Drill Bits

J

jhowes

Well-known member
I am about to buy some new drill bits an wondered if some one on this forum knows the difference between Titanium and Cobalt high speed steel. Not exactly Model A but???? Jack
 
My understanding, possibly wrong, is that the titanium coating is just that. If you sharpen a bit, the coating is gone. Also, the coating probably could be put on lower or higher quality alloy bits. Cobalt is the material the bit is made of, through and through. It's the toughest material I know of and consequently is also pretty difficult to sharpen and is quite expensive. Might look at a machinist's handbook.
 
What 100IH and Bill said is exactly correct!! Coatings are just that, they wear off the cutting edge and then you are at the mercy of the parent metal. Buy a good quality cobalt bit, they are worth the extra cost.
 
My vote is for cobalt, stay sharp longer! High speed and high heat will kill bits. I was instructed that if you have to stop your drill motor, keep pressure on the bit to metal contact area, thus allowing heat to transfer from the bit back into the metal.
 
We all know this but sometimes we don't want to believe it.

You get what you pay for.

Good drill bits last a long time. When I worked in a machine shop a hundred years ago, Chicago Latrobe was the one. No coating, no gimmicks.

Rely on a material speed chart and the bits will out live you.
 
Larry Jenkins said:
We all know this but sometimes we don't want to believe it.

You get what you pay for.

Good drill bits last a long time. When I worked in a machine shop a hundred years ago, Chicago Latrobe was the one. No coating, no gimmicks.

Rely on a material speed chart and the bits will out live you.
Click to expand...
How cheap or how quality conscious are you? If cheap buy from HF. The good bits come from an industrial supply place and cost more. Treat yourself to the good stuff.
 
It depends upon what you are doing.
If you have one or two holes to drill get Harbor Freight drills, use them once and throw them away.
If you want a lifetime tool and you are young, middle aged, or want to leave your kids with good tools go with the expensive ones.
 
Larry Jenkins said:
We all know this but sometimes we don't want to believe it.

You get what you pay for.

Good drill bits last a long time. When I worked in a machine shop a hundred years ago, Chicago Latrobe was the one. No coating, no gimmicks.

Rely on a material speed chart and the bits will out live you.
Click to expand...

Sometimes you don't. Recent information that some Snap On is made in Japan and China. So much for the Big Shooters! Wayne
 
Back about a hundred years ago, I worked in a machine shop. I was able to stock myself with all the fraction, letter, and number drill bits. Over the years I have lost and/or broken a few, but still have about 90% of them. When I go to replace them, I will go to our local Industrial Hardware store to get them. They can't be beat.
 
Prefer tin coat and cobalt mix
Called UB drills by the manufacture. All drills wear due to too much heat and or speed. But UB drills are what I use at my shop most of the times. All depends on materials too. If I were to buy go with 135degree split point hold up better
 
It all depends on what your going to be drilling, if you look on the packaging most drill bits list the materials they drill as plastic, wood, metal...meaning their made to drill softer materials...cobalt bits are the only ones made to drill steel...and as stated before rpm does matter especially when drilling thick material...I suggest the slowest speed you can get your drill to run preferably a press...I also stand by using a good cutting oil as your drilling since it will make your bits last a lot longer...as for a drill bit sharpener I've got a drill doctor I bought years ago that I've only used a few times...just easier for me to replace rather than sharpen...I typically buy a set of cobalt bits once a year always Irwin or rigid and I drill a lot of heavy plate and steel on a daily basis...just the worthless opinion of a old metal fabricator mind you...
 
After taking a term as a machinist and continuing to work with my lathe/mill I buy all my drilling/milling tools from here;
http://www.rlstephenstool.com/

If they don't have what you want in stock, they can have it quickly for you.
These guys are the best!

My 2¢
 
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