Eighteenth century springs

[wmrike]

I don't know where else to put this, so here goes. 

Perhaps fifty years ago in the American Rifleman there was an article that had thin sections of eighteenth and nineteenth century steel/iron used in gun making.  All of it was a mess.  No homogeneity and huge carbon blebs everywhere

Today we have all sorts of steel alloys, each specially made and we can be assured of their content and, by extension, the final product after fabrication and treatment.  We more or less take it for granted.

How did the old timers make springs, given that they started with something whose composition could only be guessed at in a best case scenario, and that only vaguely answered the definition of steel?

[Dphariss]

Steel was generally better than the average iron.
Iron was pretty horrible into at least the 1860s.
Compare the metal in a 1874 Sharps receiver to that in a Borchardt (1878).
1874 is horrid stuff that I think is left over Civil War era iron forgings for percussion Sharps.
The Borchardt has pretty good stuff in it. But there is about 10+ years of advances in steel making in between.
Where the iron came from makes a difference as does how it was made. Repeated heating and beating the iron helped remove impurities. But this made it expensive.
English gun barrels were often made from re-melted horse shoe nails with a little steel added. Since it had been made in the way it was it was cleaner than iron right from the furnaces.
"Colonial Frontier Guns" has a lot of sectioned barrels from trade guns in it. It would cure anyone from wanting to shoot 18th century barrels.
The reason damascus barrels (good ones) were superior was that the metal was cleaned by all the forginga and there were fewer inclusions.
Dan

[flintriflesmith]

...
How did the old timers make springs, given that they started with something whose composition could only be guessed at in a best case scenario, and that only vaguely answered the definition of steel?

I do not agree with the basic premise of your question. Both wrought iron and steel were available in the 18th century in just about any "grade" a consumer wanted. Junk iron with lots of silicon inclusions was good enough for wagon tires, anchor chains, cheap trade gun barrels so that is what was used. If you examine a good quality lock or Jaeger barrel under magnification you will find the iron has been processed to the point where the inclusions are hardly visible. They are certainly present and etching with acid (or naturally by years of rust) will reveal the grain of the iron.

Most steel was made by adding controlled amounts of carbon to highly refined wrought iron. Most of the best steel was imported and sold by grades and country of origin--- Swedish steel, etc.

For springs in a gun lock the finest steel wasn't really needed because, compared for example to a watch spring, a lock spring is huge and thick so a few inclusions do not matter. Far better steel was needed for fine swords, straight razors, etc.

Until practical methods for making crucible steel were invented by watch makers in the second quarter of the 18th century (for their balance springs) the best steel was for cutting tools and was often referred to a "shear steel."

If you care to you can read more about this subject on my web site.

http://flintriflesmith.com/Writing&Research/WebArticles/iron_and_steel.htm

Gary

[northmn]

The process of forging also has a way of improving steel characteristics.  Before the industrial revolution of the mid 1800's steel likely did vary in quality to a degree.  I noted in another thread that English gunmakers for a while preferred Spanish steel.

DP

[Levy]

I can attest to early 18th Century springs still holding their temper after being lost at sea for 275 years.  I have cleaned numerous gunlocks that had tension still on the main and frizzen springs.  On one particular lock, you could still snap the frizzen forward and back (maker: Florkin ALiege).  It looked like a 1st model Brown Bess lock and was recovered from a Ca. 1733 wreck (8Mo 101).

James Levy

[Acer Saccharum]

The Spanish were famous for their steel. Many high end guns of the 17th and 18th Cent used Spanish barrels.

[Dphariss]

The Spanish were famous for their steel. Many high end guns of the 17th and 18th Cent used Spanish barrels.

Until they got their act together the English preferred Spanish barrels from what I have read.
Make one wonder if this carried over from the days of the Moors.

Dan

[JCKelly]

The Old Guys were not dumb. Although it was not yet known that the amount carbon affected properties, they did make steel in different "tempers", those different "tempers" being different carbon contents. If you look closely at specification for modern "W1" steel, which is a plain carbon tool steel, you will find that terminology is still in use. W1 is made to a range of different carbon contents, referred to as "tempers". I have an Italian double-dog wheel lock (lock only) with very nice springs. Look close and one may see long slag inclusions, but they don't hurt very much. You may recall that many crossbows had tempered steel bows.
Since they did not have thermocouple temperature controlled furnaces, they did not necessarily heat treat springs the same as a modern heat treater might. To get the hardness (also known as the "temper") of the spring right, one would perform what is today known as a "slack quench", that is, a rather slow quench that did not develop full hardness. Today the guys who oil quench their 1095 or 1070 springs are performing a "slack quench", though I don't suppose they are charmed by that term. With a slack quench one may then be pretty far off in the reheat process, which today is called "tempering" or "drawing", and still get a useable spring. Not ideal, but much better than having your spring too hard. In which case they can just break all by themselves, under tension in that pretty lock setting on the table there.