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

[OakRidgeGuy]

I just picked up a set of center drills, numbers 1 - 5, they will get used rather often. Even if you do have spit point drills, it does not hurt to have the enter drills.

Oh and Steve brings a point, my eyesight is such, that I can not see anything up close with my glasses on, I can see good with out them to a point, but to see anything really close, I need to use a magnifier. I keep a nice one right on the work bench to check things before and after a cut.

 

[cazclocker]

Thanks guys, I plan on picking up a couple of sets (fractional and numbered) of 135-degree split-point cobalt steel bits from Amazon.com. The sets I'm looking at are here: fractional and numbered.

Is a pilot drill different from a center drill? I actually have (and rarely use) a few center drills, number 00 and 0 (they're for my watchmaker's lathe, remember). I use them for creating a place to mount the tailstock center when I turn on centers. How does a pilot drill enter into the picture?

 

[bcall2043]

Here is a link to Viking Drill that explains it quite well:

Twist Drill Terminology

Tom

Hi Tom, now I think I'm getting somewhere! That's EXACTLY the kind of stuff I need to read. Thank you very much.

Doug,
I'm with you about the terminology thing. I need pictures to go with the words. I got to reading this great thread and searching and found another good read here: http://www.hssforum.com/DrillingEN.pdf. It covers a lot of drill information and has pictures. Between the link TomG posted and this one is a lot of information about drills.

Glad you asked this question when you did.

Benny
The Orphanage Never Closes

 

[cazclocker]

Doug,
I'm with you about the terminology thing. I need pictures to go with the words. I got to reading this great thread and searching and found another good read here: http://www.hssforum.com/DrillingEN.pdf. It covers a lot of drill information and has pictures. Between the link TomG posted and this one is a lot of information about drills.

Glad you asked this question when you did.

Benny
The Orphanage Never Closes

Benny, thanks for posting that link. EXTREMELY descriptive! Like they say, a picture is worth a thousand words.
...Doug

 

[bcall2043]

I'm getting set to purchase two sets of drill bits....................................Can someone explain the differences in the tip geometries out there with drill bits? Maybe there's a good primer I should purchase and read.

Thanks in advance,
Doug

Doug,
I ran across another article about drill point geometry with pictures. It is very informative and talks about the best point for different materials and the power required to turn them. http://www.mmsonline.com/articles/choose-the-best-drill-point-geometry

May be too late for your purchase decision making process but its never too late to learn this hobby. Plus soon or later you may have to resharpen one for a special application.

Benny
The Orphanage Never Closes