thread maker tool

[tjb1]

forgot to mention - the oil don't have to be cutting oil (the one used when machining steel), i'm using silicone oil when cutting threads to aluminium, but any oil would do the job for aluminium (except vegetable oils )

so basically this is all you need:

Those 3 taps are the same tap...the different taps are Taper, Plug and Bottoming.  In softer materials you could really start with the bottoming and use that only as long as you start it straight.  Taper taps just have a much longer lead in to help start the tap parallel to the hole, plug are common as they are a compromise of both.

those 3 taps are definitely NOT THE SAME TAP ! those are for progressive taping - you go with the "single strip first", then "double strip" and then the "no strip" each one is cutting he groove deeper and deeper. - to cut precise thread you have to do it progressively.

Uh no, those stripes identify the tap and you do not have to use all 3 to do a thread.  Single is suppose to be TAPER tap, Double is PLUG tap, None is BOTTOMING.  Really has nothing to do with the thread itself, you will have a hard time aligning a BOTTOMING tap in a plain hole to start it.  That is what the TAPER tap is for, it has a very long taper at the front to allow it to guide itself into the hole.  This TAPER tap is fine for almost all situations, the only time you move to the other taps if you want to cut FULL threads to the bottom of a blind hole.  In fact, TAPER isn't that common since a PLUG can really do the same thing.

Did you buy your taps from China?  Every tap looks exactly the same, the taper on all of them appears the same and the last tap with no stripe on it is certainly not a BOTTOMING tap because it has a point on it.

Look at the picture

[rob77]

forgot to mention - the oil don't have to be cutting oil (the one used when machining steel), i'm using silicone oil when cutting threads to aluminium, but any oil would do the job for aluminium (except vegetable oils )

so basically this is all you need:

Those 3 taps are the same tap...the different taps are Taper, Plug and Bottoming.  In softer materials you could really start with the bottoming and use that only as long as you start it straight.  Taper taps just have a much longer lead in to help start the tap parallel to the hole, plug are common as they are a compromise of both.

those 3 taps are definitely NOT THE SAME TAP ! those are for progressive taping - you go with the "single strip first", then "double strip" and then the "no strip" each one is cutting he groove deeper and deeper. - to cut precise thread you have to do it progressively.

Uh no, those stripes identify the tap and you do not have to use all 3 to do a thread.  Single is suppose to be TAPER tap, Double is PLUG tap, None is BOTTOMING.  Really has nothing to do with the thread itself, you will have a hard time aligning a BOTTOMING tap in a plain hole to start it.  That is what the TAPER tap is for, it has a very long taper at the front to allow it to guide itself into the hole.  This TAPER tap is fine for almost all situations, the only time you move to the other taps if you want to cut FULL threads to the bottom of a blind hole.  In fact, TAPER isn't that common since a PLUG can really do the same thing.

Did you buy your taps from China?  Every tap looks exactly the same, the taper on all of them appears the same and the last tap with no stripe on it is certainly not a BOTTOMING tap because it has a point on it.

Look at the picture

first look at the post you commented on please

you commented on my very own post with my very own picture taken few minutes before i made the post - showing my very own set of taps which i use to tap threads into heatsinks. and i'm competent enough to know what i'm using

here's the picture again:

[rob77]

Uh no, those stripes identify the tap and you do not have to use all 3 to do a thread.  Single is suppose to be TAPER tap, Double is PLUG tap, None is BOTTOMING.  Really has nothing to do with the thread itself, you will have a hard time aligning a BOTTOMING tap in a plain hole to start it.  That is what the TAPER tap is for, it has a very long taper at the front to allow it to guide itself into the hole.  This TAPER tap is fine for almost all situations, the only time you move to the other taps if you want to cut FULL threads to the bottom of a blind hole.  In fact, TAPER isn't that common since a PLUG can really do the same thing.

Did you buy your taps from China?  Every tap looks exactly the same, the taper on all of them appears the same and the last tap with no stripe on it is certainly not a BOTTOMING tap because it has a point on it.

Look at the picture

even your picture is showing the same as i mentioned - note the progressing sharpens of the cutting edges from left to right and the increasing depth of the groove - so it's a set of 3 taps for progressive taping. (1 strip, 2strips, finish with no strip) - but those are the ones for taping blind holes

i never said my taps are bottoming - mine are through hole.

=== edit - forgot to comment on china

no, i'm not buying machining tools from China . i'm buying those (taps, drill bits, milling bits, cutting disks) in local hardware stores , because those machining tools from china are just toys 

[Monkeh]

'progressive tapping' is an exercise in time wasting for normal applications.

For simply putting an M3 thread in a piece of aluminium, or even mild steel, to hold the minimal torque required for mounting components or covers, a plug tap is the only tap you need. That is the middle one, if you've missed that point.

[tjb1]

Uh no, those stripes identify the tap and you do not have to use all 3 to do a thread.  Single is suppose to be TAPER tap, Double is PLUG tap, None is BOTTOMING.  Really has nothing to do with the thread itself, you will have a hard time aligning a BOTTOMING tap in a plain hole to start it.  That is what the TAPER tap is for, it has a very long taper at the front to allow it to guide itself into the hole.  This TAPER tap is fine for almost all situations, the only time you move to the other taps if you want to cut FULL threads to the bottom of a blind hole.  In fact, TAPER isn't that common since a PLUG can really do the same thing.

Did you buy your taps from China?  Every tap looks exactly the same, the taper on all of them appears the same and the last tap with no stripe on it is certainly not a BOTTOMING tap because it has a point on it.

Look at the picture

even your picture is showing the same as i mentioned - note the progressing sharpens of the cutting edges from left to right and the increasing depth of the groove - so it's a set of 3 taps for progressive taping. (1 strip, 2strips, finish with no strip) - but those are the ones for taping blind holes

i never said my taps are bottoming - mine are through hole.

=== edit - forgot to comment on china

no, i'm not buying machining tools from China . i'm buying those (taps, drill bits, milling bits, cutting disks) in local hardware stores , because those machining tools from china are just toys 

Those stripes indicate type of tap...TAPER, PLUG or BOTTOMING.  What I said was that ALL 3 of your taps look exactly the same from the tip to the taper.  None of the tapers appear to change.  Those stripes have nothing to do with the H limit or class of fit.  You are just wasting your time running all 3 taps through and in a blind hole they will do no different unless they do in fact have a differing tip taper between the 3 which it appears they do not.

Even though the cutting tip is different, you can tap a hole fine with a PLUG tap and run a bolt into it.  Bolts are generally not a sharp point thread either.

[rob77]

'progressive tapping' is an exercise in time wasting for normal applications.

For simply putting an M3 thread in a piece of aluminium, or even mild steel, to hold the minimal torque required for mounting components or covers, a plug tap is the only tap you need. That is the middle one, if you've missed that point.

let me disagree - either you use all 3 of them or you have to use a different single-pass tap (which is more like the last one - without strips) . otherwise your threads will be out of spec (if talking about correct taping/cutting thread)

if you want just screw it "somehow" together - then as others suggested - just skip the taping (gave it a shot in the meantime... well... i'm not impressed thread on the screw flattened, but there are some kind of a grooves in the hole... it was a exercise to screw it in... it withstands a little bit of force... but i wouldn't recommend that )

using just the middle tap only is something in between - but it's better than not taping at all.  i will rather keep spending the extra 1 minute to tap it correctly - use all 3 in the set

[Monkeh]

'progressive tapping' is an exercise in time wasting for normal applications.

For simply putting an M3 thread in a piece of aluminium, or even mild steel, to hold the minimal torque required for mounting components or covers, a plug tap is the only tap you need. That is the middle one, if you've missed that point.

let me disagree - either you use all 3 of them or you have to use a different single-pass tap (which is more like the last one - without strips) . otherwise your threads will be out of spec (if talking about correct taping/cutting thread)

if you want just screw it "somehow" together - then as others suggested - just skip the taping (gave it a shot in the meantime... well... i'm not impressed thread on the screw flattened, but there are some kind of a grooves in the hole... it was a exercise to screw it in... it withstands a little bit of force... but i wouldn't recommend that )

using just the middle tap only is something in between - but it's better than not taping at all.  i will rather keep spending the extra 1 minute to tap it correctly - use all 3 in the set

Your taps are odd, sorry to say. Normal plug taps will fully form the thread, only the first few turns are tapered down.

[KJDS]

'progressive tapping' is an exercise in time wasting for normal applications.

For simply putting an M3 thread in a piece of aluminium, or even mild steel, to hold the minimal torque required for mounting components or covers, a plug tap is the only tap you need. That is the middle one, if you've missed that point.

let me disagree - either you use all 3 of them or you have to use a different single-pass tap (which is more like the last one - without strips) . otherwise your threads will be out of spec (if talking about correct taping/cutting thread)

if you want just screw it "somehow" together - then as others suggested - just skip the taping (gave it a shot in the meantime... well... i'm not impressed thread on the screw flattened, but there are some kind of a grooves in the hole... it was a exercise to screw it in... it withstands a little bit of force... but i wouldn't recommend that )

using just the middle tap only is something in between - but it's better than not taping at all.  i will rather keep spending the extra 1 minute to tap it correctly - use all 3 in the set

Your taps are odd, sorry to say. Normal plug taps will fully form the thread, only the first few turns are tapered down.

As someone who had design authority on about 125 million tapped M3 holes a year into aluminium for five years, I can safely say that not one of those had more than one tap inserted. There's no need to use three taps unless you need the screw to get to the bottom of the hole, and even then I'd usually insist that a design was changed so that wasn't necessary.

[rob77]

What I said was that ALL 3 of your taps look exactly the same from the tip to the taper.  None of the tapers appear to change.  Those stripes have nothing to do with the H limit or class of fit.  You are just wasting your time running all 3 taps through and in a blind hole they will do no different unless they do in fact have a differing tip taper between the 3 which it appears they do not.

once again and slowly.... I'm using those to cut threads - each pass is CUTTING DEEPER INTO THE WALLS OF THE HOLE and is producing chips ....
if you think the TIP of the taping tool has anything to do with the thread cutting/taping process then you're wrong. the tip of the tool  got one job - center the tool in the hole at the beginning. the shape of the tip has nothing to do with the cutting edges of the tool.

and by the way... you have to be the Superman in person , because otherwise how on earth would you be able to see such a details on a 1024x768 picture ? the thread groove depth for M3 is approx 0.25 mm - the difference between the cutters is in the 0.05 - 0.1mm range.... man if you are not the Superman in person then you must have the NCIS , CSI  enhance, uncrop, turbo zoom image processor to see that on 1024x768 

[Monkeh]

once again and slowly.... I'm using those to cut threads - each pass is CUTTING DEEPER INTO THE WALLS OF THE HOLE and is producing chips ....

That's what a taper is for.

Yeesh.

if you think the TIP of the taping tool has anything to do with the thread cutting/taping process then you're wrong. the tip of the tool  got one job - center the tool in the hole at the beginning. the shape of the tip has nothing to do with the cutting edges of the tool.

Taper.

[deth502]

i gotta jump on the pile up on rob77.

i dont know much about electronics, but ive been a machinist for YEARS, and ive NEVER heard of anything like hes saying.

and rob, to comment on your comment about being able to tap a hole "in spec", saying that by itself means absolutely nothing. there are hundreds of "standard fits" for calling out a spec, and non of them need to be used in a print. whatever the tolerances called for in the print are the "spec" on each job. to say just randomly say something is "in spec without a detailed explanation of what "spec" you are working to is meaningless.

and to the op: lots of back and forth and technical talk about taps, if you dont know anything about them, im sure this may be very confusing for you, ever thought of just using a few self tappers? from reading your post i get the idea that this is a "one-off" type of project.  is a fancy tapped hole really worth all of this to you?

[tautech]

35 Years ago when I did light engineering, taps came in Taper, Intermediate and Plug.
There was never any confusion of their names in this way.
They were and still are available singularly or as a set of 3.
If I need to buy one today, I just get an intermediate.

A drill tapping chart is indispensable.
In the small sizes that we mostly use in electronics, attention to detail is the key or you will snap the little blighters. Practice on thin materials and the go thicker as confidence grows. Be careful with anything more than 3 mm thick to start with.
When you have broken a few then you have the feel for tapping. 

We tapped Plastics, Ali, Cast Ali, Mag Ali, Brass, Cast Iron, Cast steel, Mild steel and high tensile steels.
Magnesium Ali, Brass, Cast Iron were the easiest.
Ali and HT steels could be tricky, HT steels just tough, Ali if your taps were a little dull would gall(pick up).

Often for less used sizes we only had intermediates and mostly the holes weren't blind so you could run the tap as deep as was needed.
If your tap was still sharp and not in a blind hole, you could run it as far as needed in one continuous motion, but not in all materials.
Every material is different, some require a cutting fluid, most do not if care is taken.

[ecat]

put

mrpete222 tap

into youtube search and you'll get more advice than you ever need on tapping.

Some good advice in this thread but this is the best I've read. Let me do it for you:



That is part #1 of his series of Machine Shop Tips, do yourself a favour and watch at least the next 10

[Paul Moir]

Those serial taps are not very common in North America.  My handy catalogue has 25 pages of various styles of taps but not one set of serial taps.  I've been meaning to get a set because I do a lot of hand tapping stainless and I thought they'd help, but finding them in inch sizes is very difficult.  Switching between the (very commonly available) taper, plug and bottoming helps but really less total cutting per tap would be less torque.

I think the tool manufacturer's focus their technology more on automated tools, and so taps geared for that work better.  Those guys will never do it in multiple steps if at all possible because they loath tool changes.  But all this is immaterial when tapping Al since it can easily be done in one pass with a traditional hand tap.

One caveat:  I've run across heat sinks that use super gummy aluminium which is a real pain to cut.  I suspect it might be unalloyed.  If you get into trouble don't keep going.  Just carefully work the tap out and clean out the chips.

[ovnr]

+1 for just running a plain M3 screw into your drilled 2.7mm hole. I've done it countless times, and as long as you use some lubrication it's fine. Just be sure to start it straight and for the love of all that goes "bang" when you reverse it: Do not use a power tool. Seriously.

Of course, using a proper tap gives you a nicer finish and less risk of things going pear-shaped (... but I think I've actually broken more M3 taps than when using screws to tap the hole). Just get some spare bits and see how you get on with it.


And no, seriously, you do not need to use multiple taps.

[GeoffS]

Single taps are all that's needed for this application.
Be sure that the tap is at 90 degrees to the work, this will help prevent tap breakages, as will suitable lubrication and backing the tap off regularly to dislodge swarf.
To help with keeping the tap vertical, drill a hole, that just allows the tap clearance, in a 1" block of wood  and use it as a guide.

[Lightages]

Those serial taps are not very common in North America.  My handy catalogue has 25 pages of various styles of taps but not one set of serial taps.  I've been meaning to get a set because I do a lot of hand tapping stainless and I thought they'd help, but finding them in inch sizes is very difficult

Actually you do not want to work stainless too much. It work hardens very quickly. You generally need to make your full thread in one pass. The next pass the surface will have work hardened and you are almost guaranteed to break the tap. So tapping in stages is not a good idea for stainless.

[johansen]

motor oil is fine, but your experience will depend on the aluminum.

pure aluminum is like lead, so your heatsinks have silicon and iron added. iron because they probably threw a bunch of scrap in the pot which had iron in it.

so, you can get away with no grease because the aluminum won't stick to itself. but, most  likely it will just a bit.. a 3mm tap is hard to break off provided you drill an oversized hole which is most likely the case if the bit is dull and it drills a triangular shaped hole. so start it straight and you'll soon get the feel what "cutting threads" feels like.. as opposed to what "smearing aluminum threads off" feels like.
you might be able to get away with a 3/32 drill bit.

[Richard Head]

I have found that an electric cordless drill is excellent for tapping holes. The forward/reverse feature allows one to advance and withdraw the tap very easily. Also, the torque limit can be set to reduce the chance of breaking the tap. It's much easier than using a tap wrench, in my opinion.

[akis]

An unbelievable amount of detail for what I had thought was a simple question. So I deduce that:

1) aluminium is soft enough to force a M3 screw into a 2.7mm hole without prior tapping. Noone has mentioned the thickness of the aluminium here, I presume this holds true for a 1.2mm of aluminium but maybe not so true for drilling into a solid heatsink with thickness of 5mm or more? Anyway I do not think I want to try it.

2) Drill a 2.5mm hole, countersink the top a little bit, then use the hand tool. the intermediate one to slowly cut the threads using some lubrication in the process. If it gets too tough reverse out to remove debris and try again.

3) three general types of tap bits, for starting, continuing and finishing (bottoming) a (blind)  hole. For a through hole the intermediate is just fine.

4) Chinese tools are generally badly made, and I bought this one in the picture - Not sure if this is starting, intermediate or bottoming.

5) How on earth do you drill a perfect 2.5 mm hole? I have a drill press, but am not sure it will cut a good hole, I mean the drill bit has to be perfect, the drill chuck perfectly balanced we are talking Rolls Royce engine quality needed here else it will be a triangular and larger than needed hole, am I right?

[Monkeh]

2) Drill a 2.5mm hole, countersink the top a little bit, then use the hand tool. the intermediate one to slowly cut the threads using some lubrication in the process. If it gets too tough reverse out to remove debris and try again.

Back it up half a turn every turn to turn and a half to break the chips. If you keep going until it starts to jam you'll have a bad day.

4) Chinese tools are generally badly made, and I bought this one in the picture - Not sure if this is starting, intermediate or bottoming.

This is a plug tap, and will be perfectly adequate for soft aluminium. It appears to be a 'gun' tap, so don't use it in a blind hole.

5) How on earth do you drill a perfect 2.5 mm hole? I have a drill press, but am not sure it will cut a good hole, I mean the drill bit has to be perfect, the drill chuck perfectly balanced we are talking Rolls Royce engine quality needed here else it will be a triangular and larger than needed hole, am I right?

A perfect hole? With tools which cost more than your house.

A hole suitable for fixing a component onto a heatsink? Your drill press will be fine.

[Kjelt]

Perhaps Europe differs from the US but I must agree with Rob77 on his statements on his three part tap set.

They are for manual tapping only (not machine tapping where you have a single tap) and for difficult tough material (think steel not alu which is soft).
Now you can argue all you want but have a look at this set for instance which in dutch clearly states "first, middle and last tick" which is exactly how you should use them in tough material, because if you wanted to do it with a one tap turn only it would break or you had to drill the hole larger then ideally so it will not fit as good as should. Have a good look at their start shape, they all are definitely not for bottoming.

http://www.tools2go.nl/9157016/3-delig-m3-x-0-5-tap-set?gclid=CPyPq_jhgL8CFaQIwwod62IA_Q

That said, for aluminium you can just use a machine tap or one time tap, no problemo.

[KJDS]

It's unlikely to matter if you're just screwing a transistor to a heatsink if the hole is a little oversize. Unless you need to tighten teh screws up too their maximum otrgque on minimal thread depth then using a cut tap in  a 2.6mm hole won't make much difference.

[rob77]

An unbelievable amount of detail for what I had thought was a simple question. So I deduce that:

1) aluminium is soft enough to force a M3 screw into a 2.7mm hole without prior tapping. Noone has mentioned the thickness of the aluminium here, I presume this holds true for a 1.2mm of aluminium but maybe not so true for drilling into a solid heatsink with thickness of 5mm or more? Anyway I do not think I want to try it.

2) Drill a 2.5mm hole, countersink the top a little bit, then use the hand tool. the intermediate one to slowly cut the threads using some lubrication in the process. If it gets too tough reverse out to remove debris and try again.

3) three general types of tap bits, for starting, continuing and finishing (bottoming) a (blind)  hole. For a through hole the intermediate is just fine.

4) Chinese tools are generally badly made, and I bought this one in the picture - Not sure if this is starting, intermediate or bottoming.

5) How on earth do you drill a perfect 2.5 mm hole? I have a drill press, but am not sure it will cut a good hole, I mean the drill bit has to be perfect, the drill chuck perfectly balanced we are talking Rolls Royce engine quality needed here else it will be a triangular and larger than needed hole, am I right?

1. don't do that - you will be not able to say if the 1-2 Nm torque is coming from the friction of the screw or from tightening the packege to the heatsing , so you might end up with poor thermal junction. i gave it try yesterday and it's nothing you would like to use in any of your projects probably works better with pure aluminium but with the alloys i have it's not usable (ok. it holds the screw in place to some extent, but i don't recommend it).

2. half turn back every 1-2 turn for small diameters and softer metals, for larger diameters half turn back every single turn.

3. that tool is a single pass - and looks good - at least it's hardened according to the different color.

4. a decent drill press shouldn't have more than 0,05mm eccentricity  so no problem. if your drill press has more, then a good trick is to use smaller drill bit - e.g. 2,4mm one to get a 2,5mm hole

[Monkeh]

Now you can argue all you want but have a look at this set for instance which in dutch clearly states "first, middle and last tick" which is exactly how you should use them in tough material

And taper, plug, and bottoming taps are commonly refirst to as first, second, and last taps. I think you'll find all three of those are exactly the same past the first ten threads at most.