Which drill/tap set to buy?

[Richard.]

Dormer is my choice of taps and dies. I use them quite a lot so will buy good quality. For run of the mill drill bits presto are pretty good and a full set can be had for sensible money. I have a set and there performed pretty well. I've even used successfully with stainless drilling. They are not the best of the best by any means for high speed metal drills but they are a capable drill for sensible money.

 

[BrokenBiker]

I have the rdg set, paid 35 for mine but didn't come with a tap wrench. I have used the m6 m8 and m10 taps a lot on the megane, mostly in Ali castings and for cleaning up holes etc but have also used the m8 a lot on steel and it's still going well. Have had the set about 2 years, maybe more and they are still as sharp as when they were new.

 

[Johnseat]

So go on people, educate me on the different types of taps there are.

 

[Maker]

So go on people, educate me on the different types of taps there are.

Taper is the first tap you use to tap a hole, it has partial threads for most of it's length so it is easier to start.
Second, as the name suggests, is the tap you would use second, it only has the first 1/4" of teeth ground back. As people have said, they're rarely used and fairly redundant.
Plug or bottoming is the last tap you use, it has only the first tooth ground down, it's used to get threads right into the bottom of a blind hole.

 

[Johnseat]

What about machine taps, spiral taps and so on.

 

[optima21]

spiral point taps, for through holes in thin metal as the cuttings are forced ahead of the tap, spiral flute taps for blind holes as the swarf goes up the flutes, fluteless taps for forming the threads in softer materials rather than cutting them

 

[graffian]

it had a blue sticker with black wrighting and I'm almost certain the make was 3 letters like HTE or something.

OSG?

 

[Spark plug]

What @Maker has just described are known as straight flute hand taps and are designed to be used by hand in a half turn forward - half turn back manner.

Ware as machine taps are designed to be used in a machine, be it mounted in a tapping head or a CNC milling machine etc. Machine taps are designed to be driven into a hole in one continuous motion then extracted when the required depth is reached.

Machine taps fall into two categories spiral point and spiral flute. Spiral point being designed for through holes in reletivly thin material as these are designed to push the swarf forward and out the bottom of the hole. Spiral flute taps on the other hand are designed for blind holes as these have a continuous cutting action and the swarf is ejected along the flutes in one long curly string like the swarf from a twist drill. Spiral flute are much more common than the spiral point type because they will tap through holes just as well as blind holes.

Then there is the flourless tap witch is used to form the thread rather than cut it, these are ideal for more malleable materials, these can also be paticularly usefull when the thread requires high strength as there in no material being removed the parent material isn't weakened. Care should be taken if the hole is close to the edge of the material the flourless tap can cause deformation to the outer faces of the material.

 

[Welderpaul]

We use fluteless (or roll taps as they are known) in flow drilled holes.

 

[Spark plug]

OSG?

I don't think so but could be wrong, I think all the markings on the shank are worn off.

 

[Maker]

I believe I read somewhere that spiral flute taps are weaker than straight flute so they shouldn't be used my hand as they are more prone to snapping.

 

[Spark plug]

I believe I read somewhere that spiral flute taps are weaker than straight flute so they shouldn't be used my hand as they are more prone to snapping.

They do snap quite easy when used by hand, not from turning too hard usually from wobbling side to side.

 

[optima21]

ohh now you tell me spiral flute taps are fragile, hope the 16mm spiral flute tap I got last week for use a hob to cut a worm wheel will work.

although I will be using the tap supported with a centre in my lathe

 

[Ben88]

I've got the sealey tap set with drills think it was £70, tapped an m6 thru s/steel 30mm depth no problem other day

 

[graffian]

Here's a pair of spiral 7/16unf and a 3/8 unc roll tap. it should be pretty easy to guess which is strongest.

 

[brightspark]

which one then and explain why 2 cut and one rolls. how much torque needed

 

[Tiggy_dorset]

Dormer set arrived today from Cromwell. Sexy as...
*looks for the 'like' button*

 

[langy]

Once you have decent quality taps you will realise what junk RDG are !!!
Look for Blue Wizard, True-Cut, Presto, Dormer etc etc, you will have them for years

 

[Spark plug]

Once you have decent quality taps you will realise what junk RDG are !!!
Look for Blue Wizard, True-Cut, Presto, Dormer etc etc, you will have them for years

That's exactly it with any cutting tool, I only buy RDG and the likes when I have an odd ball repair job and I can't change the thread to something sensible.

 

[ronan]

To be fair to rdg, they are aimed at the model maker and fella's messing about in sheds. I bought a collet set off them for the mill a couple of years back, it was the same price or less than a 50 year worn out old non-chinese/indian made set, its perfect for what i do.