Thread: 2 tapping questions

If yer looking at the flea markets, you might get lucky and find either cobalt HSS or possibly tungsten. Cobalt is better than HSS in that's it just more of everything, including the price. Tungsten is good if you are tapping nasty stuff like stainless or titanium regularly, problem is that it's brittle. That means where a HSS tap will let you know it's not happy, the tungsten will snap in the hole, and you are not going to get it out in any kind of hurry, if ever.

Don't restrict yourself to Suttons and P&N though, plenty of good stuff under other brand names, I just can't recall what they are right now. Generally, if it's nice and crisp and looks good, it will be a quality tool.

Going price last time I was at Wantirna was $1-3 per tap, all never used. Might also want to check out Pete's bargain centre in Croydon (?). He usually has a lot of that kinda stuff, some junk but some good and all very cheap.

And don't buy a used tap. Old never used ones are cheap enough you shouldn't have to buy a used one, unless it's a monster.


(BTW, if you see any endmills, I'll buy them off you!!! Might be a while before I can get there to pick them up though... )

May ask what might seem a "SILLY" question?
What are you Tapping:confused: :confused:

Some time back I TAPPED some well seasoned Hardwood.
It worked very well. Mind you, it was quite a coarse thread.
On a par to Coach Screws.

Originally Posted by Ivan in Oz

Some time back I TAPPED some well seasoned Hardwood.

Haha. I tapped some softwood once for testing. Terrible thread. It needs to be drilled undersize because of the fact it's much softer than metal and the drill will easily make a bigger hole if not clamped securely. When I did it, the tap practically fell right through
Some cheap taps and dies can be OK for aluminium and maybe brass, though it's still not a pleasurable experience.

Originally Posted by Schtoo

And don't buy a used tap. Old never used ones are cheap enough you shouldn't have to buy a used one, unless it's a monster.

Just what I was going to say. Thats one old tool I'd never buy from a flea market. Unless maybe your tapping wood.

Buy new, I reakon,,,, heaven forbid you break one off in a hole.

Last tap I broke was in the main ways for my lathe. Made a funny noise, then snapped off, leaving a little ugly bit sticking out, but not enough to get a hold of.

Ended up having to bash it through with a punch, then tapping the next size up. Luckily, I got a nice plug tap in the bargain.

I have tapped so many threads lately, I don't even check to see if it's square and true any more.

Oh well, with any luck by Sunday the thing will be running well enough for it to do it's first job. That will make me very pleased as I have wanted a lathe for over 10 years now, and I am so close now I can taste it.

Prolly a bigger high than my first casting.

If you find time, Schoo ....love to see a picture, ya smartypants.

I took some, but left the camera at the workshop.

And the workshop is a 30 minute drive away...


The fun part is working out the order of making spindles, tailcentres, tapers and whatnot. Think I have it worked out now, but I am sure I'll blow it.

Just hope I get my 'steel' tomorrow morning.

Originally Posted by Edd

Haha. I tapped some softwood once for testing. Terrible thread. It needs to be drilled undersize because of the fact it's much softer than metal and the drill will easily make a bigger hole if not clamped securely. When I did it, the tap practically fell right through
Some cheap taps and dies can be OK for aluminium and maybe brass, though it's still not a pleasurable experience.

Regularly tap MDF for jigs.....no probs.
For tapping aluminium use kero as a lubricant...or WD40.

Old taps are pretty hard, aren't they? The smooth shaft could make a good rod for a scraper burnishing tool methinks


Cheers...............Sean

Uhh, yeah they would.

So would old drill bits...


Or, you could do what I did, and just buy some HSS rod, which arrived with the steel I got today. About $3 for a 6" length, but supremely useful stuff to have around...

I usually use a pin punch for scrapers myself.

Gday Schtoo, thought the tap might be harder than drill bits.

Prob either will do anyway, both sufficiently hard I guess by the sounds.


Cheers................Sean, tapped out

Well, come to think of it neither are as hard as they could be.

Yer prolly right, the taps are harder as they can and do snap, but you have half the body missing where it cuts, then a bunch of stress risers in there too, plus they are often hand held, etc, etc, etc. They have lots working against their longevity so I would think they back the temper off much more than might give an optimal edge.
The drill bit gets lots of stress because half it's bulk is missing, and it also under power and often bends in the hole. They be a lot softer than they could be to put up with that.

Next burnisher I'm going to use up a certain drill bit if it gives me any more trouble, particularly if I can't sharpen it well enough...

Solid tungsten.

Prolly be the most expensive burnisher on the planet.