Annular bits VS. standard bits

[SixKnives]

Ok guys and gals,
Typically I reduce the weight of the handle area by drilling 1/4" holes in the tang combined with the 3/16" holes for the pins just like most makers. My issue is that I feel like I'm always going through bits, both the 3/16 and 1/4. I have tried both the "off the shelf" Milwaukee Cobalt variety and a solid carbide bit purchased on line (made in USA). I use Tap Magic however, my drill press's lowest speed is 740RPM. I do a batch of 5-10 knives at a time and the bits are toast after each batch...is that normal, am I doing something wrong. I feel like I'm spend a lot of money on drill bits...lol

Then I came across these annular bits which seem pretty cool, but the smallest bit that I found was a 5/16. Which I guess is fine to replace the 1/4" holes. But I also read somewhere that the annular bits can NOT be used in a normal/regular drill press.....anybody have experience with these, is that true? Obviously, I cant do anything about the 3/16" bits since they are my pins holes, but looking for good options for the weight reduction holes.

 

[danbot]

Do you use coolant when drilling?
I would run a 1/4" drill around 900rpm and use steady but easy pressure and then ease up on the pressure as it breaks through. You should get hundreds of holes out of a good quality HSS drill bit!

 

[shinyedges]

We use a solid carbide drill on a job that gets a bunch of holes put in a stainless plate. 30,000 holes and then we swap the drill out as a precaution.

A good carbide drill with the correct feed and speed should last a LONG time.

 

[SixKnives]

thank guys, so by running the drill at 740rpm instead of 900ish is not good? at least with a 1/4" bit? I always had the thought that "the slower the better". I take it, that's not true...

 

[shinyedges]

thank guys, so by running the drill at 740rpm instead of 900ish is not good? at least with a 1/4" bit? I always had the thought that "the slower the better". I take it, that's not true...

Does the drill press have auto feed?

What's your max rpm? Is the steel hardened already?

Sounds like your getting premature wear. Keeping the right chip load will increase drill life.

What is the exact drill?

 

[danbot]

thank guys, so by running the drill at 740rpm instead of 900ish is not good? at least with a 1/4" bit? I always had the thought that "the slower the better". I take it, that's not true...

Well, I really don't think a couple hundred rpm slower should have the effect that you seem to be getting, but it does cause you to use more pressure on the bit. So, that could be part of it. And do you center punch the hole locations first? If not, you will be causing the drill to wander, and that paired with the increased pressure could be causing premature wear and dulling.

 

[shinyedges]

If he doesn't have Auto feed, he's gonna have to learn what the correct chip looks like when it has the ideal chip load, and maintain that pressure by hand.

I'm spoiled by cnc machines, but we have drill presses too.

 

[danbot]

If he doesn't have Auto feed, he's gonna have to learn what the correct chip looks like when it has the ideal chip load, and maintain that pressure by hand.

I'm spoiled by cnc machines, but we have drill presses too.

Haha! yes, I'm spoiled now too! But back in the day I drilled many, many holes and even without coolant the bits would last quite a long time (better with a spray bottle of coolant though). Then I just resharpen them on the pedestal grinder and drill more!

 

[shinyedges]

Haha! yes, I'm spoiled now too! But back in the day I drilled many, many holes and even without coolant the bits would last quite a long time (better with a spray bottle of coolant though). Then I just resharpen them on the pedestal grinder and drill more!

HSS has it's place, and I know that many before me used it with great success, BUT I avoid it whenever possible lol

Carbide all the way, some cobalt drills can be badass too. I have an osg drill that drills 17.5 ipm on the side of a round (x live head in a 5 axis lathe) with no spot, center, nothing. Accurate as all get out.

Sumo Cham, and Cham dills from iscar are also pretty tough. Armor plate eats drills and endmills, facemills, taps for breakfast if the feed and speed isn't right. And even when it is, it still might eat it for lunch

 

[danbot]

HSS has it's place, and I know that many before me used it with great success, BUT I avoid it whenever possible lol

Carbide all the way, some cobalt drills can be badass too. I have an osg drill that drills 17.5 ipm on the side of a round (x live head in a 5 axis lathe) with no spot, center, nothing. Accurate as all get out.

Sumo Cham, and Cham dills from iscar are also pretty tough. Armor plate eats drills and endmills, facemills, taps for breakfast if the feed and speed isn't right. And even when it is, it still might eat it for lunch

Yes, most solid carbide drills these days are ground with self centering tips. AWESOME invention!

 

[danbot]

I have an osg drill that drills 17.5 ipm on the side of a round (x live head in a 5 axis lathe) with no spot, center, nothing. Accurate as all get out.

The feeds for some of these drills nowadays are incredible! They need to feed that fast so that the chips will stream out of the hole. Too slow and the drill will clog up and melt!
Don't ask me how I know!

 

[shinyedges]

The feeds for some of these drills nowadays are incredible! They need to feed that fast so that the chips will stream out of the hole. Too slow and the drill will clog up and melt!
Don't ask me how I know!

Iscar flew me and our engineer down to their facility in Texas, while there they did a demonstration of their sumo Cham drills they had a brand new hurco milling machine they were using for the demo.

They pushed the drills way past what they should be ran at for the purpose of showing the durability of the drill even in abuse. Funny story, the Iscar rep programming the hurco, crashed it in front of about 35 of us

 

[SixKnives]

yeah I center punch the holes. Ill up the speed and work of the MANUAL feed rate.....not spoiled yet...lol. maybe one day... now, their should be any difference drilling through 3/16" 01 tool steel correct .

 

[danbot]

yeah I center punch the holes. Ill up the speed and work of the MANUAL feed rate.....not spoiled yet...lol. maybe one day... now, their should be any difference drilling through 3/16" 01 tool steel correct .

Should cut like butter!
Also check to see that the drill is running true. Some grit in the spindle taper, or bad chuck jaws could make it run out of true and that could cause undo wear as well.