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First experience with solid carbide deep hole drills

gregormarwick

Active member
I've always shied away from buying premium carbide deep hole drills, mainly due to the cost involved and anxiety about just breaking it in the first hole etc.

We machine a lot of 17-4 and suchlike, I've always tended towards simple cobalt drills for deep (16xD, 20xD) holes because it's tried and trusted, if slow.

Since we got our first machine with 1000psi coolant I've gotten a bit bolder about such things, and my confidence has been boosted by some successes with gun drills, which are also a fairly new thing to me.

I have a job in, 17-4PH H900, the parts have a 10mm hole 180mm deep. I decided to take the chance and buy a couple of these from WNT.

Followed the instructions to the letter, drill a start hole .02mm bigger than nominal, enter the hole at 200rpm and 1000mm/min, stop 2mm away from the bottom of the pilot hole, turn on the coolant and ramp up the spindle speed, then go. Instructions said TIR at drill tip not to exceed 0.015mm, couldn't quite get there (have to hold it in an ER25 for clearance reasons), but settled at 0.025.

Man, what a painless experience! 45 seconds per hole including slowing down for a cross hole and controlled retract. So easy. I wish I hadn't been so apprehensive about these drills! The cost was soon forgotten when I saw how much time it saved.
 
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Yup those drills are well worth their cost. We use a 10mm Mitsubishi MVS drill in one of our parts to drill to a depth of about 285mm. Haven't heard of this particular company, but I guess they haven't spread into the US market. I've currently got a Guhring rep wanting me to test out their version. The time savings alone is worth their cost as well as added tool life over old school gun drills.

Welcome to the future brother!
 

gregormarwick

Active member
Yup those drills are well worth their cost. We use a 10mm Mitsubishi MVS drill in one of our parts to drill to a depth of about 285mm. Haven't heard of this particular company, but I guess they haven't spread into the US market. I've currently got a Guhring rep wanting me to test out their version. The time savings alone is worth their cost as well as added tool life over old school gun drills.

Welcome to the future brother!

WNT are a brand of Ceratizit, probably the more common name in the US?
 

BRIAN.T

New member
Yup those drills are well worth their cost. We use a 10mm Mitsubishi MVS drill in one of our parts to drill to a depth of about 285mm. Haven't heard of this particular company, but I guess they haven't spread into the US market. I've currently got a Guhring rep wanting me to test out their version. The time savings alone is worth their cost as well as added tool life over old school gun drills.

Welcome to the future brother!

Guhring crushes everything! Well maybe not everything, but everything I've ever used.
 

EmanuelGoldstein

Active member
.... their cost as well as added tool life over old school gun drills.
Over "old school gun drills" ? I have some doubts about that !

Gun-drill-1.jpg
 

White Lightning

New member
I would highly recommend Walter drills. Great performance and awsome customer support. One of the best features is the shank diameters step up in common sizes. Makes tooling up much easier.

Sent from my SM-G960U using Tapatalk
 

Mtndew

Active member
Man, what a painless experience! 45 seconds per hole including slowing down for a cross hole and controlled retract. So easy. I wish I hadn't been so apprehensive about these drills! The cost was soon forgotten when I saw how much time it saved.

Isn't it great when you drill that deep hole?
The first time you hit that button though... .makes your butt pucker up real good.
 

White Lightning

New member
Isn't it great when you drill that deep hole?
The first time you hit that button though... .makes your butt pucker up real good.
My first experience was in pre-hard 420 optical quality blocks for the lenses of the first self driving car.

Nice pucker feeling to hit the button drilling 10+ in deep .562 dia 52rc with cross holes. Worked out awesome. Now its a norm drilling 1/8 dia. 20x deep and walking to the next machine without a concern.

Sent from my SM-G960U using Tapatalk
 

EmanuelGoldstein

Active member
Ok, fine I'll quantify it then, It's faster than when run on 1 machine who's whole purpose is to run only 1 type of tool.
I was trying to point out that none of these are gun drills. A gun drill is a very specific tool, and still kicks ass over the alternatives.

They just cost a fortune, when you count in the machine to drive them.
 

gregormarwick

Active member
I was trying to point out that none of these are gun drills. A gun drill is a very specific tool, and still kicks ass over the alternatives.

They just cost a fortune, when you count in the machine to drive them.

I've been using gun drills a lot lately, and in cases like this they are not the right tool, which is how I ended up here.

They are much slower, they have much lower tool life in materials like this and I have no means to sharpen them, and they don't handle crossholes well.

Gundrills are awesome too, but I'll reserve them for truly deep holes, 40xD+
 

Mike1974

Active member
Meh... wait until you are drilling .008-.012" dia 20x deep... :D Good news though, if they 'crash' no noise or spindle/toolholder problems! ;)
 








 
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