DEEP TAPPING - HOW TO ?

[morrisman]

hi

I am getting back to my dividing head project . Harold Hall

I need to tap two deep holes in the main body - the tapped section of the holes begin about 1 3/4" down at the bottom of the drilled holes , they are blind holes . He just writes "drill and tap holes A & B"
so how does one tap such deep holes ? mike

[Stustoys]

Hi Mike,

Well you could buy a long series tap... but I guess that isnt a lot of help.
Which book are you using?

Stuart

[.RC.]

Find a socket that will fit the square on the tap.... add an extension and away you go....

May have to turn the socket down, so buy a cheap one for that ;)

I have done the above a few times...

[RayG]

Hi Mike,

What size holes? If the hole is large enough, use .RC.'s method, if you are talking smaller diameters, you can always braze a piece of rod onto the tap.

Ray

[morrisman]

Hi Mike,

What size holes? If the hole is large enough, use .RC.'s method, if you are talking smaller diameters, you can always braze a piece of rod onto the tap.

Ray



THANKS

THE HOLES ARE only small , about 6mm diam. I think .

Stuart . it is the milling machine book with the orange ? cover

Yes brazing an extension would be ideal but I dont have the torch yet ..its on its way apparently but the sailing ships from the UK are not having good conditions this year..mike

[Stustoys]

Hi Mike,
I can't see your problem...
I make the holes total depth about 54mm, 29mm of that 6.5mm clearance. My M6 taps are 6.25ishmm diameter on the shank, 58mm from tip to the square shank.

Am I missing something?
Or do you have short or fat taps?(if so PM me your address)

Stuart

[morrisman]

Hi Mike,
I can't see your problem...
I make the holes total depth about 54mm, 29mm of that 6.5mm clearance. My M6 taps are 6.25ishmm diameter on the shank, 58mm from tip to the square shank.

Am I missing something?
Or do you have short or fat taps?(if so PM me your address)

Stuart

Hi Stuart

My ALDI 6mm tapered tap is about 10 mm shorter than your tap is .

I will have to go into BJ Bearings and buy the correct plug tap for the job , hopefully it will be long enough to do the job

Regards and thanks ......... Mike

[cba_melbourne]

Hi Stuart

My ALDI 6mm tapered tap is about 10 mm shorter than your tap is .

I will have to go into BJ Bearings and buy the correct plug tap for the job , hopefully it will be long enough to do the job

Regards and thanks ......... Mike

Get a spiral flute tap for this job. Spiral flutes eject the chips to the rear and out of the blind hole. If you use straight or spiral point taps, you have to drill the hole deeper or/and retract the tap several times to clean out the chips wedged deep down in in the blind hole with a small spiral drill or the like. If I could only have one single tap in a given size, I would make it a spiral flute tap - it is the most versatile type of tap. Spiral flute taps are also usually of better quality then straight flute taps. Chris