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Since dull taps breaks easily specially on Stainless Steel. How many times can it be used before replacing it with a new one?
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Small taps
- Thread starter Ang_Panday
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Just kidding. I guess it really depends on the thickness, hardness, type of steel, etc. I have some taps that I've been using for years, others after 10 or 20 times are shot...
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Carbon taps break sometimes on the first use. They are not my personal fave. Get HSS (high speed steel) taps from micro fasteners and you can get a lot more use out of a tap. I've used the same 2-56 tap all year if that is any example and believe me it gets the tar used out of it..
Don't ask me how many times I've threaded knives for clips or made new knives needing threads. I haven't counted but my shop is not at a stand still for sure. I've used that threader in everything from brass to aluminum, titanium and other materials like micarta, G10 and G11 and more. I've lost count.
I will say how long the taps last depends on the proper drill size you use. For example with the 2-56 size screws on really thick titanium like .080 thickness and above I'll use a #48 drill bit. For thin stock under .080 I'll use a #50 drill bit which is slightly smaller in diameter. Doing this has seemed to greatly increase the life of the taps I use. If you are threading by hand you can also increase the life of your taps by only going in half way through one side of thicker stock metal materials and then back out the tap, flip the piece you are threading over and go through again with the tap on the opposite side the full length to finish taking the threads to where they need to be for easy placement of screws.
Once the taps are dull you can also cheat by doing something like this. Lets say you have a 1/8" thick piece of titanium and you need to thread it for a pocket clip. Ok, drill your number 48 holes after marking them. Then once they are drilled out, replace the #48 with a #44 drill and go down about 1/3 of the way into the holes you just drilled for the 48 size to enlarge them on the outside of the scale. This will enable you to have a larger than needed hole that will act as a hold for the screws not only making it easier to place them since they will fall down in a little when mounting your clip but it will enable you to only have to thread 2/3rds of the total thickness of the scale.
STR
Don't ask me how many times I've threaded knives for clips or made new knives needing threads. I haven't counted but my shop is not at a stand still for sure. I've used that threader in everything from brass to aluminum, titanium and other materials like micarta, G10 and G11 and more. I've lost count.
I will say how long the taps last depends on the proper drill size you use. For example with the 2-56 size screws on really thick titanium like .080 thickness and above I'll use a #48 drill bit. For thin stock under .080 I'll use a #50 drill bit which is slightly smaller in diameter. Doing this has seemed to greatly increase the life of the taps I use. If you are threading by hand you can also increase the life of your taps by only going in half way through one side of thicker stock metal materials and then back out the tap, flip the piece you are threading over and go through again with the tap on the opposite side the full length to finish taking the threads to where they need to be for easy placement of screws.
Once the taps are dull you can also cheat by doing something like this. Lets say you have a 1/8" thick piece of titanium and you need to thread it for a pocket clip. Ok, drill your number 48 holes after marking them. Then once they are drilled out, replace the #48 with a #44 drill and go down about 1/3 of the way into the holes you just drilled for the 48 size to enlarge them on the outside of the scale. This will enable you to have a larger than needed hole that will act as a hold for the screws not only making it easier to place them since they will fall down in a little when mounting your clip but it will enable you to only have to thread 2/3rds of the total thickness of the scale.
STR
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If you do as STR says with the tapping from both sides, may I make a suggestion?
I suggest the 1st side you tap be the far side of the hole.
The odds are greater that the threads will be cross threaded than they are that they will line up.
It would be blind luck to have them line up actually.
Once you start that tap in one side, the exit point on the other is determined.
It's not there yet, but it's location is determined. It can only be in one place, and be right.
Think about it, if we only care to be within 10 degrees of accuracy, we'll still only hit it one in 36 times, if 1 degree, then one in every 360 tries.
At least if you do the far side 1st, you'll have good threads where the screw enters the material.
I suggest the 1st side you tap be the far side of the hole.
The odds are greater that the threads will be cross threaded than they are that they will line up.
It would be blind luck to have them line up actually.
Once you start that tap in one side, the exit point on the other is determined.
It's not there yet, but it's location is determined. It can only be in one place, and be right.
Think about it, if we only care to be within 10 degrees of accuracy, we'll still only hit it one in 36 times, if 1 degree, then one in every 360 tries.
At least if you do the far side 1st, you'll have good threads where the screw enters the material.
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I've never once had that happen doing it by hand my friend. Well, I should say I've never noticed any cross threading going on. Perhaps I am taking them in a bit more than half way though on the first side unconsciously. I always felt it and could see when the tap was off or angled starting out. If it goes straight in on one side and straight in on the other it seems to me the threads should hit straight on. I've never seen a screw hole strip or a screw not hold so I would say they work. I can see that happening without knowing it using a tap matic though because doing it that way takes away the tactile feel and my idea is a lot of feeling it through but again it seems if the work piece is flat, and the drill press is hitting it straight on it would thread the same way on either side right?? For that matter I doubt anyone would need to flip the piece using a tap matic since it happens so fast its not really an issue to mess with.
Anyway, I've not had issues with doing that.
Andy, I am not sure of your stainless and if it is hard or unhardened stock but on stainless, I rarely thread stainless and when I do its always before hardening. I usually just pass on folks trying to get me to thread hardened stainless liners, and especially thicker ones but I have done some thin ones when they twisted my arms. I always warn them since its too risky and most of the work I do is on their carry knives. I don't take risks like that on anything but my own stuff usually.
On thicker stainless I've done some where I just cut off a barrel already threaded and tacked that in a hole on the underside of the handle and threaded into that for people that send me a knife or something like that wanting me to flip a pocket clip to left hand carry or some such thing. Sometimes if there is a 1/8" G10 or other material handle scale you can insert one of these threaded inserts that way also on the underside of the scale where it can sit between the scale and the liner. These are just my own little 'cheats' for lack of a better word to get around having to risk breaking a tap off in someone elses knife and making a mess. Threading hardened stainless is something I rarely tackle.
STR
Anyway, I've not had issues with doing that.
Andy, I am not sure of your stainless and if it is hard or unhardened stock but on stainless, I rarely thread stainless and when I do its always before hardening. I usually just pass on folks trying to get me to thread hardened stainless liners, and especially thicker ones but I have done some thin ones when they twisted my arms. I always warn them since its too risky and most of the work I do is on their carry knives. I don't take risks like that on anything but my own stuff usually.
On thicker stainless I've done some where I just cut off a barrel already threaded and tacked that in a hole on the underside of the handle and threaded into that for people that send me a knife or something like that wanting me to flip a pocket clip to left hand carry or some such thing. Sometimes if there is a 1/8" G10 or other material handle scale you can insert one of these threaded inserts that way also on the underside of the scale where it can sit between the scale and the liner. These are just my own little 'cheats' for lack of a better word to get around having to risk breaking a tap off in someone elses knife and making a mess. Threading hardened stainless is something I rarely tackle.
STR
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Nope.
I wasn't referring to the straighness, or perpendicularity of the threads, but the rotational timing.
Picture it like this.
When you tap halfway through a piece, lets assume the leading point of the thread you have tapped is at the 12 o'clock position, halfway through the workpiece.
Now you flip the piece, and tap again, there is no way to assure the leading edge of the tap meets the already cut point at that 12 o'clock position, assuring one clean thread all the way through.
Make more sense?
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Ok now I follow you. It makes sense. Definitely something to think about and will give me hesitation to do it that way when they dull on me in the future. Ever since I switched to HSS taps I've had a lot less breaks than ever before and far less need to do that but in the old days with carbon taps I did have to do that on occasion when I'd be like down to my last tap on a late Saturday afternoon with more threading to do.
I am puzzled as to why the threading of the screws even worked so smoothly without snags though because I know I have done that a handful of times without seeing any problems or ever noticing having them strip but I guess it just cut new threads the whole way out which kind of makes you stand in awe of the shear toughness of titanium from a new stand point.
Thanks. Learn something new everyday. :thumbup:
STR
I am puzzled as to why the threading of the screws even worked so smoothly without snags though because I know I have done that a handful of times without seeing any problems or ever noticing having them strip but I guess it just cut new threads the whole way out which kind of makes you stand in awe of the shear toughness of titanium from a new stand point.
Thanks. Learn something new everyday. :thumbup:
STR
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I had to play and see this for myself because being a plumbers helper in my youth and early adulthood I threaded a lot of pipe and never hesitated to thread anything else after that. So I went out and threaded some brass rod to see how the timing would end up flipping the rod to thread just some 6-32 male threads on a scrap of brass rod.
I can't explain it. I was hoping to because I wanted to figure out at least in my own mind why my screws never gave me any stick points or rough areas on the ones I did this way. So, I'd thread the small 2" rod I cut off and stop in the middle and flip it around to thread the other side. I did this like five times Bryan and each time when the threads met in the middle you can't tell where one ended and the met it and even under my glass it looks like one contiunous thread down the rod. When I threaded it into a barrel I don't feel it sticking in the middle anywhere and it goes clean through. Actually I used a barrel for a pivot to screw the end I threaded into all the way down to seat it or bottom it out rather and then viced the barrel to hold the rod. Then I took a different barrel that was the type for a screw on each end and threaded the rods I did through it to feel it.
So that explains what has happened in my flipping pieces as far as the ease but I'm not clear on how the threader cleans it up to look that way unless the thread is microscopically thinner or something so slight you can't see it.
Any ideas?
STR
I can't explain it. I was hoping to because I wanted to figure out at least in my own mind why my screws never gave me any stick points or rough areas on the ones I did this way. So, I'd thread the small 2" rod I cut off and stop in the middle and flip it around to thread the other side. I did this like five times Bryan and each time when the threads met in the middle you can't tell where one ended and the met it and even under my glass it looks like one contiunous thread down the rod. When I threaded it into a barrel I don't feel it sticking in the middle anywhere and it goes clean through. Actually I used a barrel for a pivot to screw the end I threaded into all the way down to seat it or bottom it out rather and then viced the barrel to hold the rod. Then I took a different barrel that was the type for a screw on each end and threaded the rods I did through it to feel it.
So that explains what has happened in my flipping pieces as far as the ease but I'm not clear on how the threader cleans it up to look that way unless the thread is microscopically thinner or something so slight you can't see it.
Any ideas?
STR
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Sorry but I am trying to understand this point. When you thread from side halfway, tightening a screw on that side is clockwise, when you start threading from the other opposite side,you also tighten it clockwise. You see, they are being turned opposite each other. Maybe that would explain why they are always in sequence and never cross when they meet and become like one whole thread. I hope you understand what I am saying.
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Yeah but they match up in the middle and the right side is ahead going in on either side since the thread goes right.
My thoughts are so what? I mean we as makers typically drill a hole for a 1/8" pivot of .125 with a number 30 drill recommened in many of the charts that drills a hole .1285 in diameter. Even if these threads do overlap by a fraction of a micron its so small as to be less significant than can even be noticed by anyone from either use or looks from what I'm seeing and feeling. I believe Bryan's point don't get me wrong. I just don't see how it can really affect the end result negatively from looking at it with the threads on the outside so I can see them. Now I may feel entirely different if I were trying this with 1.25" galvanized pipe which is coming if I have my way. I figure it will help my tired eyes.
Its a good point Bryan I'm just trying to figure it out and thinking out loud here.
STR
My thoughts are so what? I mean we as makers typically drill a hole for a 1/8" pivot of .125 with a number 30 drill recommened in many of the charts that drills a hole .1285 in diameter. Even if these threads do overlap by a fraction of a micron its so small as to be less significant than can even be noticed by anyone from either use or looks from what I'm seeing and feeling. I believe Bryan's point don't get me wrong. I just don't see how it can really affect the end result negatively from looking at it with the threads on the outside so I can see them. Now I may feel entirely different if I were trying this with 1.25" galvanized pipe which is coming if I have my way. I figure it will help my tired eyes.
Its a good point Bryan I'm just trying to figure it out and thinking out loud here.
STR
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Not the results I expected Steve. Strange.
Unless you ran the die all the way out on the 2nd pass, making 1 continuous thread...
That's what you do when you tap that way, and it becomes easier because you have already removed material on the farside of the hole.
When you tap, it's could be easier the 2nd time because you actually did line up the threads, or because it's taking less of a cut because you were close, or it even could be pushing the previous thread over, giving the appearance of a normal thread although it might actually be weaker.
I dunno, I'd still do the farside of the hole 1st though.
My turn to experiment.
Unless you ran the die all the way out on the 2nd pass, making 1 continuous thread...
That's what you do when you tap that way, and it becomes easier because you have already removed material on the farside of the hole.
When you tap, it's could be easier the 2nd time because you actually did line up the threads, or because it's taking less of a cut because you were close, or it even could be pushing the previous thread over, giving the appearance of a normal thread although it might actually be weaker.
I dunno, I'd still do the farside of the hole 1st though.
My turn to experiment.