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+--- Forum: General Metalworking Discussion (http://www.metalworkingfun.com/forum-6.html)
+--- Thread: Taps (/thread-885.html)
RE: Taps - DaveH - 12-27-2012
Serial taps - never heard of them.
The taps from Arc Euro Trade seem just like 'Hand taps', for hard materials.Hand taps normally come in 3's.
I tend to use a cutting oil with my hand taps
makes for easier cutting. 
DaveH
RE: Taps - Bill Gruby - 12-27-2012
This is the first I have heard of Serial Taps also Dave. They are used to make a progressive thread cutting. #1 is a rougher followed by #2 an intermediate, followed by #3 the finish cut.
"Billy G"
http://www.carbidenz.co.nz/store/index.php?dispatch=products.view&product_id=1950
RE: Taps - Arbalest - 12-27-2012
From: http://www.practicalmachinist.com/vb/general/serial-taps-home-made-151027/. 4th post.
"Unless used in a very short blind hole, Normal taps essentially set out to cut a full depth thread with every tap, they just move it closer to the blind end with subsequent taps. If you don't have a blind hole, you need only use one tap.
The idea of serial taps is that the volumetric removal of the metal is spread over all three taps evenly, even for thru holes. This makes them excellent for hand tapping of difficult materials, like extreme work-hardening grades (hi-nickel alloys such as Monel, some grades of stainless steel, etc).
The individual taps do not work very hard. I have an SKF set I've owned for thirty years, they've tapped some horrible materials, and they're still every bit as good as new."
Must admit It's a new idea to me, never knew they've been around for so long.
RE: Taps - DaveH - 12-27-2012
Arbalest,
Seems they should work quite well, taking a bit off with each tap, but you said your were a little disappointed - was it with the 'force' you were using?
Now you are sure you were not on one of your 'weaker' days
DaveH
RE: Taps - Arbalest - 12-27-2012
I was just as concerned about tap alignment Dave although I must admit I expected each tap to remove a similar amount of material and therefore require about the same amount of effort, which was'nt the case. I should add that I use Tamaxol cutting compound when thread cutting in steel. I also have M6 so I'll give those a try when I get a minute. I must admit that the quality of the resultant thread seems very good in terms of finish (smoothness) but I can't prove this.
RE: Taps - DaveH - 12-27-2012
(12-27-2012, 07:41 PM)Arbalest Wrote: I also have M6 so I'll give those a try when I get a minute.I would like to know what you think.
DaveH