Author Topic: Grip Screws  (Read 3153 times)

Offline 3kushn

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Grip Screws
« on: November 24, 2008, 11:06:32 AM »
I'm waiting for delivery on my new R9 and it's a tough wait but will be over very soon.  

I've been reading up on the weapon and saw I need to be sure the right side grip screws are tight.  How tight is tight.  Is there a torque spec on this?  Is there a tightening procedure ie torque then let set for a while then re-torque. Do they tend to back out after firing X# rounds?  How often should I need to inspect them?  Daily, 100 rounds, 500 rounds?


Offline Richard S

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Re: Grip Screws
« Reply #1 on: November 24, 2008, 07:42:15 PM »
3kushn:

Welcome to the Forum, and congratulations on selecting the R9. You won't regret it.

As for the tightness of the grip screws, I just keep mine what I might call "snugged down" so as not to strip the screw heads. I also inspect them for tightness after every range session. And be sure you use a fine quality hex key.
(1963-1967) "GO ARMY!"

Offline 3kushn

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Re: Grip Screws
« Reply #2 on: November 24, 2008, 08:00:18 PM »
Thanks for the info. I thought that would be the case.

I'm in the torque tool business now but have been in the hand tool business for many years. USA made socket screws must be by law 12.9 spec. Very Hard, although maybe not harder than hardened S2 tool steel that quality keys are made of.  Never looked at whose harder.   12.9 is harder than grade 8 but am not saying that harder is always better.  Depends on the joint.  

I will also tell you that Old Man Allen was a pretty sharp dude. He knew that metals are elastic and no matter how much force you apply to his keys you can only get a certain amount of torque.  Try to get more and the key bends.  So with small keys, when the key flexes you're home.  Not as accurate as a torque wrench/screwdriver, but with quality keys you're darn close.

Suppose till I hear different, every session I check.

Thanks again
« Last Edit: November 24, 2008, 08:07:52 PM by 3kushn »

Offline alligosh

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Re: Grip Screws
« Reply #3 on: November 29, 2008, 01:41:55 AM »
I had a session of testing varios ammo and got about 100 rounds through when is started failing to fire on every round. Ended up that I had lost one of those screws.  Rohrbaugh suggests the medium locktight if that happens.

So far, keeping the screws tight and using ammo that uses Winchester primers, everything seems great.

Offline jetman

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Re: Grip Screws
« Reply #4 on: December 05, 2008, 06:25:57 PM »
I THOUGHT I had my grips screws tight after swapping out my G10 grips for a set of blue Carbon Filber grips I bought. I took it to the range and shot about 2 mags through it and the trigger spring came loose under the grips, causing the trigger not resetting ... and turning my pistol into a very expesnive paperweight. I brought it home took the grip panel off and re-connected the trigger spring, re-installed the grips and now the trigger works again..... this time I hope for more than 12 rounds the next time I take it to the range though. I torqued them about as tight as earlier described to when the wrench started to arc. Hopefully that will be sufficient or I may have to use the Lock-tite or go back to the factory grips. I wish someone made QUALITY screws with torx head fasteners or a larger size allen screw.
« Last Edit: December 05, 2008, 06:27:01 PM by jetman »

Offline 3kushn

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Re: Grip Screws
« Reply #5 on: December 05, 2008, 08:29:17 PM »
Today I fired off about 75 rounds (finishing off a 100 lot) and on 3 or 4 occasions the trigger didn't reset.  I just thought it was me and could have been. but I haven't checked the screws yet.
I'd guess at around the first 35 rounds, ever shot, out of this gun, I got this.

The possible issues with the screws are:  But I want to mention that I have not looked under the grip yet.  
PLUS
This writing is based on generalities.  I am not a gunsmith, in fact know ALMOST NOTHING about guns, and have absolutely no intimate knowledge of the R9.  The only thing I do know is "torque."  THAT'S IT. Except firing a total of 100 rounds out of my personal R9.

Under ideal circumstances when a screw or bolt is properly installed it must stretch just slightly and will act like a rubber band giving tension or "Clamping Force" to the joint.  The amount of tension that a fastener can exert is determined by the tensile strength of the material.  If a fastener is not torqued/tensioned properly there will be issues.  1) UnderTorqued/tensioned it could back out.  Over Torqued/tensioned it could enter into what is called it's "plastic state" which weakens the screw and could break.  An over torqued screw will never be able to give you the clamping force that it was designed to give.  Screws or Bolts backing out or breaking is the reason torque is so important on critical joints.

Joint design also plays a role in determining proper torque for a given fastener.  

With this application we have a stainless steel flat head screw holding a piece of carbon fiber.  The geometry of a flat head is not the best with regards to strength and clamping power.  The Button head is the only design that's weaker.  A socket head cap screw is the strongest design and would probably solve the problem especially if the grip plate were also a hard material.  7000 series aluminum may  be hard enough.  But with Socket head caps the entire grip would have to be much thicker unless you didn't mind the heads sticking out beyond the grip.  I don't think so.  The other solution is not to use Stainless Steel screws.  Stainless doesn't comply with 12.9 spec for socket screws, meaning stainless doesn't have the tensile strength/clamping force of the standard alloys used for socket screws.  But standard alloys will rust.

All in all it's a real challenge and I can appreciate what they've done.  What I've read is that the gun was not designed to shoot a lot.   For me it's one of two things.  A primary gun where ultimate concealment is absolutely needed or and usually a backup, so small that you could forget it was even there until needed.

I will warn anyone, unless the design engineers for this weapon suggest that it's OK.  DO NOT CHANGE ANYTHING WITH REGARDS TO THIS ISSUE.  DO NOT BUY OR USE STANDARD 12.9 FASTENERS WITHOUT PERMISSION FROM THE FACTORY.  They have spent years developing and refining this tool. Only world class gunsmiths and the factory will have the know how to suggest or implement design changes.


Offline theirishguard

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Re: Grip Screws
« Reply #6 on: December 06, 2008, 12:15:42 PM »
good information, thanks for posting it.  Tom
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