Hank Rearden

I want to begin with telling you this chapter was loaded with great technical information. I recommend finding a copy for your personal library just for this chapter. I'm going to give a quick over view of what you can expect to find.Then I'll share some of the technical data. Because this topic has so much information it will take a few times for me to edit this post to put all the info here. So until I remove more to come at the bottom of this post I'll be adding to it in a few days.

I want to inform you there's a link on the home page to a website for easy reference that match similar steels from other manufactures the steel manufactured by Carpenter Steel Co. and used to write about the spark test. This paragraph also links to that page.

After a quick introduction they write about the proper way to use a grinder. From R.P.M to the diameter of the grinder and the grain size of the abrasive material. Here are a few bullets form this section.

The effect of wheel speed
The effect of wheel grain size
Dressing the wheel
Preparing the sample
Hardened vs. annealed tool steels
How hard to press
Where to make the test
How long does it take to learn?
Picture of the sparks.

Then it goes into the characteristics of how each element sparks

For example: "Carbon. Causes bursts---the higher the carbon the more plentiful and complicated the bursts, (see No. 11 Special) except in steels containing appreciable amounts of alloys, (see speed Star and T-K).

You'll find description on the following elements.

Manganese
Silicon
Chromium
Nickel
Tungsten
Vanadium
Molybdenum

Another example: Chromium. Suppresses the stream and the burst---imparts an orange color.

Disclaimer; not used to analyze the steel.

Following this is a description of each steel they manufacture by name and the details of how it sparks. They separate oil harden and air hardened steel as well. Those details are separated into color, carrier lines, length of lines, ends of lines and star bursts. There are also diagrams on how the sparks are thrown off of the grinding wheel including the size and volume and how the sparks wrap around the grinding wheel.

The final Instruction tells you not to look at the sparks as a whole. Instead to pick out the details one by one. The most important feature is the end of the carrier line. Once you are trained to see how the ends vanish then the other details will be easier to distinguish. They even give a comparison of two different steels that made me feel like they we're describing fireworks exploding.

The final paragraph lets you know what a spark test can and can not do. But if you have a few known steels around then you need to test an unknown you're more  able to quickly draw a conclusion to what you might have.

This book is on eBay for a few bucks.

I'll try to post a picture of the diagrams soon. Now that I have this up, I'll try to post more details on the bold bullets above later.

To book review

   

code[Maglio.gif]  Keep the fires burning hot!
2020 ABANA Conference in Sarasota New York. June 3rd. through June 6th. Plan now!
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jmccustomknives
I've always found the spark test to be somewhat subjective.  It will point you in a direction but further testing needs to be done.  A strong wrought iron spark is about the only one I'll call for sure, even then I've got some round stock (circa 1900) that has a steel like spark but has a grain and will split like wrought. 

Rule #10;  "I can make that" translates to; "I'm to cheap to buy it new."

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Metalmelt
I hadn't looked at the thread because I don't think a spark test can tell you much. That's because of all the variables you mentioned in the first post. It may give you an idea of carbon range but not much else. I analysed steel for several years in a steel mill, we could tell if there was carbon in there or not much by the grind on the sample. Temperature of the sample makes a difference too. High Manganese will lower the spark amount. High being 1.00% or higher. It's all a crap shoot, but gives you an idea of what your dealing with. You can sure tell the difference between 1018 and 1045. I'm old so I have to mark my metal several places so I don't have to remember what I have. Several places because I always seem to cut off the markings.
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Hank Rearden
This book was written for mills and machine shops or professional settings. I felt the information was worth posting to show depth on the subject.  I have illustrations in a pdf format. I'm trying to convert them to jpeg to post for all to see. These are specific to tool steels. Marking your steels was mentioned as good practice. It's going to take another trip to staples to get it right.
code[Maglio.gif]  Keep the fires burning hot!
2020 ABANA Conference in Sarasota New York. June 3rd. through June 6th. Plan now!
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Metalmelt
I didn't mean to sound like I was against the book or practice. I guess I was trying to say I'm not very good at it.
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