Subject: Re: Rockwell at home

From: [email-masked] (Barry Workman)
Date: Wed, 10 Aug 1994 06:56:08 GMT

[email-masked] (James Dollar) writes:

>Consistent heat treating. Is it obtainable in the home shop? Do you
>need sophisticated devices and expensive equipment to achieve good results?

Uh, what do you consider expensive?  There is a small oven available
from Griegers and Laguna Clay in the 200-300 range that can do 2000+
F.  It has a 'stat and is supposed to be accurate +/- 10%.  To me this
is very sophisticated equipment -- I melt aluminum with charcoal --
Dave Gingery has a book, available from Lindsay Publications, *SEE
THE FAQ* that takes you through building an electric furnace using
the heating elements from an electric stove.  Parts available all
over the place.

>Are there any good texts out there on this subject?

Again, pull out your Lindsay Catalog.  There are books on many
subjects including knife making, forging, smithing, and heat
treating.  Read the descriptions carefully.  You will get
EXACTLY what is advertised.

>--
>Jame$ Dollar <[email-masked]>

-- 
    - Barry Workman

---

From: [email-masked] (Mr. X)
Date: Mon, 15 Aug 1994 19:19:55 GMT

> need sophisticated devices and expensive equipment to achieve good results?

	Yes.  No.  But it depends on experience.  If you want to develop
	a good feel for heat treating, it will take time and an certain
	number of failures.  Unless you have the $$$$$$ for  cycled
	heat treat furnaces, you will have to wing it and learn as you
	go aling.  But this is half the fun.
> 
> Blade magazine believes one or two Rockwell points can make a major 
> difference in the edge holding ability of a knife.

	well, I did not read this, but as stated I would have to say
	that this is an oversimplification.  Straight carbon tool steels
	like O1 are relatively easy to get the "feel" for,  They work
	easily and are not particularly onerous to heat treat.  Move
	to 440C and you have an entirely different animal.  440 requires
	a longer soak time because it has a greater refractory characteristic
	than steels like O1.  Steels like D2 and S7 are different still.

	As to how sensitive they are to Rc variations, I have found that
	O1 does not begin to show any serious deterioration until you go
	below, say, 56 or 57.  And getting a hardness in the 58-60 range
	is pretty easy with this material.  440C on the other hand is
	quite a bit less cooperative.  I have found that to get anything
	vaguely resembling file hardness out of a 440C blade, it must soak 
	above transition for a good 20-30 minutes, preferably in a
	carbonaceous material to prevent decarb.  Even so, I have yet to
	get what I would call "good" results with the 440 stainless
	steels.

	When it comes to heat treating, I have found that there are few,
	if any, pat and easy answers.  This is why it is an art, IMO.
> 
> Can I achieve good heat treatment on a avocational budget? Can I test
> Rockwell hardness my self?  Can I consistently hit the 58-60 range?

	Yes, yes, and yes.  As I said, it takes time and practice.
	Portable Rockwell scale hardness testers are available, 
	but they usu. run well over $1K, but if this is really an
	important consideration for you, then it may be worth`	shelling 
	out the dough.

	As far as consistency goes, this depends again on epxerience with 
	any given  material.  Some are easier and some more difficult.
> Are there any good texts out there on this subject?

	Lots.  I would check out the offerings from Centaur Forge.  They
	have many good texts avaiable.

-- 
	-Andy V.	[email-masked]		(Mr. X)

	"I have a high art; I hurt with cruelty those that damage me."

						-Archilochus, 650 BC