Drill bit preferences

P

PT Doc

Joined
Dec 24, 2011
Messages
1,298
There has been quite a bit of chatter about bits recently on this forum and others. We all use them and have preferences and hate others with a passion it seems. I would be interested in hearing what types of bits you guys like. Important info would be:

Drill Material: material M2 hss, m35 cobalt hss, m42 cobalt hss, carbide
Material being drilled: ss, mild...
Bit finish: black oxide, bright, TiN coated, other coatings
Tip config: 118*, 135* or other angle split point
Length: jobber, mechanics, screw machine
COO: USA, European import, Asian import
Problems: short life, chipped edges, out of round holes, excessive down feed needed

Thanks for providing the info.
 
Last edited:
My previous bits were

M35 cobalt
Standard cobalt finish
135 split point
Jobber
Asian import
Only problems have been ground/sheared relief angle likely from poor bit alignment one time in a hand drill and he other was likely from a non evacuated chip since this was in a drill press or possible that was bit failure due to poor quality or hitting a hard spot in the mild steel 1/2" plate

I just got some new bits that are different from all the above spec besides 135 but have not tried them yet so I'll leave them out until I try them.
 
I like bits that have the size rolled / stamped in.

That electro etch marking is very hard to read after some time.



That gold coloured coating doesn't seem to make any difference in the cutting for me, but it helps me to keep my sets separate

Fractional, number, letter

Gold, bright, black oxide
 
I recently tried a set of twist drills from one of the big home centers. The brand is Ridgid and the line is called "Cold Fire". I'm not sure what they are made of ( I checked the website but no specs listed) but they are cryo treated and have been working very well for me.
 
Living in the metric world I have a set of cobalt drill bits 1-10mm per 1/2mm. The smaller ones brake but I buy replacements on-line (cheaper then the store)
I like the cobalt bits they cut well
 
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