Drill bit points, angles, etc

[Dan_F]

Just got as Drill DR, wondering what people prefer as far as the point angle (118* or 135*), and whether standard point or split point. Is there a difference in the above when you drill acrylics as opposed to wood? Thanks

Dan

 

[n7blw]

I've used the standard 118 degree grind so far, but would like to hear what the machinists have to say. I do grind a split point on all the bits I use for drilling my blanks. I think it helps minimize bit wander in the hole. I have an XPK Drill Doctor that came with a 3/4 inch collet.

 

[rherrell]

I use 118 degree bits and they work just fine FOR ME. You'll hear alot about "bit wander" on this topic but I've found that if you keep your bits sharp, and use a SOLID method to hold your blank, then bit wander is a non issue no matter how you sharpen your bits.

 

[JohnU]

I agree. I also use 118 and drill slow, backing out a little each time to clear the path and keep down the friction.

 

[Rifleman1776]

I use the split point simply because the option was there when I got my DD and they work just fine. No reason to stop using it.

 

[rlharding]

I had no idea that there are angles that need/could be considered. I just go to the store and get a split version of whatever I need.

 

[Tea Clipper]

I bought the standard 115pc set from HF. I converted one of the bits to split point as a trial to to see how I liked it. Either way, just using the drill doctor made a huge improvement, however the split point seemed to cut a little better for me. I now convert to split point whenever a bit needs sharpening. HF also sells the 115pc set in split point, so I would recommend buying that set if someone is in the market for drill bits.

 

[Dan_F]

Thanks to all for the repiles!

Dan

 

[bitshird]

135 degree drill bits are normally for hard metals, There are 118 degree drill bits designed for use in Aluminum that evacuate waste/chips quicker due to a high helix, they work very well on plastics/acrylics and wood, I still won't drill all the way through acrylics, but these drills eat acrylic so fast it doesn't have a chance to get hot, they also work very well for hard woods, stuff like Ipe, Maca Jatoba and wood that likes to split and blow out. Enco carries these bits in nearly any size you need,
I've never used any thing like a Drill Doctor, but I've heard they work very well; it's just that as a Machinist/Instructor, I would be subject to ridicule. But as I tell students if it works for you and does the job use it. They still have to learn to sharpen drills by hand and do split points as well.[}]