Steel for toolmaking

[Quenchcrack]

Arfist, it never occured to me to peal you like an onion. You said nothing to warrant it and I agreed with what you said.. Although, I was told by one of our Computer Scientists at work that there are actually 10 kinds of people: those who understand binary and those who don't. :-)

[arftist]

Right Quenchcrack, freshman year engineering consisted of two computer courses, binary and basic. I chose a different path. I did not touch a keyboard for most of my life, reasoning that knowlegde is like a pie and the less slices you try to take, the bigger your one slice will be. The slice I chose was metal. Finaly, with the developments of windows and the internet, the computer became too good of a tool to ignore, so now I am here, trying to add to its usefullness, and continue my education. But I digress, let us now analyse; Mike brought up h-13, a member of the chromium hot work group. These are deep hardening steels, which will essentialy harden all the way through, in small enough sections, IF HELD at critical plus, for soficient time for the heat to travel all the way through, also known as soak time or soaking heat. Whatever tool you are hardening, including knives need sufficient soak time. Thin or heavily machined metal require great care, skill, or knowledge to properly heat treat. This is what Quenchcrack meant when he said anybody can send it out and get it heat treated. The easiest and arguably best way to heat treat metal is in an oven designed for that purpose. However, most needs of the blacksmith can be met with a forge. The only caveat with air hardening alloys is that normalizing ( heating to the upper critical limit, soaking, allowing to cool in air, also known as open air annealing) will cause complete and total hardness. Which brings us to Evfreak. Even h-13 has a limit as to how red-hard it really is. Frequent cooling with water will entend, the work time, work capacity and life span of tools made from the chromium hotwork group. It is also tough enough to be quenched in water, but that is not nessasary. Are you sure it was at it's upper critical temp, or more, and had sufficient time at soak?. Plus it may not be air hard. High carbon tools, while very hardenable, can require frequent dressing and rehardening. That is why air hardening allows were developed. Which brings up to hunt for steel, which is different from gathering steel. When gathering steel, we must be armed with methods, tests if you will, to closely guess their properties. Hunting, is different. We determine the alloy we wish to aquire, by use of a list from a book, which lists all the different alloys of tool steel, and most of the items ever made from said alloy. Then we deduce, from that list, what object, near or available to us, is made from that alloy. Such lists are available in many comprehensive metalworking books, but much more detailed and complete in certain books such as those published by the American Society fo Metals(ASM), but also, ASTM,SAE, you get the idea. The advantage to this technique, is that the information for optimum heat treating becomes a known. Next week, using gathered steel.

[evfreek]

Hi arftist. You asked about spark testing. Spark testing for checking the red hardness of steels absolutely requires standards. These are available over the Internet or from kind fellow blacksmiths. The main alloying ingredients which contribute to hot work capabilities are molybdenum, chromium, or tungsten. See my gallery photos for ways to distinguish the molybdenum spear point. For chromium, most commonly known in automobile spring steel, look for "flowers" along the main shaft. They look like little hairs before the burst end. For tungsten, get some HSS drills, or known M-2. It affects the color and length of the sparks. Drill bits spark with few bursts, and look like low carbon, but they are very hard and hardenable. The color of the sparks is a dull red. Of course, you could always grind TIG electrodes, but these look nothing like steel.

A smith once told me that you could judge hot work potential simply by forging the steel. He said that 5160 and S-7 are similar under the hammer as they are cooling. I am not sure about this, but he has punched a lot more hammer heads with OCS than I have with S-7, so I defer to his experience.

As for cost of tool steels, your observation of high prices from retailers is correct. I have found that Ebay sellers such as Pacific, NES, or Speedy Metals sell tool steel drops for approximately $1 per pound plus shipping. I bought a block of S-7 and D-2 about 3x2x1 for a very reasonable price. You can just cut slices off the end, since they are sold dead soft annealed.

Here is an excerpt of a post I made some time ago:

"The H-13 pieces listed on ebay at rem's (cut offs) from our production cutting o
perations. Here's a sample of sizes (in inches):
2 x 3 x 27, .75 x 3 x 36, .75 x 2.5 x 33, 1.5 x 4.5 x 13, 1 x 2 x 12... Let us k
now if these sizes will work."

[Amoroso 82]

Has any one ever made any tools like an axe from a piece of Railroad track, I need a squaring axe and I have alot of pieces of Railroad track as a matter of fact I have a pile of Railroad metal including spikes tie plates and track, I have discoverd that spikes made after 1970 something are considered by the Railroad to be high carbon and accually say "HC"on the head and they say that these are equal to 1040 steel but I cant find any info on the track, it is probably use hardend but is it suitable for an axe.
Amoroso82

[matt87]

Originally Posted by Thomas Powers

I am citing the Arema (The American Railway Engineering and Maintenance-of-Way Association) 2007 document, Part 2 "manufacture of Rail"

Standard rail steel:
.74 to.86% Carbon,
.75 to 1.25% Manganese,
.10 to .60% Silicon
Minimum Brinell (of unhardened surface) 310 or 370 dependant of grade ordered.

Low Alloy Rail Steel
.72 to .82% Carbon,
.80 to 1.10% Manganese,
.25 to .40& Chromium,
.10 to .50% Silicon
Minimum Brinell (of unhardened surface) 310, 325, or 370 dependant of grade ordered.
My document shows the following breakdown for grades:
SS = standard strength (brinell 310)
HH = Head Hardened (brinell 370)
LA = Low Alloy Standard Strength (brinell 310)
IH = Low Alloy Intermediate (brinell 325)
LH = Low Alloy Head Hardened (brinell 370)

I understand a lot of very good khukuri are made from rail in Nepal. Not sure what the Nepalese surplus rail is like though!

[ThomasPowers]

Sorry as of the 1968 Spec for RR spikes HC indicates a spike of: "Page 5-2-3: Specifications for high carbon steel track spikes 1968. Carbon not greater than 0.30%, nor greater than 0.20% copper."

NOT 1040! 1030 at the *higest possible* level. They don't want brittle spikes!