kartracer55
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- Jun 21, 2005
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Maybe this is sticky worthy?
It seems like there is a lot of confusion amongst people concerning the different styles of taps and dies, hopefully I can clear all that up in this little post.
Lets start off with taps shall we?(but not before posting your info on THE MAP )
Types of taps-
There are 2 different types of taps, Thread forming and thread cutting. Thread forming taps are almost like bolts, They are threaded all the way around, and you "screw" the tap into a hole, and it forms its own threads. These are rare, mainly being used for plastics and very soft aluminums and brass's. The more common types are Thread cutting taps. They Have flutes, and cut into the material, frming chips. I dont own any of these because for what I do, they dont make sense. Cut threads are fine for me.
There are pretty much 3 main styles of thread cutting taps...
Taper, Plug, and bottoming. A taper tap has about 6 tapered threads on the bottom. These are generally used for starting holes. A plug tap has 3-4 tapered threads. These can be used for Starting holes as well, and are the most common. Generally, tap "sets" will provide you with plug taps. Last, but certainly not least, are bottoming taps. Bottoming taps only have 1 or 2 tapered threads. While these taps cannot start a hole, they are used to cut threads all the way down to the bottom of a blind hole.
There are also varients of these taps. They are called Gun taps (aka Spiral POINT taps) and Sprial Flute taps. A gun tap is a tap that has, as the name implies, a spiral point. These are used only for through holes. With a normal tap, you usually twist the tap around once, and back it out a half turn to break up the chips. A Spiral point tap eliminates the need to twist backwards, by ejecting the chips out of the front of the tap. Gun taps, are usually used with tapping guns, or drills, although a decent amount of skill is required for tapping holes with a drill, therefore it is usually not suggested. A Spiral flute tap does just the opposite of a spiral point tap. Instead of ejecting the chips ahead, a spiral flute tap has flutes like a drill bit, which pull chips back out of the hole. These kinds of taps are usually used for making very deep blind holes. Spiral flute taps are usually bottoming style, whereas gun taps might have 6 or more tapered threads.
Are we having fun yet?
Moving on to Dies...
there are 2 types of dies, Split and solid. The most commong dies you will find are solid dies. these are good for most general use. A split die is intended for when your making very extensive cuts, especially in hard materials (cold rolled and stainless), and when you need to replicate threads with a decent amount of accuracy. A Split die is a die, usually round, which is cut on one end, and there is a little setscrew threaded in between the split. As you tighten this set screw, the die expands. loosen it, the clamping from the die stock closes the gap. Split dies are the correct dies to use if you were to cut your own threads in a pice of round stock. What youw ould do is screw in the set screw all the way to expand the die as much as possible. You would then procede to make the cut all the way along the rod. Next, you would remove the die, then unscrew the setscrew a bit, and secure it in a die stock. By unscrewing the screw, you are allowing the die stock to close the die more, which will in turn cut deeper threads. You would then recut the threads you just cut, making them deeper. You would repeat this once or twice more, unscrewing the screw each time, or takign it out completely. The other use for these is to adjut the screw so that the die fits existing threads tightly, the continue these threads.
Dies are usually either round or hexagonal. All Adjustable dies(except for 2 piece pipe dies) are round.
Taps and Dies are generally sold in two materials, high carbon steel and High speed steel (hss). high carbon steel is inferior to HSS. It will work fine for a weekend warrior, but wont stay sharp for nearly as long as highspeed steel. HSS is usually more expensive that HCS. Coatings on taps and dies are usually not necessarry, other than when a machine is cutting/tapping.
ALWAYS ALWAYS ALWAYS remember to use cutting oil, and at the very east motor oil when cutting threads, to keep your taps and dies sharp, and to get good clean threads.
And so concludes Jims rant... Ill be posting a few more threads of this nature as well. Hopefully, they are sticky worthy.
Jim
It seems like there is a lot of confusion amongst people concerning the different styles of taps and dies, hopefully I can clear all that up in this little post.
Lets start off with taps shall we?(but not before posting your info on THE MAP )
Types of taps-
There are 2 different types of taps, Thread forming and thread cutting. Thread forming taps are almost like bolts, They are threaded all the way around, and you "screw" the tap into a hole, and it forms its own threads. These are rare, mainly being used for plastics and very soft aluminums and brass's. The more common types are Thread cutting taps. They Have flutes, and cut into the material, frming chips. I dont own any of these because for what I do, they dont make sense. Cut threads are fine for me.
There are pretty much 3 main styles of thread cutting taps...
Taper, Plug, and bottoming. A taper tap has about 6 tapered threads on the bottom. These are generally used for starting holes. A plug tap has 3-4 tapered threads. These can be used for Starting holes as well, and are the most common. Generally, tap "sets" will provide you with plug taps. Last, but certainly not least, are bottoming taps. Bottoming taps only have 1 or 2 tapered threads. While these taps cannot start a hole, they are used to cut threads all the way down to the bottom of a blind hole.
There are also varients of these taps. They are called Gun taps (aka Spiral POINT taps) and Sprial Flute taps. A gun tap is a tap that has, as the name implies, a spiral point. These are used only for through holes. With a normal tap, you usually twist the tap around once, and back it out a half turn to break up the chips. A Spiral point tap eliminates the need to twist backwards, by ejecting the chips out of the front of the tap. Gun taps, are usually used with tapping guns, or drills, although a decent amount of skill is required for tapping holes with a drill, therefore it is usually not suggested. A Spiral flute tap does just the opposite of a spiral point tap. Instead of ejecting the chips ahead, a spiral flute tap has flutes like a drill bit, which pull chips back out of the hole. These kinds of taps are usually used for making very deep blind holes. Spiral flute taps are usually bottoming style, whereas gun taps might have 6 or more tapered threads.
Are we having fun yet?
Moving on to Dies...
there are 2 types of dies, Split and solid. The most commong dies you will find are solid dies. these are good for most general use. A split die is intended for when your making very extensive cuts, especially in hard materials (cold rolled and stainless), and when you need to replicate threads with a decent amount of accuracy. A Split die is a die, usually round, which is cut on one end, and there is a little setscrew threaded in between the split. As you tighten this set screw, the die expands. loosen it, the clamping from the die stock closes the gap. Split dies are the correct dies to use if you were to cut your own threads in a pice of round stock. What youw ould do is screw in the set screw all the way to expand the die as much as possible. You would then procede to make the cut all the way along the rod. Next, you would remove the die, then unscrew the setscrew a bit, and secure it in a die stock. By unscrewing the screw, you are allowing the die stock to close the die more, which will in turn cut deeper threads. You would then recut the threads you just cut, making them deeper. You would repeat this once or twice more, unscrewing the screw each time, or takign it out completely. The other use for these is to adjut the screw so that the die fits existing threads tightly, the continue these threads.
Dies are usually either round or hexagonal. All Adjustable dies(except for 2 piece pipe dies) are round.
Taps and Dies are generally sold in two materials, high carbon steel and High speed steel (hss). high carbon steel is inferior to HSS. It will work fine for a weekend warrior, but wont stay sharp for nearly as long as highspeed steel. HSS is usually more expensive that HCS. Coatings on taps and dies are usually not necessarry, other than when a machine is cutting/tapping.
ALWAYS ALWAYS ALWAYS remember to use cutting oil, and at the very east motor oil when cutting threads, to keep your taps and dies sharp, and to get good clean threads.
And so concludes Jims rant... Ill be posting a few more threads of this nature as well. Hopefully, they are sticky worthy.
Jim
