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any pro machinists out there?
Spartacus
Member Posts: 14,415
i'm going crazy trying to find a .578 x 28 tap. my commander has a threaded barrel, from fusion, and that's the size.
i'm told it's standard to 1911 style barrels to maintain wall thickness.
the can i have is metric threaded, smaller diameter than the barrel.
i thought i would just re tap it, as discussed here in another thread.
but it seems like that size tap doesn't exist! i've spent an hour googling it and all i come up with are other posts with the same question....
help!
tom
i'm told it's standard to 1911 style barrels to maintain wall thickness.
the can i have is metric threaded, smaller diameter than the barrel.
i thought i would just re tap it, as discussed here in another thread.
but it seems like that size tap doesn't exist! i've spent an hour googling it and all i come up with are other posts with the same question....
help!
tom
Comments
( LINK )
http://www.shop.com/37+64+28+578+28+6fl+H3+Plug+Tap+Usa+Gun+Smithing-222485030-p+.xhtml
obviously, it CAN be done because you can buy suppressors tapped for that size.
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=217261105
http://www.mcmaster.com/#taps/=b4x6tg
quote:You will see a few of us told you it can't be done.
obviously, it CAN be done because you can buy suppressors tapped for that size.
and your hole size was already too big for the tap to work.
dano, i'd appreciate it if you'd ask your brother about it
thanks
tom
My gut tells me its a standard 1/2-28 thread that was reamed to .578 so the threads would not bind. I use over size drills all the time on some alloys, all it does is diminish the % of thread you have in the hole 85% to 65% etc.
a 1/2 - 28 hole size will be .455-.465. If you reamed the hole out to .578 there would be nothing there but a smooth reamed hole. [;)]
My gut tells me its a standard 1/2-28 thread that was reamed to .578 so the threads would not bind. I use over size drills all the time on some alloys, all it does is diminish the % of thread you have in the hole 85% to 65% etc.
Agreed. But just how much 'percentage loss' of thread bearing surface can an item that heats up during useage withstand?
I'm kinda leery about all this..and I need an edjumication as to why temps won't factor in. Thanks, Joe
I will let you guys hash out the finer points of thread cutting. My offer stands if I have oneto mail out. and I stick to the old machinist data handbooks on percentage of threads. They have never failed me and It seems to me every time I hold those standards set forth I have a good quality product.
This is what I am trying to get through here. He has a can, with a 14mm hole in it, there is absolutely no way a .578 x 28 tap will make good threads. I am done beating the dead horse.
quote:Originally posted by FrancF
My gut tells me its a standard 1/2-28 thread that was reamed to .578 so the threads would not bind. I use over size drills all the time on some alloys, all it does is diminish the % of thread you have in the hole 85% to 65% etc.
a 1/2 - 28 hole size will be .455-.465. If you reamed the hole out to .578 there would be nothing there but a smooth reamed hole. [;)]
Your right .562 is 9/16. What the hell was I thinking![:D][B)]
quote:Originally posted by Duce1
I will let you guys hash out the finer points of thread cutting. My offer stands if I have oneto mail out. and I stick to the old machinist data handbooks on percentage of threads. They have never failed me and It seems to me every time I hold those standards set forth I have a good quality product.
This is what I am trying to get through here. He has a can, with a 14mm hole in it, there is absolutely no way a .578 x 28 tap will make good threads. I am done beating the dead horse.
?
Well with less than a 32`d left of the 14mm drill. I would say there is nothing to cut left.
AT
I will have the boys in shop look it up in the morning and I will let you know.
AT
Nothing to look up ?
14MM equals .5512 size coming off the top of my head.
And the .5781= 31/64ths means you have no metal to cut ?
i know that. as mentioned in an earlier thread, my plan is to thread a new piece and weld it to the can.
i mistakenly bought a 1/2" x 28 tap with that intention, but it's too small.
tom
quote:and your hole size was already too big for the tap to work.
i know that. as mentioned in an earlier thread, my plan is to thread a new piece and weld it to the can.
i mistakenly bought a 1/2" x 28 tap with that intention, but it's too small.
tom
This you can do. You will need to drill out the 14mm hole, past the .578", measure the OD of the tap, it maybe oversized. Weld your piece on first, then drill out your hole for the tap. Hole size should be .535-.545, that needs verified, there is no threads listed that size in the machinery's handbook. If you weld after the tapping, you may have issues with warping. In reality this is a part that I would make a master on a lathe, then cut the threads on a lathe.
i just found some threaded sleeves for the .578, the od is 7/8", so a new mount would have to be made. the can is 1 1/4" diameter so, it's doable. i just don't like putting a steel sleeve in and aluminum housing.
thanks again
tom
What can and what threads does it have?
CP
appreciate the advice!
i just found some threaded sleeves for the .578, the od is 7/8", so a new mount would have to be made. the can is 1 1/4" diameter so, it's doable. i just don't like putting a steel sleeve in and aluminum housing.
thanks again
tom
Did you look for a helicoil?
AT