Is it just me?

[Dr Dave]

Mac tools has a drill bit set with a warranty. Screw and bolt extractors also.

Fastenal has more than one grade of drillsand taps, the China made is junk, we received a pack of 3/16 China bits by mistake, the center of the twist was so thin you could see through sections of the bit, broke instantly.

I have been using a cutting oil in a airisal can , it comes out and is a thick foam, I think it came from Fastenal.

 

[Pa Pa Jack]

Let me ask another question then. I have to drill 3/4 inch holes through a 1 1/4 inch stock. I only have a drill press that doesn't have a really slow speed. I think 300 rpm's is about the lowest. How should I drill them? what is the best type of bit to drill holes that size?

 

[chris42]

If I recall, my rule of thumb I used to run a 1" bit at 400 rpm for 1020 steel. With my more recent experience I run it much slower.

Remember hole saws? Those cheap metal saws that chewed rough holes in wood and had a wooden plug left over, typically stuck in the hole saw? They now make them specifically for cutting metal. Carbide tipped and precision made they are good, sometimes very good. One of those with a magnet base drill (Milwaukee makes good ones) and you would be likely to have some success.

How many holes?

 

[Pa Pa Jack]

I am going to have about 16 holes to drill. I have several others, but they are larger and I will probably have them drilled by a machine shop. I asked today what they would charge, and the fees were absurd. I realize they have set-up time, but I know it doesn't take an hour to set up to drill a hole and they are all the same so one set-up time would take care of all of them.

 

[the old grind]

Pa Pa Jack, mark your holes with a punch & start with a center drill #3 or #4 and spin it to 800-1000rpm. Go deep enough to get a chamfer from the stepped part & back off when it starts to chatter. Pilot with 1/2" at 450-600rpm and drill thru. Finish with the 3/4" at 300 if that's what you have.

If the parts maneuver easily onto your DP's table, do all holes with each tool/op/speed change. Center up part changes by plunging/holding the bit into each hole before starting the spindle, rotating/wiggling the vise/part back-n-forth a tad and clamping it to the table. Relaxing the feed every few secs will break the chips. Pecking, as advised above, will break & clear them at depth. Dab some cutting oil on with a small brush to keep the drill/hole wet as you go. Last but not least, ignore all this if the parts are too big to muscle around, or if only your two arms are available. :2cents:

btw: I'd pop these for you pro bono in a minute on one of the mills, but I doubt either of us would want to pay for shipping.

 

[muddstopper]

For good quality drill bits, I bought a set of Consolidated Toledo Drill of Toledo Ohio. Drill Bit Set 29 pc. Black & Gold Magnum (CTD) Reasonable price and I cant count the holes I have drilled and havent had to sharpen any of the bits as of yet. Havent broke one either and I have had them for several years. Seems like I gave about $80 ( I noticed the link I provided shows a little higher price)for a set that goes from ity bity up to 1/2in. I keep this set hid so nobody else uses them. Kids and buddies have a habit of abuseing the drill press, and my bits. They get to use the cheap stuff.

I just got thru drilling some 1in holes, 3 1/2 in deep in some shaft material. I have found that trying to start a hole with a large dia drill bit really makes the bit want to wander, even when chucked in a lathe. I like to start with a 1/8 bit, easier to stay on center, then step up to 1/4in, 1/2, then 3/4 then 1in. Really have to do a lot of peck drilling when going that deep. Backing the drill out and blowing out the holes with air to remove chips. Failure to do so will result in the chips burning up the drill along the flutes and gualding of the holes

 

[Waynes Wolrd]

Papa Jack
This (from the old grind) is the best answer you will get.
remember go slow. as far as good drill bits. any titanum or Carbide is good if you don't burn them. The Titanum is gold in color and the Carbide is black (some call them high speed or bimetal but that is just a referance). The light crome color is junk (no carbide) and all junk don't come from overseas; some junk is made here in the states now and so quality tools come from overseas. You just have to know what you are buying before you buy and match quality for application and use. I don't think I would try hole saws bits for 1-1/2" thick metal. I recond it deponds on the hardness of the metal. It would surely work on alum buy not pig iron. I speak from 12 years experience of selling drill bits and hole saws of several name brands and several different grades.
Again Go Slow (travel speed & RPM's) and use pilot hole drill bit first with good quality bits and you will reap good benefits.

 

[navy1]

Don't even consider carbon steel drill bits, unless you are only going to drill soft wood. For drilling steel, High Speed (HS) are the beginning point, next cobalt is a good choice, easily sharpened, and tolerates heat better then any carbon steel bit. Your top choice for most difficult drilled steels is tungsten carbide. They cost more, but for tough to drill applications, they are tops. If you do not have a drill speed and feed chart, get one. Learn that the larger the diameter, the slower the spindle speed (RPM). Charts quite often are given away by drill bit makers, certain sellers, and can be found on the net. Don't forget that if drilling tough or hard materials, a quality coolant/lubricant/ cutting oil is needed. Forget about using engine oil. Fastenal is a good supplier, so is McMaster-Carr which has an amazing selection.

 

[sparc]

Oil is always a good addition (it also helps take heat away).

I would use a fluid meant for drilling and tapping such as Rapid-Tap or TapMagic over oil.

Also, the material you are drilling will have a great impact on how well your bit performs. There are twist bits meant for wood and they will disapoint you if used on even aluminum or A36 steel. Your standard twist bit should be able to handle soft steels, but start drilling harder metals (SA516 Gr 70 and many others) and you need to match the bit as well as the speed and feed rate to the material.

 

[sparc]

Let me ask another question then. I have to drill 3/4 inch holes through a 1 1/4 inch stock. I only have a drill press that doesn't have a really slow speed. I think 300 rpm's is about the lowest. How should I drill them? what is the best type of bit to drill holes that size?

What is the piece you are drilling? Can you use a Mag-drill or Hougen drill. If the machine shop price is crazy expensive maybe you can justify getting the mag drill. I bought one at a tool auction a couple years ago for less than $500. Paid for itself on that one job in time savings.