PM940V-PDF, It broke... Be Aware... (FYI Precision Mathews)

[B2]

Hi @verbotenwhisky

Thanks for posting. l will keep that in mind when working on my 940M.

Maybe you should look at this on the bright side. These are intentionally made this way and are called sheer/snap bolts! If the bolts were not made to break then when a gorilla, who does not normally use a torque wrench, decided to tighten them up he might just break the low quality cast housing rather than the bolt!

Dave L.

 

[dabear3428]

Hi @verbotenwhisky

Thanks for posting. l will keep that in mind when working on my 940M.

Maybe you should look at this on the bright side. These are intentionally made this way and are called sheer/snap bolts! If the bolts were not made to break then when a gorilla, who does not normally use a torque wrench, decided to tighten them up he might just break the low quality cast housing rather than the bolt!

Dave L.

Verbotenwhisky are you going to let him call you a Gorilla? lol

 

[RJSakowski]

20 lb-ft. of torque on an M16 bolt isn't excessive. Even the lowest grade M16 bolt has a torque spec more than three times that.

 

[verbotenwhisky]

Hi @verbotenwhisky

Thanks for posting. l will keep that in mind when working on my 940M.

Maybe you should look at this on the bright side. These are intentionally made this way and are called sheer/snap bolts! If the bolts were not made to break then when a gorilla, who does not normally use a torque wrench, decided to tighten them up he might just break the low quality cast housing rather than the bolt!

Dave L.

I was using a torque wrench and it snapped at 20ft/lbs. I have discussed with PM and I am sending the bolt back to them, they said this wasn't good...

 

[verbotenwhisky]

Verbotenwhisky are you going to let him call you a Gorilla? lol

 

[MikeWi]

I'm told that the bolt is not designed that way, so I'm hoping this is a fluke since it's the only one like this I've ever seen. IMHO that break is too clean even for a weld (spot or otherwise) to have broken. Awful strange.

 

[verbotenwhisky]

I'm told that the bolt is not designed that way, so I'm hoping this is a fluke since it's the only one like this I've ever seen. IMHO that break is too clean even for a weld (spot or otherwise) to have broken. Awful strange.

Hey Mike, I haven't had a chance to send it yet, we had some bad weather, but it will be headed that way by end of week.

 

[MikeWi]

 

[Weldingrod1]

That's a brittle fracture, based on the surface. I'd check the hardness on the other ones, and I'd consider STRONGLY making a full set of them!

Sent from my SM-S911U using Tapatalk

 

[MikeWi]

I received the broken bolt and It is puzzling to look at. I can understand thinking that it was spot welded together now, but why would that be done? I have to agree with making all three. They are likely from the same batch, so I'm not sure I would trust the others. I can also send you replacements if you like. Once again, this is the only example I've seen, so it's probably a fluke, but it's really strange.