Question on drill bits??

Parttimer · May 13, 2006

I just mounted a 1,000 lb hand crank winch to a long 2" trailer hitch extension, to be able to use it on my truck, tractor, and trailer. I went through alot of drills for just three holes in what looks like 3/8" thick steel. I know alot of them were probably no good to begin with but, when I went through the little container of drill bits from my grand father's old tool box, it went through it like butter. GrandFather is no longer around, so I can not ask him about it, he used to like to school me in these areas, he was a machinist by trade.

Any how, what drill bits do I need to purchase to use in my drill press for future projects? Thick metal like hitch recievers and such. I do not want to buy junk. Any help would be appreciated greatly.

Dave /forums/images/graemlins/smirk.gif

shvl73 · May 13, 2006

If they were just dulling on you, try a Drill Doctor bit sharpener. You can find them at alot of stores and they work real well. The convenience of being able to re-sharpen and finish the job is worth many times the cost.

Parttimer · May 13, 2006

There must be a difference in quality amoung drill bits? I did a search and found a huge range for drill bits, Just want to know what kind people use, that use them regularly. I am willing to pay decent money "IF" it is worth it. I had alot of fun putting together my little project. Looking forward to more.

Dave

Farwell · May 13, 2006

Dave,
There are a lot if different quality bits on the market. I have never tried the titanium coated bits so don't know if they are any good. The are usually sold it sets that are real cheap.
For general use I use drill bits that have the little point on the tip, they are gold colored and I think they are sold by Black and Decker. The little point sets in the center punch mark and holds the drill in line while starting. I do not know how to sharpen the drills with the tip on them, but they work very well for me.
Always use cutting oil, it will increase the life of your drill bits and make drilling much easier.
There may be a possibility that you were trying to drill through metal that had been hardened during the process of being welded. I was a late learner on this, tried to drill a hole in my FEL that was near a weld, my drill bit sat there and did absolutely nothing. Time to drag out the cutting torch or buy a carbide bit the size I needed.
For larger hole sizes in mild steel I use what is called a slug cutter. Mounted in a magnetic drill or drill press I can drill a one inch hole in one inch material in one minute. The hole is very clean.
I am sure that others on TBN have their preferences.
Farwell

cp1969 · May 13, 2006

Drills are ground and coated for specific purposes. A 118 deg point High Speed Steel bit is probably the most common and would be considered general purpose. The points can vary from flat (180 deg) to 90 degree depending upon the material to be drilled. The drill material itself can be HSS, Cobalt, or Carbide, again, depending upon material to be drilled.

The various coatings, Titanium Nitride probably being the most common, reduce power requirements and extend tool life, however, I'll take a good uncoated tool any day over a Chinese spray paint job.

Some vendors that sell good tools are Enco, Beaver, and MSC and McMaster Carr.

redharley · May 13, 2006

I'll 2nd that,good high speed steel bits for general work are easy to resharpen and not overly expensive.Colblt would be the next step up they last a little longer but once dull are harder to resharpen to orginal specs at home.Ths china coated ones as I call them are being sold in hugh boxes of muti bit sets for $40 or less You can keep a box around for that one time use as a quick fix but these Do Not last in my opinion.

Parttimer · May 13, 2006

Farwell, A cutting torch is on my list for Father's day. can't wait to play with that. What cutting oil for drilling?

CP1969, and Redharley, Thanks for the info. I will check these venders out. Sounds like uncoated drills is the way to go for what i want, and to remember how to sharpen them, My Grandfather taught me how like ten years ago. Took notes somewhere. His drill did not seem to have a coating on them, my drill were the titanium coated ones. I guess junk?

Dave

ronjhall · May 13, 2006

Check around your area for a tool supply store near you. Around Southeastern Michigan I use Production Tool Supply. They stock various HSS drill bit types. The link should give you some ideas of what type to buy.
When drilling with a drill press be sure to run the drill at a slow speed. Most drill presses will not run slow enough to drill holes over 1/2" in steel. As already suggested use a cutting oil.

Egon · May 13, 2006

With drill bits you get what you pay for. Buy real good individual ones in the sizes that are most used. Saves a lot over a set that has many sizes that are never used.

Don't overheat the bits and keep them sharp.

Egon /forums/images/graemlins/grin.gif

ronjhall · May 13, 2006

I use a product called Tap Magic Pro Tap. Click Here It can be found at most Tool Supply Stores.

Farwell · May 13, 2006

Dave,
I use a lot of cutting or threading oil so I buy it by the gallon at Ace Hardware or NAPA auto parts store. I use one of the tractor squirt oil cans or a plastic bottle that has a top with a small spigot on it that will close to apply the oil. I have them all over the place. I also use cutting oil on my hacksaw blades when cutting metal.
Farwell

Farwell · May 13, 2006

Ron,
I forgot about Tap Magic. I have never used it but have read that it is very good.
I always have cutting oil around for my tool room lathe and mill so that is what I use for drilling as well.
Farwell

zeuspaul · May 13, 2006

I used to drill a lot of stainless. Cobalt drill bits went through it like butter when other bits just sat there. Now I only buy cobalt drill bits for all of my metal drilling needs and also use them on wood. They cost a lot more but last a lot lot longer and save a lot of time.

Zeuspaul

5030 · May 13, 2006

Ron:

I have gobs of drills around, High speed, TiN coated Steam coated, Aluminum Nitride coated jobber length, long shank and Micro grain tungsten carbide. The Malfords, the Cbn drills will drill armor plate and glass annd are really meant for drilling hardened dies for reclimation. I tend to use a set of cheap Chinese jobber length standard helix twist drills for 90% of what I drill. I used to have a Drill Doctor but gave it away long ago. I much prefer off hand sharpening and relieving the points on a bench grinder. Once you learn how to offhand sharpen sharpening outfits like the Darex Drill Doctor become useless. I do have a Darex end mill sharpener. You are right, most bench drill presses won't turn the slower RPM's necessary for drilling over 1/2". For drilling over 1/2" or using an annular cutter, the vertical mill is the way to go. I have lots of Tap Magic too. Enco sells it for less than Production Tool.

Hib · May 13, 2006

Coolant, coolant and more coolant plus low RPM's, slow feed and you should be able to drill all the holes you'll ever want. Depending on where your drill press sits, you are better off to run water from a garden hose on your work rather than drilling dry. Most manufacturers use a pump recirculating the same coolant (water) with only about a 5% soluble oil mix. The oil is to keep parts and machinery from rusting more than anything. Of course oil is a good thing, but if the material has been hardened, ya better get the torch and save your bits.

cmuncy · May 14, 2006

( I used to drill a lot of stainless. Cobalt drill bits went through it like butter when other bits just sat there. Now I only buy cobalt drill bits for all of my metal drilling needs and also use them on wood. They cost a lot more but last a lot lot longer and save a lot of time.

Zeuspaul )

I second the sue of Cobalt drill bits.

After I saw a mechanic drill a 1/2" hole on a truck frame in what looked liek a few seconds, I bought a set of Mac branded bits, box of 21, for just under $100.00.

Might have been a bit high priced at the time but I am **** glad I did it. Every tiem I drill through a piece of thick steel, it's like " Doh! How come I didn't et a set of these earlier?"

Sometimes you just have to bite the bullet and get the good stuff. /forums/images/graemlins/grin.gif

bobodu · May 14, 2006

Was poking around Harbor Freight the other day and ran across a bag of probably resharpened factory bits of various sizes for something like $3 for 25!!! These puppies are GREAT!!! I'm gonna grab some more next time.I touch them up when they get tired.I just start on the backside of the cutting edge...twisting slowly at first and speed up as I near the actual cutting edge.This ensures a good releif area.I use the flat of the grinder..a no no I know...but I never had a true wheel in my life. /forums/images/graemlins/grin.gif

Parttimer · May 14, 2006

Thanks for all the info. I do remember my grandfather explaining the use of water or oil for cooling in different applications. I remember him explaining that in some cases the oil actually can bind somethings up???? I can not remember. I gues I will try some plain uncoated high speed twist drills, and I will look for a "good"? set of cobalt drills. The drill press is a cheap 12" delta bench top drill press. I have only used it for wood up untill now. I am going to try to find a quality tool store near me and take a visit. What rpms should the drill be turning for optimum cutting?? My drill press does not have variable speeds, goig to look for the manual to confirm, but it was not alot of money so I doubt it.

Another Question, Does anyone use an inexpensive bench top band saw for cutting metal? If so what blade do you use for good results, going to pick that up too.

Thanks guys for all the input, very helpfull. I was getting tired of reading the packages of drill bits and every one of them say they are better than the others, not very helpfull.

There is no replacing experience, and there is alot of experience on this board.

Dave /forums/images/graemlins/laugh.gif

Hib · May 14, 2006

Most of the bench tops run with belt and pulleys. Should be able to change speed by moving the belt "under the hood'. Somewhere in the 700 rpm range would be a good bet. High speed bits are meant for just that....high speed applications. Meaning for use in 1/4 or 3/8 drills without the benefit of variable speed. I agree with what others have said "buy one or two good bits for the job". No need for a lot of cheapies you may never use.

Parttimer · May 14, 2006

Thanks Hib, Lifted the lid for the first time, guess what there is a chart on the inside for the rpms and the pullys. I just figured that it did not have any adjustments. Only used it a couple of times.

Dave