Hi Peter,
I tend to agree with you on the “WTF” factor with that particular
price, but there are reasons why one might choose to pay much, much
more for a quality drillbit rather than just using the cheapest
random Chinese crap. Production being the obvious answer.
For the drills and taps Lee and I use for the clamps on the KC saws,
we’re using drillbits that cost $30 each (in bulk), for a 1/16" bit.
No, that wasn’t a typo. $30 EACH. Equally, the little drills that do
the hole for the blade cost in the neighborhood of $15 each. (and
the taps are about $15 a shot as well.)
The reason we go with those insanely expensive bits is that they
LAST, and that they’ll let us cut faster, which in the long run,
makes them much cheaper.
Figure it takes me 5 minutes to change and re-zero a blown drillbit,
plus another 5 minutes to hand edit the program to skip to the next
undone section, and avoid the part with the busted bit in it, that’s
10 minutes per blown bit. At $200/hr for the machine, that’s $33 in
time per blown bit. The $30 bits last, on average, something like
500 parts, while the best we were getting before, even with name
brand US bits was something on the order of 80 parts per bit. That’s
about 6/1, so figure the normal bits would have cost me $200 in time,
nevermind the scrapped parts. The $30 bits also let me boost my
drilling speed by 1/3, so I’m saving $200 in changeout time, plus
1/3 on the cutting time. (figure 180 minutes saved over 500 parts,
roughly. That’s $600 in time savings.) Add that together, and you
save $800 per bit, by using what would seem to be insanely expensive
bits. Looked at in that light, I can’t afford not to use them.
Once you get into CNC and production, a lot of those “holy crap
that’s expensive!” tools and bits suddenly start making a whole lot
more sense.
Regards, Brian
PS–> I’ve used Interstate taps…NEVER again. Ever. They’re
actually coming out of former Yugoslavia somewhere, but they’re
incredibly brittle. At one point, I blew 6 of them in a row rigid
tapping on some 8/32’s Six holes, six blown taps. I switched out to
decent Balax taps, and did the next 80 or so without a single
problem. (So it wasn’t the program or the machine, it was the taps.)