What screw thread f...
 

What screw thread for HW30s  

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KW
 KW
(@kw)
Joined: 2 years ago
Posts: 185
2019-09-10 13:02:18  

Could someone please tell me the original screw thread for the REAR GUARD screw for an HW30s before I stab myself in the face.

My taps tell me that it is between 6-32 and 8-32.  I assume that means it is 7-32 but it could be something mmm...urrgh...mmmet.....urrgh....mmmmmmetric!

One of our vets apparently took his rifle apart.  He lost the rear guard screw for the trigger guard.  The captured nut in the trigger box escaped and pharqued his trigger assembly.  I have it all working but would like to find a $0.20 replacement screw instead of a $10 screw from Chambers.

Thanks in advance.

EXPERIENCE, n. The wisdom that enables us to recognize as an undesirable old acquaintance the folly that we have already embraced.


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ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 448
2019-09-10 13:40:09  
Posted by: @kw

Could someone please tell me the original screw thread for the REAR GUARD screw for an HW30s before I stab myself in the face.

That screw is metric on current rifles, and has been for a long time. I don't remember it ever being an SAE threaded screw. So that would be an M4 x .70 thread pitch, if my memory serves me correctly for that being the designation for a standard pitch in that size.

I'm sure the current screw is a 4 mm screw, but I'm only about 50% sure on the pitch. I believe it's the fine pitch that is .75.

There's a real cheap way to do it though. Just go to Ace and buy a 4 mm screw. If it fits, it's the standard pitch, because they don't carry the fine threaded metric screws.  That will set you back about a dollar if you buy a black-oxide version with an Allen socket head.  You're not going to find the OEM-equivalent head style there.

If it doesn't fit, you'll need to find the .75 version somewhere. That might put you back at McMaster-Carr, or the equivalent. But, I think you have a chance regarding it being the standard pitch.

HTH.

( I don't like to give out bad information. Some of my designations for the pitch as to which is fine and which is course may be incorrect. But I can tell you that I just bought an Irwin standard 4 mm tap, and on the front it says "4 MM-0.70"  It's an Irwin stock number 8317.  And I do think that's the same one carried by local hdwe. stores, like Ace, Home Depot, etc).

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


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marflow
(@marflow)
Joined: 2 years ago
Posts: 631
2019-09-10 14:54:20  

https://www.dropbox.com/s/37xsp29da0s51e3/Wihrauch_HW30.pdf

 

on SEA and metric screw, if the product was made outside the states it will alway be metric

after do some looking this post answer your question and checking Chambers it is the same screw 

https://www.tapatalk.com/groups/yellow/does-anyone-know-the-screw-size-and-thread-pitch-f-t204996.html

so you're looking for a m4 x ..70 x 15mm  that is slotted oval head  machine screw and phillips could work or even allen but not in oval just flat 

 

Mike


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Faucetguy
(@faucetguy)
Joined: 2 years ago
Posts: 81
2019-09-10 16:36:32  

I replaced one on a R1, got it at Ace. Fit perfect.  Hw30 might be a differant animal.


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KW
 KW
(@kw)
Joined: 2 years ago
Posts: 185
2019-09-13 09:43:09  

Thanks folks.

It was indeed M40-70.  The standard pitch worked but was sticky.  I ran it in and back out and may have altered the original pitch, but they both mate nicely now.  And I have two more from the bag.

Had to heat and blue the screw to match.  Couldn't find any black oxide ones at the hardware store.

Thanks again!

EXPERIENCE, n. The wisdom that enables us to recognize as an undesirable old acquaintance the folly that we have already embraced.


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