spiral point taps

savarin

savarin

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I expect the cognoscenti already know this but I just had to mention it as I was so impressed with the results.
I had to drill and tap 15 x 5mm holes in some hot rolled steel.
Usually I use the standard taper tap to start followed by the intermediate and bottoming tap.
I start the taper tap in the drill press (no power) to start it straight then release the chuck, transfer to the vice and use the tap handle to complete the threading operation.
All 15 holes were straight through so no need for the bottoming tap.

In this instance I used a spiral point tap and am amazed how much easier and faster it was.
I started all the holes by hand, they didnt require much in the way of pressure to start and I swear they pulled themselves straight as soon as they started to cut.
I am so impressed that I will purchase a spiral point in all my most used sizes.
 
Thanks David, after this experience I have to.
 
Good topic, savarin. I have been using a standard taper tap for both blind and through holes. I bought a 1/4” spiral point ‘gun tap’ to try my hand at power tapping some through holes on the mill, but haven’t got a round tuit yet. I need to get off my duff and try it.

David, thanks for the tip on spiral flute taps for blind holes. My education continues.

Tom
 
Once you try spiral flute and spiral point taps you won't go back to regulars taps. No backing off to break the chip, automatic chip ejection, lower effort to cut a thread. I have also noticed I break fewer taps since making the change.

Paul.
 
I"m using 4-40 and 5-40 spiral flute tapping drill rod, both thru and blind holes. I swear I can see the shank twisting as I tap the holes, both in a chuck in my mill and by hand, but I haven't broken one yet. I run the mill about 200 rpm, stop and reverse before the full thread portion of the tap enters the hole.
 
My faves are Guhring spriral point taps in Cobalt bright or TiCn PowerTaps. Excellent taps. All ground.
Prices range depending on class of fit, thread limits, etc... I prefer the 3 flute SP but are more expensive.
Ebay has some good deals on Guhring and Emuge taps.
 
EmilioG said:
My faves are Guhring spriral point taps in Cobalt bright or TiCn PowerTaps. Excellent taps. All ground.
Prices range depending on class of fit, thread limits, etc... I prefer the 3 flute SP but are more expensive.
Ebay has some good deals on Guhring and Emuge taps.
Click to expand...

I do a lot of business with Chinese manufacturers and suppliers. I have been thinking of ordering some of the higher quality, Chinese made taps and dies for testing. They are much cheaper than Ghüring and if they check out then stocking up on them. I use older SKF, Ghüring, Dormer etc. so it would be interesting. I have been pleasantly surprised with other machine tools such as cutting tools and holders in the past so this would be a great experiment to find more cost effective alternatives.

Paul.
 
samthedog said:
I have been pleasantly surprised with other machine tools such as cutting tools and holders in the past so this would be a great experiment to find more cost effective alternatives.
Click to expand...

Paul, if you do, I hope you post the results of this experiment.
After Emilio's post I went and checked ebay for Guhring ones.......out of my budget......especially with shipping to Canada basically doubling the price.

-brino
 
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