the loctite and pulled the screws to apply on the UM rings I used to replace the sportsmatch