Send me a message if you can help.
I am always looking for used Cobalt TS drill bits in the following sizes:
9/16" dia. in usable length. Maybe 4" of useable length but less if reasonable priced.
1-1/16" min dia. up to 1-3/16" dia. in short lengths. 1" of usable length minimum.
Have to be Cobalt
Do not want Chinese bits but European, Japanese and of course USA are good.
Straight shank or S&D do not work.
Carbide does not work.
These are used to drill stacked AR400 plate, then C'sink each individually. This is done on a old, heavy radial drill that can be run super slow.
Once in awhile they can be found on eBay or even Amazon if on sale. Neither is consistent.
We have been doing this for over 15 years and only lately running real low on drill bits.
Last year I retired for good but gave the shop to my daughter so have to take care of some things for her.
And, I still sell the "L" taper lathe chuck spanners from the AR plate drops. Just have to get my daughter to cut them. Sold plenty of them thru Practical Machinist. No complaints yet.