Recommend a metalworking book?

Sat, Feb 4, 2006, 3:29pm (EST-3) snipped-for-privacy@yahoo.com (MB) mumbles: Can anyone recommend a basic metalworking book

Basic. You want info on wood, you come here. You want info on metal, you best check with a metal newsgroup.

JOAT Have a nice day! Someplace else.

Get yourself a "Drill Doctor" unit to resharpen your twist bits.

The rec.crafts.metalworking group will amaze you with how complex an issue drilling a hole can be to a machinist. Warning: their toys can be

J.

MB wrote:

| I recently drilled some holes in the cast iron top of my saw to | install a new fence. When I was done, the tip of the drill bit was | too dull to drill soft pine. (When I first tried using the bit on | wood, I thought the drill was running in reverse).

You were probably running the drill much too fast and not using coolant...

| Anyway, I figured that that with a little metal working knowledge I | might be able to drill more than four holes before completely | dulling a bit. Maybe it was the wrong type of bit? (It was from a | dewalt set with a yellow/gold coating).

If it was a twist drill, you were at least fairly close.

| Can anyone recommend a basic metalworking book so I could read up on | the right technique for this a future metalworking endeavors?. | Hopefully it will include a chapter on sharpening drill bits too.

Try news:rec.crafts.metalworking (you might first do a Google group search and read the previous answers to the question before you ask it again) and your local library.

-- Morris Dovey DeSoto Solar DeSoto, Iowa USA

On 4 Feb 2006 15:29:29 -0800, with neither quill nor qualm, "MB" quickly quoth:

Here's a speed chart.

Also ask over on the rec.crafts.metalworking newsgroup. There are guys there with 'bout 100 years of experience. (Right, Andy?)

Sharpening almost all woodworking tools: Leonard Lee's book:

--------------------------------------------------- I drive way too fast to worry about my cholesterol. ---------------------------------------------------

I'm no metalworker, but I've had the same problem. Seems to me, every machine shop I've ever seen uses plenty of water and coolant sprayed on the cutter. When drilling metal I've found it quite beneficial to use a sharp drill and either run a small stream of water where the bit meets the metal, or find a way to pool the water at the drilling location. It would appear that metal cutting metal generates an awful lot of heat... enough to heat up the sharp edge of a drill bit and temper it's hardness.... thus making it duller... thus generating more heat... etc.

Like I said, I'm no machinist, but those have been my experiences and keeping a sharp bit doused in water helps an awful lot.

Joe Barta

There is no such thing as to slow. To fast is a different story. The speeds listed in the link are WAY to fast and will guarantee a burned up drill bit. Cast iron drills quite nicely with the proper technique. Drilling by hand with a drill motor in metal is quite hard on a drill bit. It cannot be fed fast enough for an efficient cut. It does a lot of scraping rather than cutting. This dulls the point rapidly.

There are a bunch of GREAT web sites which cost less than the book... But it sounds like you ran too high an RPM. See the following next time...

No coolant is needed on Cast Iron if you run it at approxmately 75% or less of the maximum suggested RPM...

Again, see

LOL...

Heck... e-mail me and I'll do the research for you... Just don't use that first chart!

Cast Iron is actually one of the easier metals to drill because it "flakes" out rather than creating sticky chips...

I wood terms... Cast Iron is to Oak as Aluminum is to Sappy Pine...

Yup. Good advice.

grabbing the workpiece?

er

If only they wouldn't incessantly natter off-topic. They make this group look positively *focused*!

;-o

er

On Mon, 06 Feb 2006 15:52:35 -0800, with neither quill nor qualm, Enoch Root quickly quoth:

Yeah, I'm hitting the (I)gnore key quite often there, too. Believe it or not, there's even an OT topic discussing how many fewer spams they're receiving lately.

Thanks Joe for posting a realistic speed chart. That other one has been around a while and makes me wonder how many drills have died due to it.

| See the following next time... | |

Bookmarked. S'bout time. :-)

Thanks!

-- Morris Dovey DeSoto Solar DeSoto, Iowa USA

Hoping as in wishing for good results?

Bottom line is that it generally works like aluminum unless you are working with an machine such as CNC that maximizes thrust, RPM, etc. Not exactly like aluminum of course, but close enough that for the general purpose end user, the speeds posted should work just fine.

...It is almost always necessary to use some sort of lubricant with aluminum though as it sticks in the flutes real bad once the bit is hot... Might be the same problem with brass or some bronze alloys depending on how aggressive you are. Alumibronze is usually okay because it is hard but I don't have too much experience with the real soft stuff.

My experience is rather limited, but says the bit edge digs in to the brass far more readily than it does in aluminum.

There are special bits for brass, though, (less rake to the edge) that are supposed to mitigate this.

er

You are correct in saying that there are special tools offered for this... However, a single set of High Speed Steel (HSS) bits will work on just about any metal you need to drill including the infamous Stainless Steel. The key is to always run slower than the charts say and use coolant whenever possible. Stainless can NOT be drilled without coolant unless you spiun the bit at insanely low RPM rates. Of course, there are people who need to run at the maximum possible RPM rate. They use Cobalt coated tooling, carbide tooling, lots of specialized coolant, etc.

If anyone has a question as to what speed they need to run when drillign metal, just shoot me an e-mail. It is part of what I do all day long for my customers... A 10 second answer will not kill me and will probably save you from buying a new tool.

In return, I'll ask all sorts of random and funky wood and wood-related questions from time to time. :)

Regards, Joe Agro, Jr. (800) 871-5022 (908) 542-0244 Automatic / Pneumatic Drills: