Taps, what is your choice? (technical question)

[bob243]

Just out of curiousity, does everyone here use just basic hardware store taps or do you generally order something specific for doing drums, touchhole liners, breach plugs?

Probably overthinking this aspect,(which I often do :youcrazy: ) but I figured I would ask. It is worth or necessary to go with a higher class of fit or an H limit other than the common H3 ?

How about materials? (I have about a 50/50 mix of carbide and HSS.

 

[Zonie]

I use the taps that are available at Ace Hardware and no, I don't use the special class taps. I see no reason to use them for several reasons.
First off, the threads in a muzzleloader are not very highly stressed. Even in the drum/vent and breechplug areas.

Second, in order to fully utilize the special classes of threads both the hole and the fastener must be of the same class.
Finding a mild steel class 3 male thread fastener is almost impossible let alone finding a UNJ class 3 thread and using an A286 12 point bolt somehow doesn't look very authentic. :rotf:

For tap material I use the standard HSS taps and have had good luck with them but I'll add that many builders much prefer the High Carbon steel taps.

Their reasoning is that if the tap breaks off in the hole it is fairly easy to shatter the High Carbon steel taps but the HSS or Cobalt HSS taps are almost impossible to shatter without severely damaging the hole.
IMO, that ease of shattering that makes removing a broken High Carbon Steel tap fairly easy also makes that kind of tap fairly easy to break in the first place.

For those new to taps and dies let me say that you must avoid at all costs the inexpensive black taps carried by some of the import houses.
Cheap taps invite breakage and the set my wife bought for me doesn't even tap a hole that is near to being right. They are total garbage so don't waste your money.
Buy a good made in the U.S.A. tap. You will be glad you did.

(Afterthought for those new to making threads:
Always use a "Thread Cutting Oil" when tapping steel. Motor Oil, Transmission Fluid, WD40, and any other kind of oil will not work .
Thread cutting oil has sulfur and other things in it specially designed for making threads. Using any other kind of oil is almost guaranteed to break the tap off in the work.)

 

[bob243]

Thanks for the info :grin: Thanks for pointing out the fact that it does not matter because the threads on the drum, breechplug etc are not going to be a 2a or 3a fit. It is one of those cases where I needed someone else to have a look because I was thinking too hard :redface: :redface:


For lube, I tried some of the newer fancy lubes and honestly I end up going back to Rigid Dark. It is cheap, I have the best luck with it, and you can usually find it at any plumbing supply store. It also works great for cutting fluid on the mill.

 

[Birddog6]

Personally, I like the spiral point 2 flute taps with the shank trimmed down. They seem to cut better for me & less breakage, especially on the bolsters of the lock. And when I make SS range rods, they are a must to tap those SS rods as those buggers are tough & you will snap a tap in a heartbeat. :shake: I stay away from any imported elcheapo taps, those are a recipe for disaster......

 

[paulvallandigham]

The number two reason I see taps broken is that the user turns the tap too fast, and too far, without backing up to break off the chips.

I was taught to go slow, and do 1/4 turn, turn back at least 1/8 turn, then go forward another 1/4 turn( actually cutting only 1/8 turn of new metal) then back again.

Yeah, its slow, but you get nice threads, and the end result looks like a lathe cut the threads using a carbide cutting bit. The best part is that you can make sure that our tap is going into the pre-drilled pilot hole Square. When you are using a hand operated tap, its very easy to get a tap started crooked, and that is why the taps break most of the time.

I agree with Jim that you need to use special Tapping Oil- available at the same hardware store where you buy the taps and dies. I have made due with penetrating oil, but I sweated profusely all through the process! :shocked2: :redface:

 

[ehoff]

Sounds like we had the same teacher. I was also taught to cut a 1/4 turn at a time, back it off, cut again, always use tapping fluid and a spring loaded center in the mill, lathe, drill press, etc.

 

[Stophel]

Actually, I think the number one cause of broken taps is that you're trying to use a dull tap.

I will use HSS taps, if that's all I have, but greatly prefer good quality high carbon steel taps. Generally, I use Hanson taps. I HATE Vermont American taps (and most everything else they produce). Not very sharp, not clean and crisp like they should be.

I just use whatever oil is at hand. Never had a problem in that area. Turn the tap a quarter or half turn, then back it up and blow out the chips.

 

[paulvallandigham]

I had guys in my shop class in high school who broke taps, because they didn't listen. They thought they could set a speed record taping a hole in their project.

You should watch them put their whole upper body into turning the taps as fast and as far as they can turn their wrists. Oil? Why? They would not listen, until they did break the tap, and the instructor read them the riot act, charged them for a new tap, and made them do the labor to remove the broken tap from their work project.

My father had taught me to tap, and use dies to thread rods, long before I took that shop class-- even my instructor noticed that I was not a " rookie " at the work.

I have never broken a tap, although I have seen it done several times, by others, and been present when it was done when I was NOT looking, even more times.

 

[Zonie]

Bob:
I forgot to answer part of your question.

For tapping nipple drums or snail bolsters for nipples I don't bother trying to find a "Bottoming Tap" although that is what is needed.

I just buy an extra tap and, using a pan of water next to the grinder to cool it often and my bench grinder, I grind off the tapered lead area.
I've found that if I grind for a second and cool for 5 it doesn't seem to soften the taps material and it doesn't take long to have a nice bottoming tap.

For those new to tapping, a Bottoming Tap does not have any partial threads at the end. It cuts to the full thread depth with all of its teeth.
This is important when tapping very short holes that need to have threads all the way to the bottom of them.
Because it doesn't have the tapered "starting" area it cannot be used alone. One must first use a standard taper tap to tap as deeply as possible without hitting the bottom. Then remove the standard tap and using finger pressure only, screw the bottoming tap into the partially threaded hole. Then install the tap wrench onto the tap and cut the rest of the threads.
Great care must be used because when the first thread gets to the bottom of the hole any additional turning will instantly break the tap off.

As for Breech plug threads, I haven't had a need to make them.
All of the factory barrels I've bought were already threaded almost to the bottom shoulder where the bore ends.
To keep from having to use a "Bottoming" style tap I choose to just remove the first one or two threads on the breech plug with a flat file.
This allows me to install the breech plug without it hanging up on those partial threads that come in the barrels.

Because of the large size and the need to accuratly align the tap with the hole when cutting a breech thread I wouldn't even attempt to do it by hand. A good lathe to keep things aligned is really the best way to do that job.

 

[Stophel]

I've made many "bottoming taps" from plug or taper taps.

I've broken a few taps. Some from trying to use a dull tap longer than I should have. I've accidentally leaned on one or two and snapped them off (I'm pretty clumsy). I've also broken one or two by not using the proper drill bit for the tap. I didn't happen to have the proper size on hand and used one that was "close"...but not close enough. All things I shouldn't have done.

But, those broken taps are good for turning into bottoming taps.

 

[bob243]

I got brave and tried using my mill to tap some holes I put in a scrap piece. I have a variable speed mill, had the control in one hand and the oil in the other, using one of those spiral fluted taps. It worked out good, not sure if I will try it on a barrel yet, but maybe after some practice.

I also have one of those bench mounted taping tools (looks kind of like a arbor press with a handle on top) I havent figured out where to make room for it yet though.

I don't have a lathe yet, it will require some construction work in my shop before I can get one.

 

[ToddB]

The number two reason I see taps broken is that the user turns the tap too fast, and too far, without backing up to break off the chips.

I was taught to go slow, and do 1/4 turn, turn back at least 1/8 turn, then go forward another 1/4 turn( actually cutting only 1/8 turn of new metal) then back again.

Yeah, its slow, but you get nice threads, and the end result looks like a lathe cut the threads using a carbide cutting bit. The best part is that you can make sure that our tap is going into the pre-drilled pilot hole Square. When you are using a hand operated tap, its very easy to get a tap started crooked, and that is why the taps break most of the time.

I agree with Jim that you need to use special Tapping Oil- available at the same hardware store where you buy the taps and dies. I have made due with penetrating oil, but I sweated profusely all through the process! :shocked2: :redface:

Its not the speed thats breaking the tap its the misaleingment with the hole that breaks it. And spiral flute taps don't need to have the chips broken as they pull the chip up out of the hole.

And be careful with the carbide taps as carbide is brittle. They won't flex like steel will.

 

[paulvallandigham]

I have not had an opportunity buy or use a spiral fluted tap. I am so old they weren't available back when I was learning and all the taps I used, and still have , have straight flutes.

I still prefer to back them out and brush out the chips on a regular basis, and probably would do the same with a spiral fluted tap, too.

I blow air in the tap holes, to get any loose chips out of there, and have been known to use pipe cleaners, or even a toothbrush, when the hole is big enough, to clean out the chips. I use a brush to clean the thread of the tap of chips, too.

Protecting fine cutting tools from abuse, that can only dull them, if not break off teeth, or break the entire tool, should be a major concern for folks. Maybe they have more money to spend on their tools than I do. I don't like to have to hold up completing a project while I find and purchase a replacement tool because I broke the one I had.