steel

I have a question about steel, or the different types of steel. I'm a goldsmith who's fairly new to engraving and am curious about the different types of steel. 440 and such, I see alot of numbers reffering to different steel types but am just not educated with this ferous metal. I do know a little about tool steels like HS steel, tungsten vanadium and such but not much about stainless steel. Please help a novice in this subject, thank you..
Jeff

Jeff,
"Steel" is a hard subject to cover in one post. (No pun intended) I am by no means an expert. What aspect do you need to know: What engraves well vs What to make a knife out of?

Here's a knife making overview:http://www.engnath.com/public/manframe.htm

I might ask what do you want to do with steel. Then I would make some recommendations.

Merry Christmas!

Tom

Maybe this will help a little. the higher the number the harder and tougher the steel ( with stainless steel that is) example 305 stainless (300 series) is very soft and easy to machine. 700 series is very hard and tough, wouldn't want to have to engrave it at all. One of the characteristics of stainless is, it work hardens very fast and quite easily. When machining stainless once you start to cut, don't stop, or it will be work hardend right where you stopped your cut. when engraving this is also true but in a much milder condition.
stainless (in most instances likes a heavy cut at a moderate speed, or slightly higher rpm than mild steel) as such when engraving stainless it works better to move right along and try to cut full depth on the first pass, because the second cut will be thru slightly harder steel. Now this is not always true with all stainless, as it is commonly alloyed to change it's characteristics

Not all stainless is created equall, 440 stainless will work harden very fast, 416 stainless is very forgiving in most instances. Both are 400 series stainless but 440 is alloyed to be very hard and very rust resistant, and 416 stainless is alloyed for shock resistance and toughness, without being as rust resistant.

Now it comes to carbon steels, most will cut fine, if they have not been hardend already. Some exeptions being what they call high alloy steels ( d2, d3, and many other exotic steels made to be used under extreme conditions) 4140, 4130, with the last 2 didgets specifying the carbon content (4140 = .40 percent carbon)
will cut quite nicely up to about 38 to 40 rockwell. This is a common steel used in gun manufacturing, it is a tough, shock resistant alloy that cuts well. When machining it prefers a heavy cut at slow speed, much like when you are engraving, as such it doesn't work harden as you are cutting.

8620 is another steel used in gun manufacturing ( considerd medium carbon), that is tough, and shock resistant when properly heated. treated , It will engrave very nicely. 8620 is designed to be carberized (case hardend) for it's strength.
when it is case hardend or carberized it will be nearly impossible to cut or engrave, without going through a full aneall first ( pack in an air free environment heat to approx. 1400- 1500 deg. and cool slowly Aprox 100deg. per hour. untill the temp. is down to about 700 deg. then it will be very soft and easy to cut. note it will still have the high carbon content on the surface, if you have taken care to not let it decarberize when anealing. ( I pack items in large cast iron box with the used charcoal from pack hardening. this prevents air from getting to the parts, and also keeps the carbon around the the parts to prevent decarberization.) after engraving parts that have been annealed need to be rehardend, and if they are of case hardend steel and have been extensivly reshaped or polished they will need to be recarberized to put the hard surface back on them.

Now bear in mind that metalergy is a very indepth study, this just scratches the surface. But hopefully it will shed some light on the subject for some.

Joe

Thanks Joe, I appreciate the information very much, I know it's quite a large subject but this does shed a lot of light. I guess now I'll head over to wikipedia for some info, but thank you.
Jeff

Go here:
http://www.mcmaster.com/

Scroll to the bottom right of the page to Raw Materials and click "Metals"
There you can click on the metal type of your choice and bore yourself slap to death reading about properties of everything except spent uranium.

Have fun.