How were forming dies for locks made?

[44-henry]

Yes, crucible steel is well-known, and there is evidence suggesting that the process for making it may have been discovered centuries earlier than generally accepted. For those interested, the Ulfberht Viking sword is worth researching. However, early crucible steel was primarily produced as cast ingots, which were then forged into bars or other shapes. The ability to cast steel into useful, semi-finished forms didn’t emerge until the late 1800s, and even then, it was limited to large, rough applications. From my understanding, investment casting of steel was only developed in the mid-20th century.

Don't forget Crucible Steel, "There is unimpeachable evidence that Benjamin Huntsman was casting steel by the end of the 1740s and that the technique was taken up by others—although not by many—in the three decades that followed. And there can be no doubt that Sheffield stood out as the world centre of crucible steel production in the early 19th century."
https://hmsjournal.org/index.php/home/issue/view/22

This kind of thing was normal dinner time conversation at our house when I was in Elementary School in Birmingham, AL and Dad was a metallurgist @ USS


Best regards,
Carl

[whetrock]

These terms can be confusing. The old wording was different (as Clark commented). Maybe this is already clear from what 44-Henry posted above, but just to make it really clear, 18th-19th c. "cast steel" (as a compound word), is not the same as 20th c. and later "cast steel" (verb plus noun, where melted steel is poured as liquid into a mold).
The 18th-19th c. version is just another name for crucible steel. The alloy components were melted in a crucible to make steel. The ingots were then forged or rolled (to make sheet steel for saws, plane blades, clock springs).
So when you buy an antique Sheffield backsaw stamped "cast steel", it doesn't mean that metal was melted and pouring into a mold in the shape of a saw. It just tells you what type of steel was used. As Clint said, 18th-19th c. cast steel was just a raw material. As I understand it, the big advantage was in consistency (even mix) throughout the product.


Here's a brief description I found yesterday (from https://www.thoughtco.com/steel-history-2340172 ):

One of the earliest forms of steel, blister steel, began production in Germany and England in the 17th century and was produced by increasing the carbon content in molten pig iron using a process known as cementation. In this process, bars of wrought iron were layered with powdered charcoal in stone boxes and heated.

After about a week, the iron would absorb the carbon in the charcoal. Repeated heating would distribute carbon more evenly and the result, after cooling, was blister steel. The higher carbon content made blister steel much more workable than pig iron, allowing it to be pressed or rolled.

Blister steel production advanced in the 1740s when English clockmaker Benjamin Huntsman while trying to develop high-quality steel for his clock springs, found that the metal could be melted in clay crucibles and refined with a special flux to remove slag that the cementation process left behind. The result was a crucible, or cast, steel. But due to the cost of production, both blister and cast steel were only ever used in specialty applications.

[rich pierce]

The remaining question is, what forms of iron/steel did colonial and Federal period blacksmiths use to form dies?  Not what existed in that time frame (good to know but may not answer the real question).  We know steel was expensive.

[whetrock]

Thanks for bring us back to the original topic, Rich.

I just skimmed Gary Brumfield's JHAT article that was part of the original discussion. I may have missed something, but the only thing I see about it is what he wrote on page 27 (which is the same thing he quoted above in his 2009 post):

Dies of this general type are used for a number of lock parts, and they are all made in the same fashion. A steel master is made in the shape of the desired finished forging, and the metal for the die, either iron or steel forged to fit the anvil, is brought to a bright orange and the cold master is hammered into it. Several heats may be needed. Forge scale is cleaned out, and the corners sharpened with files and chisels.

Gary also discussed details about case hardening, on page 78-79 of the same volume. Were iron masters also case hardened to make them tougher? Would be nice to know.

[Habu]

The only colonial period dies I've examined were from a wagon shop.  They were made of a better-than-average grade of wrought iron.