Drill bit set recommendations?

[pontiac428]

I bought more and more expensive 115 piece drill sets to get one so expensive I will put a drill away when done.

It did not work. I am too cheap to use the expensive drills, so I use the cheapest ones.

The wife says I should put tools away like Blondihacks.

Buying good drills is one sure way to make sure they are not only put away every time, they are put away sharp and shank-deburred.

At least I know I always have a cobalt stub drill on deck in 115 sizes. That's priceless when in the flow of a project.

 

[cazclocker]

I've been using drills with the black oxide coating for years, and I recently had an opportunity to try drilling 1144 stressproof with both a cheapo drill and a Chicago-Latrobe M42 cobalt drill. I found the CL cobalt drill FAR easier to penetrate the stressproof. I'm beginning to see the value of quality drills! Now if I could only afford a full set metric, wire size, letter size, and fractional in cobalt!

 

[cazclocker]

....which leads me to a question. When shopping for a drill bit set, does the term "M42" always mean the cobalt content is 8%? Aren't there other cobalt percentages available, and what are their advantages?

 

[pontiac428]

A sample of alloying compositions of common high speed steel grades (by %wt)[10][11] (impurity limits are not included)

Grade	C	Cr	Mo	W	V	Co	Mn	Si
T1	0.65–0.80	4.00	-	18	1	-	0.1–0.4	0.2–0.4
M1	0.80	4	8	1.5	1.0	-	-	-
M2	0.85	4	5	6.0	2.0	-	-	-
M7	1.00	4	8.75	1.75	2.0	-	-	-
M35	0.92	4.3	5	6.4	1.8	5	-	0.35
M42	1.10	3.75	9.5	1.5	1.15	8.0	-	-
M50	0.85	4	4.25	.10	1.0	-	-	-