Thread: Which Tap & Die set to purchase?

Originally Posted by RayG

Hi Brett,

Dormer are excellent, Sutton are good, Greenfield are up there.... don't buy sets.. get them as you need them, taps usually come in sets of 3.. plug, taper, bottom..

I've got mostly hand taps ( straight flutes ) but I'm seriously thinking of gradually going over to spiral taps, probably Dormer.

Ray

PS.. Most of the hardware/fastener places around here now carry "Goliath Brand" taps... they seem ok for the few I've used..

I think you are allowed to buy the "sets of 3.. plug, taper, bottom." Just don't buy complete sets of taps/dies etc is probably what Ray means.

Dean

Brett, for casual use, have a look at garage sales. I have picked up a drawer full of P&N & others over the years.

I even managed a 500ml container of Trefolex Cutting compound for the princely sum of $2.00.

The correct drill bit for the tap is also helpful, you can ream out a hole if it is a smidge tight, but you are in a world of woe if the hole is oversized for the tap.

Hi Brett,
I looked at the Aldi tap sets when they were here a few weeks back. They are metric only, carbon steel made in China. I wouldn't be holding my breath.

I'm with most of the other guys, buy good ones as you need them. Or buy a cheap and nasty set, and buy good replacements for the ones you break. That way you only buy the ones you really need.

UK ebay is your friend!

Ew

Brett,

a set of inexpensive but well made Japan made carbon alloy straight taps and unsplit dies can be an excellent starter kit. Not sure if you still can get them. They look like this set and used to cost about $120 each for a metric set.

You soon find out which taps or dies you use most, and will buy these as fully ground brand name spiral point HSS. You soon learn which materials are better cut with a set of three taps. And you soon discover that blind holes are best cut with spiral flute taps that eject the chips upwards.

These are two places that I recommend to buy good brand name taps from at reasonable prices (some of these taps are unused old stock, but who cares if they are good):
cncpoorboy toolstore items - Get great deals on items on eBay Stores!
jow1995 items - Get great deals on METRIC, BSW items on eBay Stores!

Do not forget to buy a set of drills to go with the taps. The correct size drill is very important. You cannot just use a drill set of 0.5mm increments, if you try you break taps or make threads that strip out quickly. You need to buy the proper size.

You also need some good 90 degree countersinks if you want to properly tap holes. Just using a larger drill to countersink is not very satisfactory.

Over time you will also want to buy better quality wrenches. Used ones of good brand name and made of steel are a far better choice, than new ones with cast body that come with cheap sets and break just from looking at.

You also need something to guide your taps when hand tapping. Easy to make your own from some scrap metal. But look at these for inspiration:
Complete SET OF 6 Guides BY BIG Gator Tools TAP AND Drill Guides | eBay

For steel use something like lard to lubricate taps, for Aluminium use WD40. Or buy some tapmatic fluid or similar commercial product. Taps stay longer sharp and break less if generously lubed.

Australia is now metric, like most of the world. You may be best off starting with a metric tap/die set, unless you need to work on an old car (new cars are largely metric even if made in the US). If you work with water/air/oil pipes you may need a few sizes NPT taps/dies. In general, I try to rather substitute metric threads for imperial ones, rather than buy imperial taps that I only use for one job and then never again.

Chris

Originally Posted by variant22

Can you please post a reference? Assuming we are talking about the same thing, I have not seen a separate drill size chart for spiral fluted taps. They seem to use the same sizes as hand taps.

You mean a chart with drill sizes for straight flute, spiral flute and spiral point? nope, I doubt there is one. Though to quote your link which says the same sort of thing only backwards. "This gives the spiral point tap more cross-sectional area, which means greater strength, allows higher tapping speeds, and requires less power to drive."
As I said its not a case of "you cant do that!" just more likely to break something.
With a three tap set and to tight a hole you can go taper, int, bottom, taper, int, bottom......... Its a little on the slow side though lol

Stuart

Amen to Pat's comment above. Haunt the garage sales, swap meets and fleamarkets. Much of the stuff from deceased estates etc.will be quality brands, some long gone, but excellent. You can re-sharpen dull taps with a small stone on a Dremel tool or similar. Just undercut the leading edges of the flutes slightly till they feel sharp again. Dies will take the same treatment if you have a small enough stone. Older tap and die holders are usually much better than most of the stuff I have seen lately. For my vintage machinery restorations I have picked up at auction sets of Whitworth/BSF taps an dies to 1" , BSP pipe dies and guides, UNC/UNF sets, and a Metric assortment in addition to various Morse Taper drills. They are out there, keep looking! Combustor.

Hi, I found it very helpful to have a copy of the engineers black book or something similar on hand when buying stuff on epay, I discovered the hard way there are a few "non standard" thread pitches out there that pop up, often you think you have a bargain, when upon closer inspection you have ended up with an orphan.
It lists all the correct drill sizes too.
I find a set with the correct size tapping dills included was great as its not that easy to get he odd drill sizes needed individually without going to a specialist store.
Sutton Heritage 26 Piece Metric HSS High Speed Steel TAP Drill SET T901HM26 | eBay

Regards
Bruce T.

Thanks for the next batch of answers - more great info and advice. Stuff I would never have considered!

Bruce T's comment also reminded me of something else, you can get oversized (and probably undersized) taps for tapping before heat treatment etc. They are of no use for normal work though.
My local shop has sets of Guhring gun nose taps and matching drills, i think they are M5,6,8,10,12. Top quality HSS, about $130 from memory. Considering the list price on a Dormer M12 is about $60 thats pretty good value. You will find better on ebay though.

Ew

More advice get yourself a copy of the #12 Workshop Practice series "Drills, Taps and Dies" by Tubal Cain.
Just the tables in the back are worth it.

In relation to imperial I generally find Whitworth the most common. So i guess it depends on what your working on.

My suggestion would be to go to super cheap or equivalent and buy a $50 set, which will be fine for brass, aluminium and soft steel and see what you use then replace those with a qood quality HSS ones.

There are also number sizes and tap drills often (even for metric) come from a different standard of sizing.

I'd also get my tap wrenches etc from swapmeets and garage sales for good quality at cheap prices, so go for round dies as they are more common than hex. The other things is buy a few sets of thread pitch gauges, they look like feeler gauges with teeth. This will allow you to know what tap or die you need for an existing mating part.

The Aldi set also happens to have correctly* sized drill bits and a thread gauge...so for $25 it's not a bad start.

*apparently...I haven't checked 'em against Machinery's Handbook specs.

Originally Posted by Master Splinter

*apparently...I haven't checked 'em against Machinery's Handbook specs.

Not the most authoritative source of information about metric threads. The machinery Handbook is an excellent American Hadbook. But as such it describes the current (early) American implementation of the metric ISO system. It is a bit like in the early days of metrification in Australia, when clearances under bridges were signposted as 3.657m (12 foot). You end up with things like designers using rather exotic metric threads, like M7 and M3.5.

...But Machinery's Handbook has the overwhelming advantage of being easily and freely available...