Spiral flute taps

Brad

Benevolent Overlord and site owner
Staff member
I had never owned, much less used, a spiral flute tap until now. I bought a 1/4-28 spiral flute tap for a project I am working on. I grew weary of the twisty turns hand taps and wanted a tap better suited to use with my new hand tapping device for the lathe.
Mind blown!
Drilled a #1 pilot hole an inch deep and went to work with the tap. A little cutting oil and 65 rpm. OMG! It was like I was doing nothing at all. No real torque on the tapping device. Tap just makes a couple long chips coming out of the hole as it keeps going deeper. I did back the tap out once just to look but then drove it to full depth. Might have taken me a minute to tap the hole nice and straight.
I really like this spiral flute tap for a blind hole. How to see how my new spiral point 10-32 tap does on some thru holes.
 

KeithB

Resident Half Fast Machinist
Another convert to using spiral flute taps in blind holes! They do work nice when you can hold them in line properly. And that's a pretty nice hand tapper you built. Good for you Brad!
 

smokeywolf

Well-Known Member
Most efficient taps I've found for blind holes are spiral or helical flute taps for most any material or Express (thread former) taps for plastics, aluminum and brass.
 

KeithB

Resident Half Fast Machinist
Nice video. Really shows clearly the action of a spiral flute tap. And no chips to winkle out of the bottom of the hole. Good job!
 

Ian

Notorious member
Oh yeah! That's what we're talking about, nice video Brad.

We need a "golf clap" smiley.....
 

Pistolero

Well-Known Member
They take noticeably lower torque to thread, too. I have about 6 of them, saved for hard
to do jobs.

Bill