Some Thoughts on Basic Metal Working - Part 2 (Hand Tools)

I've always wanted an English wheel

AND a Forging Hammer!

 

After many years of using cheep Black Oxide drill bits I finally started using titanium. But titanium is a coating like paint and does not last very long. .. A few years ago I discovered cobalt drills.

.Its like night and day.

WELL worth the extra money.



“Different types of drill bits are used to cut holes in different types of materials. Diamond drill bits are used for materials such as glass and tile; black oxide bits are common for plastics and carbon. Cobalt drill bits are particularly successful in cutting through hard metals such as stainless steel and cast iron,

although they can be used for softer materials, too.

Cobalt drill bits are not made of pure cobalt, but rather a steel alloy with 5 to 8 percent cobalt. The 5-percent alloy is known as M35 grade, and the 8-percent alloy is M42. The cobalt increases the strength of the steel and makes it more heat-resistant; this is an important factor in drilling hard materials because the friction of metal against metal can produce high temperatures that damage the material or the drill bit. Bosch, for instance, makes a cobalt drill bit that can withstand temperatures of up to 1,100 degrees Fahrenheit (593 degrees Celsius).

New cobalt drill bits are a dull gold color, making them distinctive on the shelf (or in your toolbox). The color occurs when the drill bits are baked in the process of production; it’s not a paint or plating -- cobalt drill bits are cobalt alloy through and through. For this reason, they can be sharpened relatively easily with cutting fluid while retaining their strength and durability (although the gold color may wear off).

Cobalt drill bits are often more expensive than other drill bits, but if you regularly drill through metal, they are a good investment since they tend to last longer. You can buy sets of drill bits in graduated sizes or individual drill bits for your specific needs.”

 

I did some work in the shop this weekend and had to do some drilling in tough material (drilling out broken bolts). This ate up a few drill bits so when that project was done, I sat in a chair, drank some nice porter beer and sharpened a bunch of drill bits. Then it occurred to me I don’t think I had advocated this little toy for people, the Drill Doctor.



This is a wonderful product. I have the DD750X which will sharpen twist drill bits up to 3/4 inch diameter (hence the 750 like .75 in the name). There is a bit cheaper model that is the DD500X that will sharpen up to 1/2 inch bits. There is also a model half the price of the 500 but it is limited in its capacity but if one doesn’t do much drilling, it may be adequate.

I personally recommend the 500 or 750 machines as they possess more flexibility. These can sharpen 118 degree drills (the normal) and also 135 degree pointed drill bits and they will sharpen or create split point drills. Split points are nice and tend to drill through stuff more easily if you haven’t drilled a pilot hole first. A conventional bit is on the left and the split point on the right. The key is the web area in the middle is cut down so the bit penetrates into the material a bit easier. Split points also don't wander near as much when starting a new hole.



Overall the machine is a bit loud and noisy and given that for the most part it is plastic, it seems questionable as to it capability. However, the critical plastic parts are glass filled engineering plastics and very stable. You will note the reviews on Amazon are very high and it is a solid product.

I have had my Drill Doctor for about 4 years and really like it. Super easy to use and not hard to learn. I re-sharpen bits over and over and have saved a fortune not buying new ones. One of the best parts, is if I dull or break a bit in the middle of a project, can just re-sharpen in a couple minutes and get right back at it. No trips to hardware or big box store for a replacement. This could also be quite valuable for a time when going to a store for a new bit is no longer an option.

I do recommend getting a couple additional diamond grinding wheels for it. The standard grit wheel is 160 and is fine for 3/16 up to 3/8 inch bits but for the smaller bits I kind of like a finer 220 grit wheel and for the bigger bits a courser grit saves a fair amount of time. For my biggest bits I will sharpen multiple bits with the course grit (I think its 100) then come back and touch them all up will a finer grit to get a cleaner cutting edge. Not hard to change out the grinding wheel either.

Drill Doctor

http://www.amazon.com/Drill-Doctor-DD750X-Bit-Sharpener/dp/B000BKTA00/ref=sr_1_1?s=hi&ie=UTF8&qid=1430257043&sr=1-1&keywords=drill+doctor

http://www.amazon.com/Drill-Doctor-32-Inch-2-Inch-Sharpener/dp/B000BKUY1O/ref=sr_1_3?s=hi&ie=UTF8&qid=1430257043&sr=1-3&keywords=drill+doctor

http://www.amazon.com/Drill-Doctor-DD350X-Bit-Sharpener/dp/B000BKX9CU/ref=sr_1_2?s=hi&ie=UTF8&qid=1430257043&sr=1-2&keywords=drill+doctor

Have Fun.
AT

 

I have used them, and they are great little machines, although honestly, I don't have one here. I was taught to sharpen bits using a drill point gauge and have a bench grinder set up just for that.

 

I'm glad SOMEONE can do it right. We hired a guy to resharpen all the company's drill bits, and not one of them would drill a hole in mashed taters!
He too had a drill doctor good for up to half inch, though I don't know what model, but it was a complete write off for us.
If I do get one, I will contact you then for lessons, if you don't mind....

 

Used one on the crane truck for a jobs last year. Had to cut though welds in poles for new light fixtures, burned though a bit every other pole. Sharpener saved a ton of money and time.

 

I learned (read a book and self taught) how to sharpen by hand as well. I too have a fixture I got 40 years ago for mounting on a bench grinder. It's very good to know hand sharpening and metal workers should learn, if for no other reason but to recognize a properly sharpened bit.

Unfortunately, with hand sharpened bits, if you don't get the intersection of the cutting lips right in the middle of the web with the two cutting lips being exactly the same length, then the bit will tend to drill a larger diameter hole. When doing precision holes for tapping, etc. just 5-10 thousandths off can be significant and it is tedious getting super accurate with drill gages and calipers. The Doctor gets us a thousandth, maybe less, and I dont have to hardly think about it. I can drink beer and sharpen 3 dozen bits in less than an hour, including the split points. I like that.

AT

 

i am looking for a magnetic drill press. for my "home shop". does anyone have any suggested brands?

 

Milwaukee is solid and last for years. They have a number of models and that brings us to the question of what are your plans and expectations?

These things are not cheap and their functionality can vary a good amount. For example, are you planning to stick it to vertical things or even overhead to drill holes? If so you probably want something that weighs less than most Milwaukees, maybe a smaller Jancy.

How precise does hole location need to be? You may want one that has adjustments that allow you to move the spindle left or right and fore or aft a bit after the magnet engages the work to get more accurate hole location.

How big of holes and material? Would you benefit from one with a Morse taper spindle? Are you going to use hole saws for larger diameter holes? If so, you might want one with a gear box to cut spindle speed way down. You need to also consider magnetic grip strength. Do you need lower amperage draw (genset operation) with a permanent magnet base or electromagnetic base to handle the hole saw torques?

If you are just using it on a welding table or similar and just vertically drilling modest sized holes with twist drill bits, a basic Milwaukee would be more than adequate and will last you a lifetime. More than that, you need to look at the weight and features. That said, I have only used Milwaukee and Jancy and these were well used and still solid machines. Can't offer any insite on others like P&C, Fein, Hilti, Hougen, Dewalt, etc.

AT

 

Airtime pretty well nailed it and I agree 100%. The Jancy is lighter and personally I like it better for slugger bits.

 

Great metal working threads by the way!!

anybody interested in tinsmithing?

just starting to get my mind into it after watching this vid..



very minimal tools

 

Some very important tools are essential are the PPEs
Personal Protection Equipment
face shield/safety glasses.
When you know that you will be making chips and sparks, the face shield is best.
A hat is not a bad idea either.
Safety glasses should be as natural wearing as putting on shoes.
Gloves appropriate to the task. especially grinding ,be it a bench grinder or disk hand held grinder, good fitting leather gloves give the best protection, and don't easily burn.
Synthetic gloves can be a night mare if the catch fire or melt.
Using solvents requires latex or equivalent . solvents penetrate the skin .
Shoes that will resist sparks and debris leather steel toe work boots are best.
I have often employed the use of my feet to move or lift something large and or a sheet of steel .
no jewelry or loose clothing.
More than a few have been pulled into machinery or lost fingers.
If you find your self being hurried, STOP ..
ANY grinding device can potentially throw it's self apart ,assume this to be so and treat it thusly.
On the hack saw , remember it only cuts in one direction, drawing it back dragging the teeth rolls them over. Make your strokes smooth and deliberate, and lift the tool drawing it back.
There are different tooth counts for varrying hardness of steel.
Cutting coolants should be employed every time one is cutting steel . (cutting "oil" is a misnomer you are not lubricating .
The effort is to keep the tool and the material cool) In some cases (stainless) alcohol is better. Slow is better than fast.
Each metal has a preferred coolant.

 

Each metalworker has their preferred coolant.....my preferred coolant is beer....chilled to just above freezing.

Edit: best consumed after the metal crafting is done....tankards are difficult to hold with missing fingers and thumbs.

 

Ditto most of the PPE comments.
However, glove wear requires important consideration. Yes, they are important and can prevent injury and even just small booboos. However, there are times glove wear is dangerous. Don't wear them around an operating lathe. Depending on the glove, generally do not wear them around a mill or drill press while actually cutting (during set up can be good.) If the back of the glove brushes the rotating bit while reaching to brush more cutting oil on the bit, the glove can wrap right up on the bit badly injuring a hand. Stationary belt sanders have a similar problem and can be more dangerous with gloves. Even bench grinders can grab a glove and suck in a hand depending how the rest is set relative to the wheel. I will wear gloves with a buffer or wire wheel (no steady rest against which a glove can be grabbed) or even an angle grinder but generally not with a bench grinder. A small 1st degree burn or a little skin loss is peanuts compared to a glove sucking in grinding away skin, ligaments and tendons down to the bone. The common factor in these examples is the glove can snag on the rotating tool bits, moving belts or work and drag your hand further into the trouble.

 

Witnessed a construction worker that allowed an electric hand drill that was running get to close to his leg.. The drill bit grabbed his jean leg and ripped it up into a ball putting a pretty good laceration in his leg.. The spinning drill beat the crap out of him as well once the handle ripped out of his hand..

 

And I saw a newbie, wearing leather gloves while running a tables away, get caught in the blade. Not pretty. They were able of reattach the four fingers removed, and they expected him to regain about 70% of the use of his hand.
I never did hear if he met that mark or not, as I never saw him on the job again.
(Thankfully, he was not with one of our crews)

 

Appropriate Proper fitting gloves generally do not create problems ,loose fitting clothing is never acceptable in an environment with rotating equipment .
Sloppy fitting gloves mean that the wearer cannot feel what he is doing till the loose portion of the fabric is made contact with the finger. The is a serious problem.
Some times latex gloves are better then nothing, so long as they fit well.
Working on machinery it's not easy to wear latex with out it tearing however they have never posed a threat .
They are not heat resistant like leather, but beat bare skin when dealing with chemicals and in the event your sporting a cut already can help to keep the area cleaner than without some coverage.
I don't always wear gloves ,but I do driving ,both bike and auto for several reasons .
I've landed on the asphalt a time or two ,my hands were spared, that's important.
In the event of an emergency having the gloves on while driving gives me the advantage.
In the event of an accident with torn sheet metal and broken glass every where.
I don't plan on having an accident but I don't want to be disarmed in any event.
Having been in S&R the biggest mistake is coming to a call out, unprepared .
One movie emphasized this diligence failure "Castaway" Tom hanks took his shoes off on the plane in flight.
You don't know when disaster is going to strike .

 

Speaking of stainless steel, this 'ol dog just learned a new trick:
Use Elmers glue as a lube on your drill bit when drilling SS.

I was told this last week by a maint. guy I'm doing a project for. I kinda raised my eyebrows, but got a bottle and tried it. It friggin works like a dream. I can't begin to explain why, but it makes drilling SS just like mild steel. I've had to drill a bunch of holes (5/16ths and 3/8") through 10 gauge and 1/4" for this job, and after a week I've sharpened the bits once.

 

Again , you are not lubricating the cut , you need to cool the tool and the work piece.
Much like the bow drill the friction built up heats up both parts ,,and in the case of the drill bit, it will remove it's temper and the work surface harden it . Once this happens the drill bit will either have to be replaced or sharpened past the lost temper with out doing it again on the grinder. that work surface will need to be brought to temp and very slowly cooled to remove it's temper.
Cutting steel/metal will make it hot, no matter how it's done .if that heat transfers to the tool it will loose it's temper..
with one exception,
There is a system for drilling that uses this friction to melt the work piece and the drill bit has a heat sink for powerfully drawing off the heat from the tool. Flowdrill
The big advantage to this system is that in sheet metals the melted material remains and there is no debris and , it adds to the strength of the material rather than creating a weak point .They also have a tapping system that works on the same principles.
It requires a strong drill press that is reversible ,and is very cost effective in production environments.
If I were to go into production o some of my inventions this is the system I would use.

 

Actually, cutting fluid does provide lubrication for the bit in the hole and especially for the chips to clear the cutting edge. A pretty high flow rate of fluid is needed to provide much direct cooling. Running high flow coolant on a lathe, drill press, mill, band saw, etc. is done mostly to permit more aggressive material removal as desired in production environents. Yes, some drills loose their edge if they get too hot. High speed steel on the other hand can be heated to well over 1000 deg F without a significant compromise to it's cutting ability. It is very possible to get temperatures due to friction higher than 1000-1100 F and this is where cutting fluids can really help, they can significantly reduce friction (heat generation) both between bit and hole walls and more importantly between the chips, the bit and the hole walls. Fluids and oils might help cooling through improving the conduction of heat from the bit into the material being machined but I wouldn't hang my hat on that being a huge contributor.

Tully, I know you have drilled tens of thousands of holes in your years of fabrication work. If you were amazed, then I'll need to try it. Personally, I generally use TapMagic (the old formula was better the the new stuff) on steel, iron, stainless, etc. on my mills, lathe or drill presses. I don't generally lubricate or bother with the flood coolant on the band saw. For aluminum I have found just plain ole WD-40 works adequately well.

I'll play with this but my initial guess as to the performance is the viscosity and maybe adhesion helps keep it near the tip and facilitates chip clearing. If the chips don't move away from the bottom of the cut, the bit can ride up on them as the next edge comes around and this really slows material removal. Compare chip thicknesses, color, length and width when drilling with and without the Elmer's. Let's us know what you notice.

AT