Drill bits - split point? chisel point? 118-degree? 135-degree? Coatings? Arrgghh!!

Split points are no more than a regular drill bit with a thinned web, I f you start a hole with a smaller bit the web is inconsequential. For a hobby machinist anyrhing other than black axide is a waste.
Screw machine lengths are desireable for use withg a mini mill/drill where the distance to the work piece is short. Thin the webs yourself as you need them. When drilling brass hold the cutting edge of the drill againsrt the side of the grinding wheel for a neutral rake. You can also grind brad points yourself as required . we used to call them "tin drills".
Hope I helped.
Ron
 
ronzo said:
Split points are no more than a regular drill bit with a thinned web, I f you start a hole with a smaller bit the web is inconsequential.
Click to expand...

Ron,

A drill bit with a thinned web still has a chisel point, which means that it will walk if started without a center drill. A split point drill comes to a sharp point which makes center drilling pretty much unnecessary except for very small bits.

Tom
 
For me, I'd just go with 118 degree black oxide. When sharpening is required, go with a nice 4-facet grind and you're set for life.

I can't add much that hasn't already been said, but buy yourself some nice Huot cases for them! Huot makes a screw machine length index for Fractional, number and letter bits. It's quite nice like all the stuff the make.

John
 
I have a black oxide set I purchased 40+ years ago.
I have only learnt to freehand sharpen recently so I usually went with the buy new.
Now I am going through the set re-sharpeneing as I need them, feels good.
Not complete as a few have broken but what I really miss in new drills is the recessed section at the fixing end that has the size etched where it doesnt get rubbed off if the drill spins in the chuck (or am I the only one who has had this problem)
 
Yes, I too miss the older style drills that the size was stamped on instead of the newer ways of etching that rubs off easily.
 
ronzo said:
Split points are no more than a regular drill bit with a thinned web, I f you start a hole with a smaller bit the web is inconsequential. For a hobby machinist anyrhing other than black axide is a waste.
Screw machine lengths are desireable for use withg a mini mill/drill where the distance to the work piece is short. Thin the webs yourself as you need them. When drilling brass hold the cutting edge of the drill againsrt the side of the grinding wheel for a neutral rake. You can also grind brad points yourself as required . we used to call them "tin drills".
Hope I helped.
Ron
Click to expand...

I'm sorry guys, I don't know the terminology. What is a web as it pertains to drill bits, and what means "thinned"? Does that mean some webs are thick? How did spiders get involved in machining anyway? Just kidding...:rofl:
 
I know i am a little late coming in on this one. But i would suggest that you buy a real good set of split points bits up to 1/4 inch. If you watch for sales you can get them pretty cheap. then use regular bits for sizes after that. You are going to use a pilot bit for larger sizes anyway. I also like using short bits, rather than jobber length bits. Also save your bits from sets for when you need an exact size. pilot and drill junk holes with bits that are sharpened from the flea market box. Then finish with your good bits. Titanium Nitride coated bits ,gold colored, are slightly better for steel, but do not do well with aluminum. And if you are drilling a lot of holes with a hand held drill, DO GO for the split point, Or the bullet point, which is a split pointed and trunkated nose. they wander less, push way easier, and most of the time do not require a pilot hole. The bullet point bits also have the advantage that they do not grab when going through, like regular bits do. The disadvantage of bullet bits is that they do not give you any warning before going through so if you are pushing hard they go all the way to the chuck before you can stop them. I have drilled like a million holes at work.
 
What has not been mentioned is the use of a center drill. Very useful to start a hole after center punching the hole position. Nice and stiff. I use # 2, 4 and 7 as required.
Pierre
 
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