Hand Tool Metallurgy

[Dan Sheehan]

I'm trying to get to the next level of understanding. think I get the big picture on many hand tools. I've used both vintage and modern planes, saws, chisels, etc..... Now I wanet a few gory details.

Are there sources that will help me understand hand tool metallurgy?

For example: what is "Spring Steel", what does "Swedish" and "Sheffield" mean in terms of physical properties? What does the number "1095" mean for saw plate steel? What did Stanley use for plane bodies and irons and what about Record, Millers Falls etc.? What is Ductile Iron and Bronze and why does it matter? What do the names A2 and O1 steel mean? What does the Rockwell hardness scale mean for the layman? Pros and cons for each? Etc...etc...

These are the things that keep me awake at night.

I am not soliciting answers to all these specific questions, and more, here and now. I'm just looking for a reference source, either online or in print. Of course any information in any form would be most welcome.

Thanks in advance for your help. Dan

[Shaun Mahood]

Dan, Ron Hock's book "The Perfect Edge" has a section on metallurgy, and is my favourite book on sharpening in general.

[george wilson]

Spring steel is any steel that can be tempered to make a spring. That includes oil hardening 01(which is the basic oil hardening steel). For purposes of woodworking tools we mean the water hardening spring steels usually 1095,1080,and 1070. 1095 means as follows: the 1 means it contains iron. The 0 means no other alloys. the 95 means it contains .95% carbon. 1095 is the highest grade of spring steel that is used these days in the best saws,made by makers like Wenzloff,LN,LV, and other relatively small,exclusive makers,me included,though I'm not presently offering saws for sale.1080 means .80% carbon(8 10ths. of 1%),etc. I made saws from 1095 and also made other tools for Colonial Williamsburg when I was toolmaker there. Spring grade steels can be gotten VERY hard,though,up to 67 RC. But such hardness lacks mechanical strength,and the steel would be brittle like glass. Drawing steels down sacrifices some hardness for toughness. It's a balancing act. A good file is about 65 RC. Because of the tiny teeth,they get by with being so hard and brittle.

Stanley used cast iron for their plane bodies except for a block plane model that was made of thick,folded steel sheet. The cast iron planes can break if dropped. Today,the better makers use malleable or"ductile" iron,which is cast iron that has been kept at a red hot temperature in a furnace for hours so that some of the graphite is burned out of it. LN,LV fall into this category.

In the 18th.C.,Swedish steel was imported by the English because it was better than English steel. They didn't know why back then,but English steel had sulfur in it. Bad steel sank the Titanic. Swedish steel was smelted with wood,and didn't get sulfur in it. Sheffield steel today is perfectly good steel,with controlled amounts of materials in it just like USA or German steel,or steel from any other industrialized country. Chinese steel is suspect because quality control is not very consistent,and things like ball bearings have been found in Chinese steel by machine shops,when they wrecked a cutter trying to machine it. Their cast iron is not real good either. Japanese plane irons and chisels are excellent,and fall in a category all their own as to the chemistry of their steel.

Record,Millers Falls,and every other old plane maker (in the early 20th.C.)used the same materials. There were some English and Scottish companies that made premium planes from dovetailed low carbon steel or wrought iron. They cost more. Those old makers like Spiers and Norris are defunct. Some makers started making dovetailed body planes even in the 18th.C.. Examples of planes made from wrought iron date back to the 1500's.

Wrought iron planes don't break when dropped(but they might bend!)

The Romans made metal planes stuffed with wood.

A2 is the basic example of air hardening steel. It has alloys,like chrome, that enable it to harden just in still air. It is more stable than water or oil hardening steels,distorting very little because it isn't shocked by being immersed in water or oil to cool it fast enough to harden. I use A2 a lot. It will stay sharp longer than 01,but I have found it won't get quite as sharp as 01. 01 will stay sharper than 1095 longer,BUT,the simple,water hardening steels like 1095 will take a sharper edge than more advanced steels,generally speaking. It just doesn't last as long. The water hardening steels like 1080 and 1070 are inferior to 1095 because they contain less carbon. But,on many of the best brands of old saws,these metals were used. Those old saws are much softer feeling when you file them to sharpen their teeth,than the best 1095 saws that are offered today .

The most used Rockwell scale used today for steel is the Rockwell C scale. A good 1095 spring steel saw blade is about 52 R.C.. File hard,as mentioned, is about 65 RC. Some plane makers advertise that their irons made of 01 or A2 are 60RC,but this according to the books I have read,and according to my own experience,are too hard to retain the best cutting because the microscopic edge breaks off,and the tool seems dull. I have found that the OLD plane irons that I used which could BARELY be filed a LITTLE,with a new,fine toothed file,retained better edges. That would put them at about 55 RC.

It's late,and I'm tired. Any mistakes,correct me.

[Mike Henderson]

George gives good advice. Let me just add that if you want some history of the development of steel, see the books "Steelmaking Before Bessemer" by K.C. Barraclough. It's two volumes, Volume 1 - Blister Steel and Volume 2 - Crucible Steel. You'll understand what the term "Cast Steel" on some old plane irons mean.

And if you want to know more about the collapse of the American Steel Industry in the 1980's, read "And the Wolf Finally Came" by John P. Hoerr.

Mike

[Brian Kent]

I love this place.

[Allan Froehlich]

Dan, Ron Hock's book "The Perfect Edge" has a section on metallurgy, and is my favourite book on sharpening in general.

I agree!

The primary reason I purchased this book is because Ron goes into detail about different steels and heat treating.

[raul segura]

It's late,and I'm tired. Any mistakes,correct me.

Great write up and references for use in tools and comparisons.
Thanks for staying up.

[John Oliver35]

I knew when I saw the topic Metallurgy and that George had replied that this would be a great thread! Thanks for question Dan, and George et. al for the replies.

[Joe Bailey]

Thank you George - a nice little synopsis there.

[Larry Frank]

Just a short comment about A2. While it sounds simple - air cooling, this grade is quite complex to get the most out of it and maintain dimensional stability. The chrome and moly in the grade result in it not completely transforming with an air quench. The heat treatment requires quite a few controlled steps and even cryogenic treatment. (The cryogenic treatment is used to transform retained austenite which prevents later dimensional problem.)

One could just do a simple heat treatment with this grade. However, such treatment will not take full advantage of the grade.

In my opinion, it is much easier to successfully heat treat steels such as the O-1.

[Dan Sheehan]

[QUOTE=george wilson;1905101]Spring steel is any steel that can be tempered to make a spring. That includes oil hardening 01(which is the basic oil hardening steel). For purposes of woodworking tools we mean the water hardening spring steels usually 1095,1080,and 1070. 1095 means as follows: the 1 means it contains iron. The 0 means no other alloys. the 95 means it contains .95% carbon. 1095 is the highest grade of spring steel that is used these days in the best saws,made by makers like Wenzloff,LN,LV, and other relatively small,exclusive makers,me included,though I'm not presently offering saws for sale.1080 means .80% carbon(8 10ths. of 1%),etc. I made saws from 1095 and also made other tools for Colonial Williamsburg when I was toolmaker there. Spring grade steels can be gotten VERY hard,though,up to 67 RC. But such hardness lacks mechanical strength,and the steel would be brittle like glass. Drawing steels down sacrifices some hardness for toughness. It's a balancing act. A good file is about 65 RC. Because of the tiny teeth,they get by with being so hard and brittle.

Stanley used cast iron for their plane bodies except for a block plane model that was made of thick,folded steel sheet. The cast iron planes can break if dropped. Today,the better makers use malleable or"ductile" iron,which is cast iron that has been kept at a red hot temperature in a furnace for hours so that some of the graphite is burned out of it. LN,LV fall into this category.

In the 18th.C.,Swedish steel was imported by the English because it was better than English steel. They didn't know why back then,but English steel had sulfur in it. Bad steel sank the Titanic. Swedish steel was smelted with wood,and didn't get sulfur in it. Sheffield steel today is perfectly good steel,with controlled amounts of materials in it just like USA or German steel,or steel from any other industrialized country. Chinese steel is suspect because quality control is not very consistent,and things like ball bearings have been found in Chinese steel by machine shops,when they wrecked a cutter trying to machine it. Their cast iron is not real good either. Japanese plane irons and chisels are excellent,and fall in a category all their own as to the chemistry of their steel.

Record,Millers Falls,and every other old plane maker (in the early 20th.C.)used the same materials. There were some English and Scottish companies that made premium planes from dovetailed low carbon steel or wrought iron. They cost more. Those old makers like Spiers and Norris are defunct. Some makers started making dovetailed body planes even in the 18th.C.. Examples of planes made from wrought iron date back to the 1500's.

Wrought iron planes don't break when dropped(but they might bend!)

The Romans made metal planes stuffed with wood.

A2 is the basic example of air hardening steel. It has alloys,like chrome, that enable it to harden just in still air. It is more stable than water or oil hardening steels,distorting very little because it isn't shocked by being immersed in water or oil to cool it fast enough to harden. I use A2 a lot. It will stay sharp longer than 01,but I have found it won't get quite as sharp as 01. 01 will stay sharper than 1095 longer,BUT,the simple,water hardening steels like 1095 will take a sharper edge than more advanced steels,generally speaking. It just doesn't last as long. The water hardening steels like 1080 and 1070 are inferior to 1095 because they contain less carbon. But,on many of the best brands of old saws,these metals were used. Those old saws are much softer feeling when you file them to sharpen their teeth,than the best 1095 saws that are offered today .

The most used Rockwell scale used today for steel is the Rockwell C scale. A good 1095 spring steel saw blade is about 52 R.C.. File hard,as mentioned, is about 65 RC. Some plane makers advertise that their irons made of 01 or A2 are 60RC,but this according to the books I have read,and according to my own experience,are too hard to retain the best cutting because the microscopic edge breaks off,and the tool seems dull. I have found that the OLD plane irons that I used which could BARELY be filed a LITTLE,with a new,fine toothed file,retained better edges. That would put them at about 55 RC.

It's late,and I'm tired. Any mistakes,correct me.[/QUOTE

George: I have followed your contributions for a couple of years now. Here you have out-done yourself. You have provided much more than I asked, and I am very grateful for your generosity. You are a wealth of knowledge. Have you thought of publishing something on this important subject? I hope you would consider that project. But I've asked too much already... Thank your for your gracious assistance. Dan

[george wilson]

There are already books available that give this type of information. One of my favorites is "Sheffield Steel" byK. Barraclough,published by the Moorland Publishing Co. in Buxton,Derbys,England. 1976. I must have bought my copy in England,because the price is in pounds,4.20.

Probably not available these days,but if you keep on Ebay one might turn up. I also have read "Reamour's Memoirs" with great interest. This was published in the 18th. C.(possibly 17th.C.) I got it in paperback,but I believe it is in the Colonial Williamsburg library. He was a 17th.C. nobleman in France,who the king sent to England to spy and learn how they made high carbon steel. The French did not know how to make tool steel,but apparently mined it naturally from some limited source they had. In Germany,they mined a natural tungsten steel called Wolfram. In Scotland(IIRC),a natural stainless steel was mined. We have an 18th.C. fireplace set in Williamsburg made from stainless steel. Some of the all metal Scottish flintlock pistols were made from stainless,and were highly prized since they didn't rust(and made a good club in battle).

Not much at all was known about chemistry until about 1830. I have a civil war era chemistry book which is about 1 1/4" thick. It is full of statements like "It IS THOUGHT". I have a1903 chemistry book by the same publisher that is over 3" thick. It is remarkable what was known,and provable by then.

There are several modern text books on tool steels as well. I like the book on Sheffield steel because it deals intimately with the history of steel making processes.

[Mike Henderson]

In addition to the books already noted in this thread, let me list a few others:

American Iron 1607-1900 by Robert B. Gordon
A Nation of Steel - The Making of Modern America, 1865-1925 by Thomas J. Misa
Technological Change and the British Iron Industry 1700-1870 by Charles K. Hyde
History of the British Iron and Steel Industry from c.450 to AD 1775 by H.R. Schubert
Iron and Steel in the Industrial Revolution by T. S. Ashton
Alexander Holley and the Makers of Steel by Jeanne McHugh
Wrought Iron - Its Manufacture, Characteristics and Applications by James Aston and Edward B. Story
The Epic of Steel by Douglas Alan Fisher (not so good)
Out of the Fiery Furnace - The Impact of Metals on the History of Mankind by Robert Raymond

And a couple of others:
Stronger than a Hundred Men - A History of the Vertical Water Wheel by Terry S. Reynolds (very interesting book)
A History of Metallography - The Development of Ideas on the Structure of Metals before 1890 by Cyril Stanley Smith

But the best books on the history of iron and steel are the "Steelmaking before Bessemer" two volume set by K.C. Barraclough. Expensive to buy but may be available through inter-library loan at your local public library.

Mike

[george wilson]

I'm too tired this late to list more books!!:) I stay up late,and do not get deep sleep. The meds are worse than the continual tiredness,though.

[Ron Bontz]

Great thread. Thank you, George. If I start now I just might read those books by the time I am ninety. Maybe I should start with Ron Hock's book.