Tapping/threading a drillhole (prolly offtopic)

[UWSDWF]

Slow and low..... if its a soft metal too fast will tear it apart. hard metal will heat and expand

[p1ckf1sh]

On a side note, my project is killing me right now. I thought getting proper taps was tricky, but it wasn't. But now I have other problems, like getting getting a properly straight 2mm slot into a 10mm screw. Currently I am green with envy to anyone with proper machines and tools. I'd kill to be locked up in a machineshop overnight.

But I will tackle it sooner or later, I guess. Or die trying.

[bembel]

Yes, low rpm. And steady.
I found that I can hold the machine with much less sidewards movements than manual cutters (which mostly leads to break the tap). But try it first on something else before ruining you work (and blaming me).

Professionals are doing threads with bench drills anyway.

[UWSDWF]

i'm at work right now with a machine shop MUHAHAHAHA and I was using a proper Tap not 2hours ago

[Shrub]

Professionals are doing threads with bench drills anyway.

Emm sorry i disagree, pros like myself may use a tapping attackment but i would never chuck a tap, hand is best but if your luck to get away with a pistol drill then fine but expect to replce the taps regulary in my opinion but what works for you works so its all good, like it was said make sure the trefolux is on tap or thin oil,

A slot on a bolt eh? well file a slight flat on the thread, centre dot the start of the slot and the end, drill at 2mm then with an abrah (sorry about the spelling, its a round metal work saw blade) cut the slot then finish it off with a needle file.

[bembel]

Emm sorry i disagree, pros like myself may use a tapping attackment

Don't know what this is but we probably mean the same thing (some kind of automatic thread cutter attachment)

but i would never chuck a tap

I was most sceptic, too. Until I tried it.
Learned this on construction sites where time is money. Lifetime of the taps is the same as with any other cutting tools.
However, this was meant as a tip... if the manual thing with 3 taps works best for you, I won't convince you otherwise.

[bembel]

P.S. Did Romstar really quit because of illness?
Seems that I missed something.

[Shrub]

Yes its an auto tapper,

The reason i say no to pistol drills as tapping is that on picks its likely to be small threads, those taps will over heat on an electric drive and wear out, also there is the problem of keeping it perfectly straight or else you snap the tap, the same goes for pillar drills,

The main issue is that in a drill you get no feedback, you need to wind in and wind out all the time which with a drill you are tempted to just wind in, this does blunt the taps a lot quicker than useing them as intended and also can give a poor finish,

Power taps are made differantly, they are on a helix so the material is cut away and cleared more efficently.

I admit it is a way to chuck them but not a reccomended one in my opinon as you say though what works works.

Rom had some myther on here with the delivery of some stuff he sold in the sale section which i think upset him a bit as he is a good bloke, he then hit financial trouble and went through some tough times with having to cancel his connection being one of the out comes, then he hit il health i think to all the stress etc, i believe hes getting well and back on his feet now but i dont know if anyone has contact with him anymore,

The above is what ive summised from the various threads on him in the past, i could be wrong on any or all of it, i didnt really talk to him a lot on pm or email but when i did he seemed a great bloke and knows/knew his stuff.

[bembel]

Sorry to hear that. Thanks for the info.

[mh]

One more question on the 'power'-tapping:

When I learned how to tap, I was told to always turn the tap backwards in between, so that the material that was cut would break into small pieces and would not clutter the tap.

But how does that work on the 'power'-tapping?
Would the motor turn back and forth all the time? Or are there special tap bits that don't require that anyway?

Thanks,
mh

[Shrub]

Well on proper power tapping you use an attachment, this is geared, it not only slows the speed down on some but when pressure is removed from the attachment (let off the machine handle) then the gearing snaps back to another change gear and the tap reverses.

There are special power taps but right now i am not near enough to mine to get one and take a picture of it for you but basically imagine a normal tap but the flues are on a helix, the tap looks like a cross between a drill and a tap.

[Shrub]

Oh and they are cut with differant clearances so they feel very sharp as well.

[mh]

There are special power taps but right now i am not near enough to mine to get one and take a picture of it for you but basically imagine a normal tap but the flues are on a helix, the tap looks like a cross between a drill and a tap.

Thanks, from that I can imagine how they look.
I'd imagine that they could use for manual tapping, too, right?
Next time I buy one, I will look around for them.

Thanks,
mh

[Shrub]

Well i think that power taps only come in plugs so you may need a set of normal ones for hand tapping anyway,

The clearances are made so that they are driven into the work quite quickly and then wound out hand tapping them tends to blunt them im afraid but yes they will work for both,

Ill try my best to remember to grab one and take a pic of it next to a normal one, i have only used them from around 10 mm upwards so they may not be available in smaller dias but im sure they do for smaller cnc machines.

[Shrub]

Imagine a slot drill with teethe on the cutting edge.