thingmaker3

My spectacular wife let me buy a 10F for my birthday this week!

My rocker is roughly 1.8" long, and 0.375" wide. The thickest part is 0.27, give or take, and the ends are 0.115" and 0.10" thick.

The straight side is textured. Looks like a sort of inverse honeycomb - raised round dots on a hexagonal grid. They stand out maybe 5 mils? They're on perhaps 0.1" centers. I suspect one could grind down an old wood rasp to get this same gripper effect.

The more securely you fasten it, the easier it will be to smuush the steel. I can't think of any reason why some holes might be bad. They certaily would let you use some timberlock screws to attach to a stump.

Figure out the sq inches then multiply bt 120? 120psi is 120lbs per sq inch last time I checked.

Yes. Now multiply by each and every square inch for the total force. That's what the "per square inch" means. ;)

Rheostats are fine for "universal" motors (aka AC-DC motors), but not good for shaded-pole induction motors. Induction motors have to have both the power AND the frequency changed - ergo we use the VFDs for induction motors. Rheostats can "work" for induction motors over a narrow range, but don't expect the motor to last as long as it should.

Also, by "rheostat" I'm assuming we mean "autotransformer" and not "potentiometer." Potentiometers (aka variable resistors) are seldom made big enough to handle anything but the smallest universal motors.

The original question on soaking was related to drawing not austenizing.

It was? Golly. I read it as dunking the chisel in anti-sieze between whacks while in use.

Don't they spray down H13 dies with water in industrial use? (That's "use," not "HT.") Or is that something other than water?

Carbon diffuses realatively quickly through iron because carbon atoms are timy compared to iron atoms. Ditto for boron.

Not so for chromium or vanadium or other "big" atoms.

Note well: adding chromium or other elements WILL NOT increase hardness. Hardenability, yes, but not hardness. Maximum attainable hardness is is related to carbon content. Again, its those tiny atoms in amongst the bigger ones which do our trick for us.

Robert, what is it you want to make? Why the requirement for rust-resistance?

Computer glitch. Please disregard post

How about making a punch & die with profile in the shape of a tiny key? Then hot-punch out of 16 or 14 gage strip under a power hammer.

I've seen threads hijacked before but this is one is a topper.

Topper for jalepeno & avocado ice cream? I'd try sour cream & pico de gallo. Serve it up in a cone folded from a nice corn tortilla.

As for soaking H13 or other high-alloy steels, the carbides need some time to dissolve into the austenite. Soak times listed on the data sheets are per inch. So if we've got a 3/16" thick slitting punch at 20-30 minutes per inch, we leave it at temp for 4 or 5 minutes.

The burners will work rightside up, upside down, or any angle in between. Static pressure is static pressure, it is equal in all directions within any subsystem. You don't get a gust of wind upward into your attic do you? A gale going up the stairs from the basement?

As for "heat rising," well, that's a common misunderstanding. Cold air displaces hot air resulting in hot air baloons rising. Heat will move from where there is more heat to where there is less heat. (Unless forced to do otherwise.)

Any boyancy of the flame is negligable compared to the pressure in the flare or tube.

I hope this eliminates more confusion than it causes.

My wife trims my chin-hair eight times a year, whether it needs it or not.

Another detail worth noting is we're talking about plain-carbon and low-alloy steels in this thread. Just stuffing a hot piece of S7 or A2 in ashes overnight will not anneal it. Just stuffing a hot piece of 1045 in ashes overnight will.

It has to do with how fast the carbon can move through those crystals to collect into carbides. Any good metallurgy text available through your library system will help with understanding.

(I also have a copy of the 1947 handbook)

'Tis a rare day indeed when I can trumph Master Thomas. I've got a copy of the 1939 edition (free from a buddy's dad's stash), several volumes of the 8th edition, and I recently scored one volume of the 9th for FIVE BUCKS.

Of course, he still has more books than me overall.

Anyway, one can find volumes of the 8th edition for $25 or less if one scrounges around. Excellent stuff!

Data sheet for this steel says to forge at 1050C and not to forge below 840C. Was this adhered to?

See also:

Tool Steel Simplified by Palmer and Leursen

Principles of Heat Treatment of Steel by George Krauss

Kingdom of Heaven? Ain't that the one where Orlando Bloom dunks a glowing bracket he's been pounding on, pulls it out of the slake still glowing, and resumes pounding?

IIRC there was a bit on the disk (or maybe it was the Pirates of the Carribien disk) where they showed the cleverly painted hunk of wood he'd been "hammering" on. It was quite the sight to see the "glowing hot" piece being passed around bare handed.

Have a look at this: http://en.wikipedia.org/wiki/Vibration_white_finger

And then assess what level of risk is actually faced: http://wwwn.cdc.gov/niosh-sound-vibration/

This thread reminds me of Alex Bealer's Old Ways of Working Wood. An excellent book.

We'll be taking down some maples soon, so I think I need to read it again. (And to bookmark this thread!)

If I were to take a leaf spring of 5160, 'flexible' in the beginning then forge and shape it to a common hunting knife shape then improperly heat treat it, it would end up either too soft and flexible

No, it would not. You would have the wrong elastic limit, but you would not have changed the Young's modulus. It would still take the same force to bend the knife by a given ammount prior to exceeding that elastic limit. It just takes a set more easily, which is NOT the same thing.

Don't take my word for it... TRY IT.

I think (and I could be wrong), this a question of semantics.

Yes. Most knifemakers use the wrong semantics and confusion reigns supreme. I encourage everyone here to learn what these words actually mean.

A looser definition of flexibility includes the ability to return to the prior shape.

A piece of steel returns to shape when we do not exceede the elastic limit. And yes, heat treatment definately changes the elastic limit of a piece of steel.

But heat treatment does NOT change the Young's modulus aka modulus of elasticity. Nor does heat-treating change the modulus of rigidity.

The modulus of rigidity, by the way, is proportional to the third power of thickness. If a knife B is 1.25x as thick as knife A, we need almost twice as much force to bend it the same ammount. That 1.95x force goes into 1.25x the area, though.



And HARDER steel has a HIGHER elastic limit. Again - don't take my word for it, go out to your shop and experiment!!!!

How did a 3 man shop end up with a union?

That's Europe for ya. You've heard of the "E.U." have you not? :D

Vince Gingery put out a book detailing how this can be done by hand with simple tools. Of course if one were trying to make hundreds of such seams, one migh want the Pexto tool.

Seriously, just think how much energy you're wasting swinging a hammer with a dog on your arm!

My 88 pound Scottish Deerhound really doesn't take all that much KE out of my hammering, does she? If only I could train her up as a striker...

By the way... Thank you, Brian! (& others!) The anvil does work better the right way. :)

From what I understand, the proper form for swinging a hammer is as follows:
Elbow near your side, Shoulders back, with most of the swinging movement in the elbow, not the shoulder or wrist. This keeps your hammer, elbow and shoulder in a plane that runs perpendicular from a plane formed by your two shoulders. The muscles being used in this form primarily include your triceps for swinging the hammer to its target, and biceps for lifting the hammer up from where your rebound stops to the top of the arc of your swing.

I'm going to go out on a limb here and respectfully disagree.

I concur the wrist, elbow and shoulder should be roughly co-planer. I concur one should not lift one's shoulder when hammering.

More than just one muscle group should, however, be used for forging.

I'm not saying there was no bad form or no over-exertion. I am saying good form uses the whole body, the right grip on the tool, and the right tool.



I hope your healing goes well enough to impress your physician. I hope you do not have further injury.

A hand-hammer only has so much kinetic energy that I can put into it.

I want as little as possible of that kinetic energy converted to sound or "absorbed" by sand or wood or such. I want as much as possible into that glowing hunk o' metal!

The more the anvil or stand move, the more of my hammer's kinetic energy goes to waste. And that energy comes 100% from MY muscles, doggonnit!

The HC and the mild must both be at welding temp. Welding temp is lower for HC than for mild. Practice on scrap first.

(Easier to just make the whole knife out of the pattern-welded stuff. It's only steel, right? Nothing of any emotional or monetary value, right?)