What drill bits do you use in a drill press for >1/2"?

[Goldhawg]

Since my drill bit collection only goes up to 1/2", wondering how to get a bigger hole that I occasionally want. Any recommended drill bits for metal cutting greater than 1/2"?

 

[lilredex]

I have a "Silver & Deming" set that go to 1", but only use them in my lathe. DP's generally go 'way too fast for most metal drilling.

http://www.google.com/products/cata...=X&ei=vHe5T6ySBsL9ggeT7bTaCg&ved=0CHQQ8wIwAw#

 

[mllester]

I use a Cle-Line 9/16 - 1" set that has worked well. Picked it up at Grainger.
http://www.grainger.com/Grainger/CLELINE-SilverDeming-Set-1A050?Pid=search

 

[Jim Johnstone]

Depending on your drill press, either silver and deming bits if you have a standard chuck, or taper shank bits if your drill press has a knock out chuck and a tapered spindle. The issues as others have mentioned is that the average drill press is too fast and doesn't have enough horsepower to slog through metal.

 

[PT Doc]

Used hf silver dimming bits to drill 5/8" in 3/16" wall tubing. I drilled a less than .25" pilot, then less than .50" prior to the 5/8. Drilled at 300 rpm with tapmatic fluid without a problem.

 

[CAOS]

Annular cutters using a Jacobs chuck adaptor. The best way to drill a hole in my opinion. I use a lot of the Hougen brand ones.

 

[metaleltr]

If you foresee much drilling over 1/2" in metal consider a bridgeport. This may sound like overkill, but drill a 3/4" hole in 1/4" steel with a drill press, then do the same on a milling machine. You will never want to go back to the drill press.

 

[Sincitymetalworks]

If you foresee much drilling over 1/2" in metal consider a bridgeport. This may sound like overkill, but drill a 3/4" hole in 1/4" steel with a drill press, then do the same on a milling machine. You will never want to go back to the drill press.

and to add to your answer.. a normal dill press will not run slow enough for these larger bits..

 

[metaleltr]

I have seen a couple old ones that are fairly slow, maybe not technically slow enough however.

 

[Griff93]

Real industrial drill presses are a lot different then your average home owner drill press. I have a 17in craftsman drill press myself. It does not like to drill stuff over 1/2. It will do it but chatter all over the place. It sits in the corner of my bathroom and rarely gets used.

As suggested above, start looking for a mill. They make an awesome drill press. That's really what I use mine for the most. Most mills have a powerfeed on the quill that makes it where you don't have to stand there and hold pressure down on the handle while it drills. They also have an adjustable stop for the quill feed that will keep you from power feeding into the vise or table if you set it up correctly. The stop also disengages the powerfeed. I have bits up to 1 1/2 in that I use regularly. On larger stuff I set it at 80 rpm 0.0015 per revolution feed. I usually get it all setup and going then go do other simple stuff around my shop like clean the floor. I keep an eye on it but I rarely stand right in front of it. Between this and a horizontal bandsaw I've found more time to clean up while my machines are doing the work.

 

[Outlawmws]

Since my drill bit collection only goes up to 1/2", wondering how to get a bigger hole that I occasionally want. Any recommended drill bits for metal cutting greater than 1/2"?

You need to clarify what you mean by "metal"; the required slower speeds vary all over the map, depending on hardness, and type of metals being drilled. Aluminum can be drilled faster that steels and different steels need different feeds and speeds.

and to add to your answer.. a normal dill press will not run slow enough for these larger bits..

What is a "normal" drill press? Most earlier homeowners DP's were designed for wood working mostly, most current presses (and for the past 20-30 years) are often 16 speed, and can go to 200-300 rpm, slow enough for many requirements under 1"


Back to the OP; Getting away from twist drills you can also go with high quality hole saws, but again speeds, feeds, and appropriate lubrication needs to be addressed.

Get yourself a decent drill speed chart (Google images...) for what you are doing and go from there within the slow speed limits of your DP.

 

[djjsr]

From HF. They work pretty good. Not industrial quality.

 

[woody 73]

I can only go as slow as 700rpm on my drill press but one trick I learned was to mount a 1/2 chuck on my wood lathe tailstock; then I can drill as slow as I want.

Another trick I learned was to buy up those old drill bits and resharpen them,by doing so you can buy some larger Dia. bits over 1/2" for not much money.

 

[rsanter]

if your drill press has the option of using the taper shank bits I would use those if you plan to drill metal

for wood I would get some forstner bits

and if you will be drilling parger holes I would look into getting a 3rd pully setup to drop the RPMs

 

[2oolhound]

You may be able to fit a 3/4" chuck to your dp. Not the best solution but cost effective for those occasions you speak of.

 

[A_Pmech]

Drilling metals with large twist drills takes a lot of thrust and torque, something homeowner or light maintenance drill can't provide. For example, a 1" twist drill in mild steel with no pilot hole requires about 2,000 lbs of thrust. A 2" twist drill requires about 7,400lbs of thrust. For making large holes with limited equipment hole saws, annular cutters and "Uni-bit" style drills work best.

Although drilling under power feed is regularly done on Bridgeports, beware that the power down feed gearing on a Series I Bridgeport is not very heavily built. It was meant mainly for boring, not drilling. While there is an overload clutch, if it sticks for any reason the feed gearing tends to pop. Bridgeport provides the following warning in the 1966 manual:

Power feed can be used for drilling with up to 3/8" diameter drills. Use manual feed for drills larger than 3/8".

Overload clutch is set at factory to hold up to 200Lbs. down pressure on quill, which will accommodate drills up to 3/8" diameter in mild tool steel.

On the Series II machine, the power feed is limited to drills 3/4" and smaller with a power feed capable of providing 1,500lbs of down pressure.

 

[doug.j]

Step bits, hole saws, and drillmate broaching cutters are what I use. Greenlee punches are handy too.

 

[m151]

I drilled a 1 inch hole through 1 inch plate for my wood spliter with a quality hole saw. Went slow with lots of oil to keep the heat down and it worked great. And the hole saw is still OK and was way less than a 1" drill.