Holding taps in a drill press

[pgrbffParticipant @pgrbff]

I have done little tapping but when I do I use my small drill press if possible to make sure the tap is perpendicular to the workpiece.
With a square end is the tap actually central in the chuck which has 3 jaws?
What can I use to hold the taps before inserting them in the chuck?

Edited By pgrbff on 03/04/2022 07:43:23

[pgrbffParticipant @pgrbff]

[JasonBModerator @jasonb]

Hold by the round shank not the square on the end. Also look at last weeks thread tapping straight for many suggestions that apply to guiding the tap

Edited By JasonB on 03/04/2022 07:57:31

[Paul LousickParticipant @paullousick59116]

These are a couple of Youtube videos with different methods of keeping the tap straight. (although a bit long winded at times)

**LINK**

**LINK**

[pgrbffParticipant @pgrbff]

Thank you both. I have always used the drill press so tapped holes are perpendicular.

Can't believe I didn't think of pushing the tap further into the chuck!

[egaParticipant @ega]

Commercial tapping chucks typically have a collet to hold the tap shank true and a "two jaw chuck" to grip the square and provide the drive

Edited By ega on 03/04/2022 09:51:16

[pgrbffParticipant @pgrbff]

I assume the lines, one line, two lines or no line tell us which tap is which?

What is the convention?

Edited By pgrbff on 03/04/2022 09:53:10

[Ady1Participant @ady1]

Posted by pgrbff on 03/04/2022 09:07:35:

Thank you both. I have always used the drill press so tapped holes are perpendicular.

Can't believe I didn't think of pushing the tap further into the chuck!

Made my morning that, nice to know I am not alone

I would like to welcome you to the best forum on the net for growing old and daft in good company

[David-Clark 1Participant @david-clark1]

Many taps have male centres so a bit of bar with a female centre in it will support it true, Also eclipse Tee type tap wrenches have female centres so can be supported by male centres, Finally, a bit of tube that slips over the end of the tap shank can be used. For smaller taps, use a knurled sleeve grub screwed to the tap shank.

[JasonBModerator @jasonb]

Those three taps in your photo are "serial taps" you have to put the single groove through first, then the two groove and finally the plain shank to get a fully formed thread. see here

Edited By JasonB on 03/04/2022 10:05:58

[pgrbffParticipant @pgrbff]

Posted by JasonB on 03/04/2022 10:04:11:

Those three taps in your photo are "serial taps" you have to put the single groove through first, then the two groove and finally the plain shank to get a fully formed thread. see here

Edited By JasonB on 03/04/2022 10:05:58

Thank you. I was tapping a thin piece of ebony, 6mm, and went straight for the no groove.

Edited By pgrbff on 03/04/2022 10:12:05

[Clive FosterParticipant @clivefoster55965]

+1 for serial taps.

Considerable reduction in tapping force which makes life much less fraught with small taps. Especially on difficult materials.

Yesterday I used my M4 serial set when making some 6 mm long threaded inserts to glue into thick glass fibre panels without decent rear access for proper headed inserts. M6 stainless steel stubs tapped M4. Done on the S&B 1024 lathe by holding the tap in a chuck in the tailstock with the stub gripped a collet in the spindle. Lathe in neutral. Spindle turned by hand using the collet handwheel. Bit of push in on the tailstock to engage the tap.

Easy to feel the difference between ordinary hand tap, spiral form machine tap and serial ones. As the collet was gripping on a short thread holding force wasn't wonderful but both ordinary taps and the machine tap would turn the stub when well into the thread. Accompanied by "cracking" feel. Not good for the nerves. Plenty of trefolux tapping lube applied of coarse. Fairly hefty lathe so plenty of metal turning round with a good deal of inertia to watch out for.

These days I buy serial or machine taps if I have the choice.

One issue to bear in mind when tapping in a drill chuck is the drag and inertia of the spindle, belt and motor. Which interferes with feel, dangerously so on small taps. Best to drop the belt or at least put it on top speed so the motor is effectively geared down relative to the spindle reducing its contribution to the load.

When using smaller taps there is much to be said in favour of the sliding tap holder on a spigot devices with a knurled wheel to turn by hand. No load from the drill spindle so far easier to feel what's happening so you can stop and reverse before the tap breaks. Something I should have made many years ago but no longer need as I have alternatives.

Clive

Edited By Clive Foster on 03/04/2022 10:40:21

[Howard LewisParticipant @howardlewis46836]

Tapping in the mill, I usually use a spring loaded tap guide in the drill chuck. This holds the Tap in line with the drilling, and the point and centre (can be either way round depending on the size of Tap ) to keppe the Tap in line.

Actually, think that the gadgets that I have are called either "Tap Tru" or "Tap In Line".

The advantages are

The tap is held in line with the drilling, and perpendicular to the work

Th Tap , although driven by a tap Wrench" is not subjected to the bending moment likely to break it in the work, (Usually in the last hole! )

HTH

Howard

[Ramon WilsonParticipant @ramonwilson3]

Tapping as such Howard is only possible if the hole is fixed directly under the spindle – that won't work successfully if it's not.

I offer the following for anyone with limited kit which works both ways

Make brass 'tubes' to suit the tap shank – be aware that some tap shank sizes are not standard imp or metric dimensions. If so make a tube over size as close as possible then slit it so the chuck can close it slightly so the tap is a firm but loose fit in the tube.

Grind a small flat on the shank of the tap just above the threaded portion – I do this on the corner of the grinding wheel – just wide enough to take a tap wrench – the thinner the wrench the better.

With the drilled hole positioned beneath bring the tap to the hole by sliding down the tube and engage the thread. Here's an image that shows what I mean – the cylinder blocks in question had well over a hundred 8 and 7 BA holes in each, both blocks floating on the table – the angle plate and magnet acting purely as stops to prevent rotation

The brass bush is readily seen in this view

 

I've used this method from 16BA to 3/8 ME + and find it a very good method to get squareness and fine control over the process. The right size wrench is important – this little Eclipse is no longer available but is ideal up to 2 BA. An ideal wrench for the smaller sizes can be made from a 1" disc of mild steel, knurled on the outer diameter, the tap gripped by a cross screw.

Another method I use just as frequently but on the drill press is to lightly grip the tap directly in the drill chuck, Making sure the depth stop is not set, the drill is in lowest speed and turned on then off. As the spindle powers down the tap is brought into the hole via the quill and will tap several threads before stopping, Release chuck and tap the remainder of the hole by hand. Care is needed but mainly to ensure the tap does not bottom out.

Perhaps I should say that I do have a Tapmatic tapping attachment but can't even remember the last time I bothered to set it up.

All of the above has been done over many years and served me well and yes, all directly as a result of the same problems experienced by 'pgrbff'

 

Hope that's of use pg

 

Tug

Edited By Ramon Wilson on 03/04/2022 20:32:12

[peak4Participant @peak4]

In with my tapping stuff, I gave a few round metal bars.
Each has a taper on one end, and a centre drilling on the other.
If I've drilled the hole to be tapped on the bench drill, I just clamp the workpiece down, then put one of the bars in the drill chuck.
The tap goes in a conventional holder, but the top end is located, either by the taper, or the centre drilling, depending on the tap design.
I normally just apply pressure with my right hand on the drill press lever, and turn the tap one handed, or may use a weight on the drill handle; even a bungee cord on the lever will apply suitable pressure to keep the tap in-line.
If I haven't drilled the hole on the machine, or there's lots of holes, the pointy end of the bar will locate the workpiece, and proceed as before.

Bill

[HuubParticipant @huub]

From rigth to left, some taps I use for the mill and the lathe

For the mill, and the lathe I use taps that have a hex shaft and a drilling point
For blind holes, i grinded off the drill portion of this tap
To hold common taps I mount (shrink fit) an aluminium 3 flats holder.
You can also use hex steel to shrink fit but the then the difference in diameter should be around 0.02 mm
The last tap is used for manual tapping using a DIY tap holder. The mill or lathe tail stock are used for guiding the tap. The round bus is used to centre, the square end for clamping. I use this is only for larger taps when the torque of the mill or lathe is to low.

[Ramon WilsonParticipant @ramonwilson3]

Hi again PG

Have just found these mages that may be of further use to you …..

I think this is 10BA – the disc is about 19mm dia

It gives plenty of torque without stressing the tap – plenty of 'feel'

And this time 12 BA on the lathe

Cheers – Tug

[Bill PhinnParticipant @billphinn90025]

Posted by pgrbff on 03/04/2022 09:51:14:

I assume the lines, one line, two lines or no line tell us which tap is which?

What is the convention?

Edited By pgrbff on 03/04/2022 09:53:10

Whilst those in your image are certainly serial taps, the same markings can sometimes be found on a standard set of hand taps, as below on this set of M3 coarse.

[pgrbffParticipant @pgrbff]

Thank you all. Lots of useful info. Paul

[Author]

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