Drilling steel

[Flux Core joe]

okay i will admit that i have always had a hard time drilling through still i have steel bits a low speed variable 1/2inch drill and water to keep the bit cooler as it goes through also i punch the steel to allow the bit to get a grip does anyone have any advice do i need to sharpen my bits or try new bits? i have dewalts pilot point bits and some older bits not sure if thier for steel or multipurpose. can ya'll help me?

[mikecwik]

you should sharpen them. its not an easy thing to do but who can afford to toss out bits when the get dull? (the pennsylvania department of transportation is one answer, im sure there are more places)

napa has a house brand of cutting and grinding fluid you might want to try instead of plain water (which will work)
it doesnt cost much and you can add water to it if need be.

if you have been dipping your bit into water you dont want to wait till the bit gets super hot, if the bit makes a noise as it hits the water you may be doing more harm than good.

[Flux Core joe]

thank you i was considering a bit sharpener from home depot i believe it was a drill doctor but last i checked they were 100 bucks and i dont drill enough to purchase it but now i may buy one

[ozarkie]

thank you i was considering a bit sharpener from home depot i believe it was a drill doctor but last i checked they were 100 bucks and i dont drill enough to purchase it but now i may buy one

If you can get a Drill Doctor, get one! I put it off for years and finally sprung for one...will never regret it. You don't realize how dull your bits can become until you sharpen them properly then you'll see them cut much, much better.

As for drilling, use a light oil like 3 in 1, or better, as mentioned earlier, use cutting oil (3 in 1 is just easier to come by). You don't use high rpm's on steel like wood. A few hundred rpm will be fine, you can tell by how it cuts.

Metal bits are usually either standard point, for soft metals or split point for harder alloys.

There's a difference in the bit's point angle for metal vs. wood. Metal bits use a "flatter" bit point angle of 135 deg. whereas wood bits have a "steeper" 118 deg. angle. A flat-ended bit such as a milling bit would be 180 deg. for comparison. Metal bits cut by shaving rather than chewing like wood bits. Look at the spiral shavings you sometimes get when using a drill press. I had a couple of nearly identical bit sets, so I sharpened one set at 135 deg. for metal and the other at 118 deg. for wood. I was amazed at how much better the metal point angle bits cut steel. I think most of your off-the-shelf bits are made to sort of bridge the use for wood or metal and might not cut as well as one you sharpen yourself to the proper angle.

[Flux Core joe]

thank you i will look into cutting oil if not i think the sharper bits will help alot more

[urch55]

Drilling a pilot hole always helps. Say maybe 3/16Th's pilot for a 1/2" drill.. Even tho I don't if I use my press but, by a hand drill I would.use plenty of coolant. I use water soluble oil. As mentioned 135 degree angle is good for metal bits but, I also grind a relief on the 'heel' of the bit (backside of cutting edge).

[Blacksmith]

There are a couple of good threads in here on sharpening drill bits with a bench grinder. I have decided to try and at least get good at this (I'll not use the term "master") skill for the same reason I want to become a passable fly fisherman before I pass on. Carefully following the instructions in those threads, particularly practicing the hand movements with the grinder off until i could do them reasonably well has allowed me to sharpen bits as well as the inexpensive (sandpaper drum drill powered) Drill Doctor I own. I can probably get pretty adept before I ruin $100 worth of drill bits, so I'll continue to practice.

[usmcpop]

Drills need to be properly sharpened. You can only get so many holes. Unless you are drilling in something tough, the regular 118 degree "bits" should work fine.

One thing - never just let the drill spin in the hole. It's not an abrasive burr. You must always be feeding and cutting a chip.

[Flux Core joe]

Drills need to be properly sharpened. You can only get so many holes. Unless you are drilling in something tough, the regular 118 degree "bits" should work fine.

One thing - never just let the drill spin in the hole. It's not an abrasive burr. You must always be feeding and cutting a chip.

thank you your the advice

[caldwellcpl]

I got a Drill Dr. off ebay for about $40 with shipping. Best thing I ever bought. It is amazing how easy they are to use and get a bit that cuts correctly. Man does it make a difference.

[Flux Core joe]

I got a Drill Dr. off ebay for about $40 with shipping. Best thing I ever bought. It is amazing how easy they are to use and get a bit that cuts correctly. Man does it make a difference.

i didnt even think of ebay to buy one from thats way cheaper than homedepot thank you

[ozarkie]

If you want some really interesting reading on drill bits, go to the Drill Doctor home page and navigate to the 500X Model.

Click on "Learn More" for info and download some of the pdf files describing the machine and more important, some info on bits, types, etc.

[ct01r]

I agree with all of the above. I bought a Drill Doctor a few years back, and it's worth its weight in gold. I've bought bits at yard sales and flea markets, and probably have 3 - 4 dozen of different sizes that i've sharpen. Some were broken, and they all came out as sharp as new. The only problem I've found with the Drill Doctor is when the bits become too short for the mount. That's when hand grinding would come in handy. At the price I've paid for them though, at that point the bits go in the scrap bin. The only bits that I've bought new in the last 10 years are smaller ones (smaller than 1/8th inch). These are usually too small for the Drill Doctor, but cheap enough. I also agree with using oil, not water, and that it doesn't matter what kind of oil for the average user. I've used 3 in 1 oil, 20 wgt machine oil, motor oil, sewing machine oil, etc. wtihout noticing a difference. The oil will give you cooling as well as lubricating, and will keep your bits sharp longer than the water will. Cutting oil will give you the advantage of flexibility. You can use one cutting oil on different material. I was always told to use water on stainless, oil on steel, and something else on brass (don't remember what that was, it was too long ago!). Cutting oil should be usable on multiple material. If you can't find it locally, try the internet. Sorry this is so long-winded! Curt

[aametalmaster]

okay i will admit that i have always had a hard time drilling through still i have steel bits a low speed variable 1/2inch drill

That is another problem. You need 2 drills. One like you have for the bigger holes and another faster rpm drill for the small holes. Take a 1/8" bit and the 2 different drills and see which one drills thru first. I see guys all day fighting 1/4" holes with a 1/2" drill. Just my thoughts...Bob

[urch55]

That is another problem. You need 2 drills. One like you have for the bigger holes and another faster rpm drill for the small holes. Take a 1/8" bit and the 2 different drills and see which one drills thru first. I see guys all day fighting 1/4" holes with a 1/2" drill. Just my thoughts...Bob

I agree with you 110% Bob.
I use a faster 3/8" drill for just about any thing smaller than 3/8". I also like drilling pilot holes when I drill by hand...