Thread: What's a Tap cost these days?

Do they even make Cobalt HSS taps? I thought the cobalt gave the HSS better heat resistance? Taps don't really get hot. Not at the glacial speed I use them anyway.

Originally Posted by jack620

Do they even make Cobalt HSS taps? I thought the cobalt gave the HSS better heat resistance? Taps don't really get hot. Not at the glacial speed I use them anyway.

I cant say for sure that they do make cobalt HSS taps, but I imagine that they do. After all they do make cobalt HSS drill bits, and even solid carbide taps, so I think it likely that Co HSS is also used for taps.
Rob

The non name brand taps I've bought from Ebay (small sizes only) have been excellent and not broken.

I only buy them if they are stated as rated for stainless steel, and have not had a problem.

One thing I notice about them is that they spring (twist flex) more than others and are not as brittle - which is a good thing as you can judge how much load you a putting on them better.

One no name Ebay cutting item I HAVE bought which has been regrettable were some small centre drills which have all been very brittle and it's a PITA when they break and you have to remove the stuck fragment/tip.

I really hate that.

Cheers all

Rob

Originally Posted by nearnexus

One no name Ebay cutting item I HAVE bought which has been regrettable were some small centre drills which have all been very brittle and it's a PITA when they break and you have to remove the stuck fragment/tip.

I did exactly the same thing with a "no name" centre drill 2 days ago while drilling aluminium of all things! How do you get the busted bit out Rob?
I'll be sticking with my P&N centre drills from now on.

Originally Posted by jack620

I did exactly the same thing with a "no name" centre drill 2 days ago while drilling aluminium of all things! How do you get the busted bit out Rob?

With great difficulty.

I generally try using a small centre punch on them to smash them up and sometimes they fall out.

If that fails I try a small ball headed burr in the die grinder to chew them out. That often works.

It it's the end of a shaft it's a real bummer as it's going to then be hard to centre drill it again properly (larger size) as everything goes pear shaped regarding centre point.

If it's possible and it's thick sheet/metal plate it's best to turn it over and try again from the other side - this usually works out OK, but it pays to go up a few sizes in centre drill size to avoid damaging it if/when it hits/pushes out the left over stub - which it can do. Generally I would not centre drill very deeply and use a larger starter drill than normal to reduce deflection if any remnants are still in situ.

All in all, it's the thing I hate most when machining, coz it can really stuff you around big time.

Cheers

Rob

OK, thanks for the tips.

Originally Posted by jack620

I did exactly the same thing with a "no name" centre drill 2 days ago while drilling aluminium of all things! How do you get the busted bit out Rob?
I'll be sticking with my P&N centre drills from now on.

You could tryba strong acid that doesn't react with aluminium. Nitric?

Greg

I've only broken a centre drill once in recent memory, and I just turned the end off the material and started again. Not always possible of course. I can't see why they should break unless either they are dull or they are fed too hard for the speed. 30m/m at 3mm dia comes out to 3000 rpm. Slower is ok, but you need to be patient with the feed.

I've broken a few centre drills over the years, always small ones, and invariably when centre drilling something hard like a (high tensile) bolt or steel plate.

Even being careful, in the small sizes if they are brittle they can/will let go, you are not going to be happy.

Larger sizes are not a problem - well for me anyway.

Cheers

Rob

I've broken lots of taps over the years, anything up to 1/4", always P&N or Sutton, mostly because that's all I had. In the mid 90s I lived and worked in Malaysia for a couple of years and while there I bought up big on taps and dies, drills, wad punches, drop saws, micrometers, reamers, end mills, a milling machine, electric motors, a box of 100 cut off wheels, all sorts of stuff. Most of the stuff has long gone (broken or worn out), but I still have all the micrometers, taps and dies (no brand name) and locally made scissors, I use these things for cutting everything from cloth to gaskets to sheet metal, they just won't wear out or break. Funny thing about the micrometers, three of them were cheap Chinese, the fourth was a Miyotoyo, guess which one broke!

Originally Posted by tongleh

Funny thing about the micrometers, three of them were cheap Chinese, the fourth was a Miyotoyo, guess which one broke!

Which one did you use the most?

The Mitotoyo is a 25-50mm, all the rest are Chinese. The most oft used one is the Chinese 0-25 by far, followed by the Mitotoyo 25-50, then the Chinese 50-75 and 75-100. I've had the same luck with small angle grinders: Three Makitas (2x4" and 1x6"), all on the scrap heap within a couple of years. My Chinese 4" I've had for about 4 years now, still going strong. Having said that, I'd have to mention my Hitachi 9" and also the 1/2" drill, I bought both back in the 80s and both copped an absolute hammering, but both are still going as strong as ever. The 9" switch went yesterday so I'm tossing up whether to buy a $98 cheapy or pay almost the same amount for a new switch. Hitachi=GOOD.

We have the same problems here across the pond(USA), only reversed. A good 1/2" tap is around $4-5 USD. On the other hand a couple of flat head brass 3mm X .5 screws are made of Unobtanium in Americum.

Originally Posted by mcostello

On the other hand a couple of flat head brass 3mm X .5 screws are made of Unobtanium in Americum.

Slightly off topic, ..

Have you tried the electronic suppliers? Like Newark? Machine | Newark

Regards
Ray