WTB long 3/8-16 tap
- Thread starter cueguy
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You can get them here.
http://www.cuestik.com/
http://www.cuestik.com/
I posted this in your other thread as well:
Larry,
You can purchase a 'nut tap', 3/8x16x6"OAL for about $15 + s/h.
What you then need to do is to reduce the diameter of the shank behind the flutes/threads to just less than the dia. of the tap-drill. In this case, anything less then .3125".
I don't know why you would need an 8" tap for wght. bolts. The longest I ever use is 5" and very rarely. If you want heavier than that, go to a larger dia.
Larry,
You can purchase a 'nut tap', 3/8x16x6"OAL for about $15 + s/h.
What you then need to do is to reduce the diameter of the shank behind the flutes/threads to just less than the dia. of the tap-drill. In this case, anything less then .3125".
I don't know why you would need an 8" tap for wght. bolts. The longest I ever use is 5" and very rarely. If you want heavier than that, go to a larger dia.
Info
KJ,
Thanks for the info. A friend had asked if I could make the hole a little deeper and tap it so he could move the bolt a little farther in to change the balance point just a hair.
Appreciate your info!
Larry
KJ,
Thanks for the info. A friend had asked if I could make the hole a little deeper and tap it so he could move the bolt a little farther in to change the balance point just a hair.
Appreciate your info!
Larry
easy
Any decent machine shop supply will carry a long tap. I bought a ten inch tap to go into a hole 8 inches. Most taps have a center hole in both ends. Just chuck up on the shank near the square end, and spin it with a live center holding the business end. Then use a good carbide bit : slowly cut the shank to 5/16 or so.
BUT do yourself a favor before you cut the shank: chuck up on that shank, near the threaded end, before you cut that shank and cut the nose of the tap so you can press on a ring of steel. then cut that to 5/16 inch size. Now you have a nose on that tap to guide it in that long hole. After you then cut the rest of the shank, leaving maybe a couple inches at full diameter near the square end, you have a great tap for cuemaking that is not offered anywhere else. You will need an extended nose live center to hold the tap centered and cut very slowly with a good carbide bit. All my common taps now have a lead in nose like that and they work great for cuemaking. And it did not cost an arm and a leg.
Any decent machine shop supply will carry a long tap. I bought a ten inch tap to go into a hole 8 inches. Most taps have a center hole in both ends. Just chuck up on the shank near the square end, and spin it with a live center holding the business end. Then use a good carbide bit : slowly cut the shank to 5/16 or so.
BUT do yourself a favor before you cut the shank: chuck up on that shank, near the threaded end, before you cut that shank and cut the nose of the tap so you can press on a ring of steel. then cut that to 5/16 inch size. Now you have a nose on that tap to guide it in that long hole. After you then cut the rest of the shank, leaving maybe a couple inches at full diameter near the square end, you have a great tap for cuemaking that is not offered anywhere else. You will need an extended nose live center to hold the tap centered and cut very slowly with a good carbide bit. All my common taps now have a lead in nose like that and they work great for cuemaking. And it did not cost an arm and a leg.
Great info!
This is such a fantastic place. Anytime you have a question, you can get many different perspectives to help out quickly.
Thanks for all the ideas!
Larry
This is such a fantastic place. Anytime you have a question, you can get many different perspectives to help out quickly.
Thanks for all the ideas!
Larry
The piloted tap is a novel idea for keeping the threads being cut, centered in the hole. But it's all dependent on how straight the hole is. If the tap/drill wandered slightly during the drilling process, the tap will follow that hole; even if it's 'bent'. The wght. bolt, not so much.
Maybe a 5/16" coring/gun drill would be an improvement for this application.
Carbide may be worth a look as well. Neither of these drills are cheap.
Hello eBay.
Maybe a 5/16" coring/gun drill would be an improvement for this application.
Carbide may be worth a look as well. Neither of these drills are cheap.
Hello eBay.
For common thread taps of longer length, just search MSC (or whomever you like) for "pump taps" as these are longer shank taps that are (typically) turned under tap drill diameter.
Note the longer the tap, the less stable, so keep that in mind...
My Dad made some 'custom length' ones by brazing on a piece of (slightly over shank diameter) steel to the end of a normal tap as well. Grab the tap thread OD in your collet and turn the over-size 'shank extension' down to size so it remains straight on the thread centerline.
Note the longer the tap, the less stable, so keep that in mind...
My Dad made some 'custom length' ones by brazing on a piece of (slightly over shank diameter) steel to the end of a normal tap as well. Grab the tap thread OD in your collet and turn the over-size 'shank extension' down to size so it remains straight on the thread centerline.
Where do you find these long bits? I've tried MSC, Travers, Enco, J and J, General and even tried to special order from Fastenal. They all said 6 inch tops. I've tried turning down taps before using single point without much success. The longer taps just deflect away from the tooling and the short ones will cut a little they mostly just smoke. I've had most success using a tool-post grinder with a stone. Takes a while but eventually gets the job done.
Dick
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long taps
I bought my 10 inch long 3/8X16 taps from Quality Tools, local machine shop supply, same place I sent you guys to buy those carbide inserts with the high rake angle for wood.
The tel number is: 440-975-9684 and ask for the tool counter person.
That 10inch 3/8x16 tap is part number EM72-616 from page 294 in their 2009 catalog, and price is: $22.75. It is an import. 3/8 is the smallest of their 10 inch taps. Though they have taps down to #6 in 8 inch!
I never had a big problem cutting the taps with a good carbide insert for hard steel. It just took patience. I think I also chucked up close to the cutting area and cut 2 inches or so at a time so the cut did not push off as easily. Not as nice of finish as a grinder can do, but way good enough for the task needed. You might also consider using a follow rest while cutting? But I did not need to use one, just took my time with a very slow fine feed.
The nose cut took the slowest feed as it is super hardened.
I also see on the next page of the catalog, an 8 inch long Reiff& Nestor tap with the shank sized down to .275 from the factory, in 3/8X16 size for about $40. But they do not list any over 8 inches long in that brand. Hope that helps out some of you.
I bought my 10 inch long 3/8X16 taps from Quality Tools, local machine shop supply, same place I sent you guys to buy those carbide inserts with the high rake angle for wood.
The tel number is: 440-975-9684 and ask for the tool counter person.
That 10inch 3/8x16 tap is part number EM72-616 from page 294 in their 2009 catalog, and price is: $22.75. It is an import. 3/8 is the smallest of their 10 inch taps. Though they have taps down to #6 in 8 inch!
I never had a big problem cutting the taps with a good carbide insert for hard steel. It just took patience. I think I also chucked up close to the cutting area and cut 2 inches or so at a time so the cut did not push off as easily. Not as nice of finish as a grinder can do, but way good enough for the task needed. You might also consider using a follow rest while cutting? But I did not need to use one, just took my time with a very slow fine feed.
The nose cut took the slowest feed as it is super hardened.
I also see on the next page of the catalog, an 8 inch long Reiff& Nestor tap with the shank sized down to .275 from the factory, in 3/8X16 size for about $40. But they do not list any over 8 inches long in that brand. Hope that helps out some of you.
Thanks, I have and use the 3/8X16 almost daily but have been wanting to get a little larger size. and haven't been able to find one.
By the way, I ended up getting those cutters from another source but they sure are the nuts. As soon as I saw one when Willee made the post I knew they would be perfect. Thanks for that info also.
Dick
I usually end up only needing shorter weight bolts, and the 7" tap usually gets the head of them close enough to the handle for me, so that all the weight is not at the very back, but With the 7" and under taps a good portion of the tap length is wasted in the dead space of the sleeve just getting to the area to be tapped. It's too bad they don't make a really accurate extension, or a accurate coupler couldn't be made, because that would sure save a lot of extra work, but making such a thing, although not hard to do, It still may be hard to get a finished product that is as accurate as solid tap, therefore not worth the effort I suppose.
I would like to have a 10" tap though, and really appreciate the info given here. If I can find one maybe I'll give it a shot, but out of curiosity a few questions come to mind, would It be better to grind the shank? If I made a mount to go on My metal lathe to hold a dremel or PC trimmer, would that be enough to get away with a few grinding jobs? and what would be the best kind of grinding stone for that kind of stuff? Or are those not feasible at all, and should I only use a dia grinder due to the sideways force induced?
I would like to have a 10" tap though, and really appreciate the info given here. If I can find one maybe I'll give it a shot, but out of curiosity a few questions come to mind, would It be better to grind the shank? If I made a mount to go on My metal lathe to hold a dremel or PC trimmer, would that be enough to get away with a few grinding jobs? and what would be the best kind of grinding stone for that kind of stuff? Or are those not feasible at all, and should I only use a dia grinder due to the sideways force induced?
I just put a .250 shank grinding stone in my router and run the lathe slowly back and forth to get sufficient clearance. I have a 12inch brad tipped drill bit which I would like to find a replacement for. I've seen the sets of long brad point bits but they only have a short spiral on them for removing chips. The one I use has the spirals almost the entire length.
Dick
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Thanks, I may make a mount and give It a shot. It would be useful for making other tooling also, so I'm sure i can find some things around here to try grinding at first.
I need a good bit also, The one I have is actually longer then needed, and not even a brad point. It walks on Me some, but gets the job done. I do need something more accurate with better chip removal. It works pretty good for drilling a pilot for coring, but then I come back and bore with a long bar from both sides, so the pilot centering is not as important. I don't core a lot so still haven't got a gun drill yet, and that's My only way to do it right now.It's not exactly the easiest way, but works, and to My surprise the 2 bores actually line up well If I indicate things correctly when switching sides.