Good source for quality tiny taps/dies?

[Stan]

Dean: I guess I am particularly stupid when it comes to the H numbers. I understand the charts to mean that most taps have the pitch diameter .0005" larger on each successive H number. If the bolt is a tight fit in a H1, is it then a loose fit in an H3?

I know that an H3 takes more torque to thread a hole because it is cutting deeper. Would using a tap drill .001" larger give the same resultant thread? These questions are all simply curiosity because as I said in my previous post I don't think it affects anything I do.

 

[steamer]

A "gun" tap pushes the chip forward, so its free-er cutting than standard taps....but is really intended for through holes in tough materials.....like a gun receiver.

They usually have two flutes.


Dave

 

[shred]

A "gun" tap pushes the chip forward, so its free-er cutting than standard taps....but is really intended for through holes in tough materials.....like a gun receiver.

They usually have two flutes.


Dave

Hmm.. I always thought it was because they "shot" the chips in front (though Enco, et al call them "Spiral Point" as I think somebody has "gun tap" trademarked). Anyway, they work well in softer materials, even in blind holes if you can drill a little extra deep to have room for chips. They don't load up the flutes so there's less of the one-step-forward-two-steps-back routine.

In larger sizes 1/4" and up, I've had ok luck with decent HSS imports.

 

[websterz]

http://www.micromark.com/SearchResult.aspx?deptIdFilter=0&searchPhrase=taps

 

[Deanofid]

Dean: I guess I am particularly stupid when it comes to the H numbers. I understand the charts to mean that most taps have the pitch diameter .0005" larger on each successive H number. If the bolt is a tight fit in a H1, is it then a loose fit in an H3?

Hi Stan;
It's not stupid. It's a mixed up thing we're talking about, because we get the idea that one might be better than the other. When taps are identified for a print, they get the "h" number, but the hole and fasteners themselves do not, as far as I know. They get a different alpha/numeric system to themselves.

First, I guess we have to say that "tight" and "loose" are relative terms. I'll just say yes, you could consider the h3 cut a looser fit than the h1 cut, but I don't want you to think that means it's bad, or sloppy. It's just a tolerance for the tap. It affects the tapped hole only if the print tells you it does.

The size of the tap drill remains the same, so the minor diameter of the hole should be the same, but the outside of the h3 tap is larger where it cuts threads, so it would make sense to say it will be looser. Still, one is not better than the other. It depends on what thread the tap is cutting. If it's cutting for 0-80, then the tolerance of h2 will give the "average" cap screw some breathing room. If you're using a tap that cuts 1"-12, then h2 makes that hole a closer fit with that size cap screw, because the percentage of the tolerance decreases in relation to the diameter of the tapped hole.

Don't worry about all this stuff. If what you're doing or using now works for what you are building, then everything is fine.

I know that an H3 takes more torque to thread a hole because it is cutting deeper. Would using a tap drill .001" larger give the same resultant thread? These questions are all simply curiosity because as I said in my previous post I don't think it affects anything I do.

I'm not certain, but it sounds sensible to assume so. There is going to be some geometry affecting it because when the tap diameter increases, the edge of the thread between the top of the thread and it's root (on the tap) changes in length.
I don't even take the "h" number into account when drilling tap holes. Most of what I have here are h2 in the smaller sizes, but a few are h1 and some h3. For any of my taps that are over 1/4", I don't even know the "h" number because most of them are consumer taps, from the hardware store.

Dean

 

[Stan]

The only way this makes sense to me is if fasteners are made to matching standards. If you use the same size of tap drill, an H3 tap will give a greater depth of thread which which presumably is more resistant to pull out. A standard fastener in that hole will be more likely to pull out because it is pulling on the crest of the threads instead of at the root.

I have searched Machinery Handbook on this subject without result but I expect somewhere there is a standard for a male thread to fit the H numbered taps.

Regardless of the H number, I open up the die a little bit if I want a tighter fit on a shop made fastener. I single point the thread until it is a couple of thou oversize and then run an opened up die. Repeated passes with the die closed up a bit get me to a tight fit. I did this on the adjusting screw for my taper attachment.

 

[BigBore]

http://www.microfasteners.com/catalog/products/TNMTAP.cfm[/url]

Thanks for hangin' with me guys!

Ed

I talked with Bill at Micro Fasteners this morning and their taps are indeed imports. This thread is great. I think I have saved the cost of a book. Great info that I had never considered. Thanks.

Ed

 

[BenPeake]

Not much showing from the lads in the UK.

I use these people and have found the quality is second to none. The individual prices do look a little costly, but as soon as you get to bulk prices the costs drop very sharply.

I usually buy in 10's, and pay just over 2 pounds each for taps, and I think the die price breaks start at about 5 off.
They cut stainless as though it is brass, and I power tap on the lathe as small as 3mm with no problems.

http://www.tapdie.com/

They seem to stock every size you will ever need, and they cater mainly for industry. Because of that, I have phoned them late afternoon and they are delivered first thing next morning.


Blogs

Just thought I'd ask you Bogstandard,

I just bought some of these taps and they don't say HSS on the side, they say HQS. Any idea what the difference is? I'm on holidays, so I haven't had a chance to use them yet, but I'm looking forward to giving them a test on stainless. "They cut stainless as though it is brass" - a very enticing proposition. Has anyone else tried these?

Thanks,
Ben Peake