doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com BSA hinge

Does anyone know whether the hinge (cross) pin on BSA boxlocks is threaded with a left hand thread?

Reason for asking is the failure to remove the pin by a professional who treated it as a normal thread (ie right hand) but failed to budge it even with specially made tools.

It crossed my mind that perhaps the pin is threaded with a left hand thread and he might have been tightening it unwittingly.

That can't be ruled out but very, very unlikely. Generally there has to be a good reason for left hand threads. In this case the gun maker would also have to make a LH tap. Possible, but why? Soak it in penetrating oil, heat it up, use an impact driver, do all the stuff that top notch screwers do to get unscrewed.
nial

Be sure to check very closely that there is no screw or pin, holding the hinge pin in place.
Mike

Mike, I would hope that's the first thing a "professional" would check since it's not uncommon to have a set screw going cross wise from the front of the knuckle into the hinge pin. Can you imagine a "professional" who missed that. Scary, boys and girls.
nial

[quote=nialmac]Mike, I would hope that's the first thing a "professional" would check since it's not uncommon to have a set screw going cross wise from the front of the knuckle into the hinge pin. Can you imagine a "professional" who missed that. Scary, boys and girls.
nial


Actually yes

Joint pins can be an absolute nightmare to get out on occasion .
Some are so loose they virtually fall out and some mo matter what just dont want to budge without some serious brute force .Not unknown to have to be drilled out when all else has failed .

Hi shotgunlover.

What I am about to describe is somewhat brutal but it has an extremely good chance of helping you remove a seized rusted and other reasons that make screw threads virtually impossible to move. It does involve heat but in a very specific way applied to the joint pin its self. You will need a stick welder not a Mig or Tig just a standard coated electrode welder capable of providing a couple of hundred amps. You attach a carbon rod (the copper coated type used for ark brazing) to each output cable of the welder then apply the carbon rods to each side of the guns hinge pin then turn on the current. You will find that the steel pin will start to heat up because the steels electrical resistance is far higher than the copper wire of the welder leads plus the carbon rods, If you keep the connection on long enough you can get the joint pin red hot. This method has been used for many years for removing rusted or generally seized bolts nuts and studs but things do get hot so not for the feint hearted!

Batshit. You know as much about the SMAW aka "Stick" rod electrodes, polarity settings, carbon, copper and mild steel resistance to amperage flow, as old Neville Chamberlain knew about what made Hitler what he was- You can't do thus, as you describe, with the usual Lincoln Electric red "buzz box"transformer arc (not ARK-think Noah and the Bible with that spelling) welder most farmers and hobbyist metal workers here in the colonies have- why, might you ask, my ill-informed Limey- because the buzz box welders- fed with 220 single phase input current and a 10% duty cycle welding machine (except for the 75 amp setting-encircled on the front panel, by the way_ you need a 440 3 phase input transformer or rectified DC welder with a 100% duty cycle- with at least a 350 ampere output at 100% duty cycle- such as metal fabrication plants that tend to join heavy gauge steel with 7014 or 7018 AWS code rods, 3/16" to maybe 1/4" in dia. and run in the 1G or downhand position- If some beginner here who doesn't know this tries your suggested proceedure, he will not be pleased with his end results==

Fox,
I find it pretty hard to believe that our learned friend, n my fellow countryman , Damascus has posted a load of bullshit...I'd bet what he said, if done as he says , will work fine.
Perhaps its the Separated by a common language thing?
franc

Well fox you never cease to amaze me, you have thrown all the technical though miss guided chaff in the air. Possibly caused by the �Not thought of by me syndrome� and my final word on this subject is this, high current applied using low resistance conductors through as in this case steel with more resistance than the conductors will always produce heat depending on the current flow applied, all governed by the emf. THIS IS HOW A SPOT WELD IS PRODUCED in steel.
So don�t knock it if you have never tried it please. Because what I described in my posting was a very large spot welder without the timer as you should know!!!!

Damascus