Time after time I hear that today's stuff is made of Better Metal than were 18th or 19th century guns.
So the parts should last longer.
Such statements grind away at my insides.
I am a metallurgist who has been looking at worn out or broken parts from small power tools, jet engines, mining devices and all manner of high temperature process equipment since 1963.
Yes, some materials are indeed better than others, and any metal can have some accidental defect in it.
BUT when the thing breaks a good exam will show it was almost always the user's "fault" - well, at least he was using the Widget harder/faster than the designer had in mind. I have examined many, many such objects since JFK was happily playing with Marylin. Worked for a specialty alloy supplier 3+ decades and of course the customer always claimed it was our material. Every 5 or 10 years he was quite right, & we made it good (and learned something).
Once in a while there is a material defect - seams in steel, off-chemistry, wrong heat treatment, the absolute worst being we shipped the wrong metal.
But for the most part broken things had not been designed for long use, or weren't machined or assembled in a good manner. Roller's locks are a contemporary examples of products made by a skilled man.
Todays metals are "Better"
? Sure, in automobiles and rocket ships. But "better" can and does mean lower cost of production. Y'all doanwanna hear this when survival of your digits is of concern, but let us stay with lock parts. Original locks were mostly forged & cut from wrought iron, with springs of some steel grade. Most commonly available spring steel was Blister Steel, with the higher quality "Cast Steel" used for clock springs. Blister Steel is of uneven carbon content and contains long slag stringers from the original wrought iron. Not very neat stuff. Now modern springs, except Mr. Roller's & a few others are cast. Investment Cast, a.k.a. Lost Wax castings. Quality? Depends upon the foundry. Chemistry? You hope it was what you asked for. Grain size? Coarse as #@%&!! unless someone was kind enough to anneal or normalize them before hardening. Decarburized - Yes, carbon will burn out of the surface layer in the casting process. Of course it can be restored by a carburizing (case hardening) operation. If someone does this. Tell me, just tell me, that a Modern Cast steel spring is superior to a well made antique of blister steel. Sure.
In my industrial experience it is a good idea to select whatever steel that foundry is accustomed to casting, as that is what you will get. Ask for something different (as did large company for whom I once worked) and you may get a Brand New Alloy, one no one ever heard of before. In the case of my former employer it turned out to be really good stuff, what they should have been using anyway, but it did require different heat treat.
The Frizzen. In 18 - 19th century this would have been forged of wrought iron, with a steel face forged (for military or fine civilian arms) or brazed, for common guns, to it. Today it is wax cast, you hope of 1095 or something similar. Again, grains the size of your eyeballs and carbon burnt out of the surface. Both these things are quite fixable, if one knows to do it.
Better than the old ones? Well, the better lock makers today do know how to deal with this.
Yeah, the best of modern locks
can be superior to old ones but this is by no means guaranteed.
Slag strings in wrought iron we don't have, but many insist on using a steel meant for high production on automatic screw machines. It has sulfur strings, lead partcles, and phoshorous in it to keep from being too ductile (from making those nasty long curly chips during machining). I think this stuff came about around WWII when high production rate was of greatest importance, and the steel mills had to develop the process for actually making bar with such interesting mechanical propertiesa. As I recall 12L14 is great for drill chucks, which have a lot of machining done on them, but don't always get beaten for their entire lives.
Just Ranting & Raving.
Yeah, modern stuff should be, and often is, better but this is not guaranteed.
