More About Drill Bits

Moonlite37

Well-known Member
Rather than to add to the post about reduced shank bits. There was some mention of the poor performance of low priced reduced shank bits. This is partially due to the higher speeds of the more common drill presses. Most low priced drill presses run about right for the largest size bit that matches size of the shank to the lowest speed of the. drill press. I have a set of imported (China) bits to 1" with reduced shank. My common drill press (also possibly china)with a maximum 5/8 chuck runs faster than the proper speed for a 1"it. therefore I have to use caution with the larger bits. I am pleased with my Chinese bits but they will not take the abuse of excessive speed the genuine Morse or Greenfield bits may take. I do not know if the higher quality bits are made in reduced shank sizes, but I assume if the user can justify the cost of high quality bits. he may also have a better drill press with more speed selections and a Morse taper socket
 
You can get higher quality bits with reduced shank, and you get what you pay for! Industry standard is 1/2" on the shank, most have the 3 flats for the chuck jaws to hold on to.

You are right about the drill press running too fast. Those are designed for wood working mainly.

There is also a drill press with double reduction pulleys that will get down to a good metal working speed. It is a simple set up, a step pulley in between the motor and spindle that allows for a much wider RPM selection. They are slightly higher, but well worth the expense if doing metal work.
 
The real problem with the China-made drill presses is that they don't have the torque to push larger drills. You need to start small and step the hole up to the final size. 1/8 at a time but keep the speed slower to keep from burning up the edges and feed lightly to keep it from screwing in to softer materials.
 
I've long considered my HF set of S&D bits one of my best investments. They run 9/16 to 1" by 1/8", cost less than $20 when I bought them more than a decade ago and I've drilled thousands of holes with them. My "big" drill press is a China-made floor one with triple step pulleys, and though even at its lowest setting it's not quite slow enough for optimal drilling of large holes in steel it works fine once you understand its limitations. Slow speed, firm pressure, rigid setup, lots of cutting fluid, step drilling and some patience will let you drill just fine in most cases. The only bit I've ruined was the 9/16 one, and that was not the drill's fault--a clamp came loose and allowed the workpiece to tilt while the bit was deep in a hole, which twisted the drill shank before I could shut the press down. My latest project was helping a friend build a chicken plucker, which involved, among a number of other things, drilling 80+ holes of 3/4" diameter in a piece of 5/16" steel for mounting the rubber plucking "fingers". Used the drill press for what we could reach and my old gear-reduction hand-held electric one for the ones in the center of the plate that the throat of the drill press couldn't reach, and the HF bits held up just fine.
 
Just walked out to the garage to get an actual number from my drill press--it's a 16-speed with a nominal lowest speed of 195 RPM. That's within the ballpark of acceptable speeds for 1" drills in mild steel, though as noted the limiting factor is more often the available torque than the speed--I'll usually get stalling, belt slippage, or other troubles if I try to take too much material at once. Also, to correct a finger stutter in my first post, my S&D set is an 8-piece one that runs from 9/16" to 1" in 1/16" increments, which is the usual set you'll see at any of the discount tool sellers, though I notice they've crept up considerably in price--HF's is now listed at around 35 bucks, subject, of course, to their usual "sales", coupons, etc.
HF silver and deming drill bit set
 

OK, I walked out to my shop.
My floor drill press is a Delta 14-070,
12 speed 3 step pulleys,
250 to 3000 rpm,
I have a set of reduced shank, w/3 flats, 17/32 to 1"
I have a Drill Doctor, w/2 chucks will sharpen up to 11/17
I don't wait for a bit to get dull I touch them up every so often.

It came with a master switch. I added a work light to the drill press. I also added a foot switch to it, and wired it so the foot switch is only active when the master switch is on, the light is also on when the master switch is on.

I also added a compound slide to it, and a drill press vice to the slide.
I often put a board in the vice and drill free hand. I really like the foot switch when drilling free hand.

I find it somewhat of a pain moving the belts around to change speeds.
A variable speed motor would be nice,but I don't have 3 phase, and I would think that it would it have rather low hp. when turning slow.
 

I also have a S&D set from half to an inch by 32nds. About $70 ten or so years ago. Best money I ever spent.
I've got a floor model Taiwan drill press with a number 2 Morse taper spindle.
One thing I did, was put a 1/2 hp farm duty motor on it. Those style motors have lots of torque and reversible setup's in them. On mine, and I think on most of them, you switch wires 5 and 8 to change direction. I pulled those wires off their terminals and ran them to a triple pole, triple throw switch, wired an X across poles and then ran them back to terminals on the circuit board. My drill will now run forward and backwards with the flip of a switch. If the drill sticks, I shut it off, put it in reverse and back out it comes. And it also makes a wonderful tapper. Ya gotta be quick on the switch, but I've done many holes with it. The best part, is your tap is lined up straight with the hole, and thats the hardest part to do by hand.


Irv
 

I also have a S&D set from half to an inch by 32nds. About $70 ten or so years ago. Best money I ever spent.
I've got a floor model Taiwan drill press with a number 2 Morse taper spindle.
One thing I did, was put a 1/2 hp farm duty motor on it. Those style motors have lots of torque and reversible setup's in them. On mine, and I think on most of them, you switch wires 5 and 8 to change direction. I pulled those wires off their terminals and ran them to a triple pole, triple throw switch, wired an X across poles and then ran them back to terminals on the circuit board. My drill will now run forward and backwards with the flip of a switch. If the drill sticks, I shut it off, put it in reverse and back out it comes. And it also makes a wonderful tapper. Ya gotta be quick on the switch, but I've done many holes with it. The best part, is your tap is lined up straight with the hole, and thats the hardest part to do by hand.


Irv
 

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