I’m new to forging and living on a farm, I have a nearly endless supply of random metal. Of that metal, I have 20 or more cylinder bars and I was wondering what I could do with them. I’m trying to make knives using rasps and I’ve been told that cylinder bars are good steel so I was hoping to be able to make knives from them, but what is doable with them and what kind of metal are they? Thank you

Britt, welcome aboard from 7500' in SE Wyoming.  Glad to have you.

If you put your general location in your profile we will be able to give you better answers.  A surprising number of things are geography dependent.  This is a world wide forum and we don't know if you are in Lapland, Tasmania, or Tierra del Fuego. "Cylinder bars" may be known by a different name other places in the world.

I am not a farmer and have absolutely no idea what "cylinder bars" are.  Could you please describe their use and appearance?  There are a few ways to test an unknown steel to determine what it may be most suited to.  The easiest is a spark test where you touch an abrasive wheel, ususally a grinder of some sort, and look at the sparks it creates.  The length, color, and number of secondary bursts (like little fireworks) will tell you a lot about the metal.  Generally, the more bursts, the higher the amount of carbon in the steel.  Other alloyed metals can affect the sparks but that is the quick and dirty explanation.  Google spark testing of steel and you will get lots more information.  I am sure there are plenty of You Tube videos.

"By hammer and hand all arts do stand."

Welcome from the Ozark mountains. Like George said cylinder bars must be a local term. I have also have never heard of them. Maybe a picture of one will narrow down what it is.

Cylinder bars area parts of the thresher of a combine. They’re about 5 foot long, curved and about 3/8 of an inch on the middle tapering to an 1/8 inch. It’s the piece second from the right. 

Cross-post with the OP.

What I found when googling "Farm Cylinder Bars" was some form of combine part.  To me they look like flat stock with numerous holes and chopped up edges.  I suspect they are some form of steel that is tough, but doesn't necessarily get very hard (like lawnmower blades), but that is just a guess.  May not be what the OP had in mind, but is suspect it is.  Personally I lean towards using known steel for making blades these days as the steel cost is only a small fraction of the investment (unless you are using something exotic), certainly in comparison to your time and proper abrasives. 

Here is a photo and drawing:

   

The ones I have experience with, from my combining days, were tough to resist wear. We would average 4 years custom combining, 6 months per year, per machine and not wear them out. I do not think they would be good knife steel, but would make good tool steel.

15 hours ago, BrittS said:

good steel

Remember that "good steel" is entirely relative. Good for what? Good for knives? Good for anvil tools? Good for axes? Good for springs? Good for balcony railings? Good for tongs?

Les L on the right track with:

41 minutes ago, Les L said:

I do not think they would be good knife steel, but would make good tool steel.

But remember that different manufacturers may use different alloys which both have different secondary uses and present different hardening challenges. I just did a quick Googling of "combine cylinder bar alloy" and found out that some are made from a chrome alloy for rust resistance (might be good for chisels and punches, but depends on other alloying elements), some are made from high-boron alloys for toughness (presents real difficulties for proper heat treatment in a forge setting), and some are chrome plated (DO NOT FORGE -- CANCER RISK).

Hope this helps.

They’re John Deere and most are rusty on the surface. 

That’s a good sign. In rust we trust. 

As has been mentioned "good"  has nothing to do with carbon content.  Deep draw steels with almost zero carbon in them are GREAT STEELS for deep drawing and almost worthless for knives...

3 hours ago, ThomasPowers said:

Deep draw steels

Thomas, please forgive my ignorance, but I have never heard the term “deep draw steels” can you explain what type of steel this is, how to identify it and what it’s good to use for?

Les, I'll respond first but Thomas may have more to add later.  Deep draw steels are ones that are very malleable and can be formed cold in dies to make complex shapes without tearing.  The steel used to make an Altoids mints box would be a fine example of a use of a deep draw steel.  I am not sure of the metallurgy but I know they are very low carbon.

GNM

George, thanks for the information, I have an additional bit of knowledge thanks to the knowledgeable members of IFI

If you have 20 of them all the same brand, it is worth doing some testing to find out. 

Professional knife makers use known steels for the convivence and ease, however 

for practice you can certainly reuse used tool steel if they meet enough criteria. 

I don't have all night to explain it to you but if you search this site you should be able to find guidelines to use junk yard steels.

Rasps can make good knives but certainly grind off all the teeth before you start. 

Old circular saws are usually a very good alloy for practice knife making as well.

McRaven does a pretty good job of explaining junk yard steel knife making as well as

Weygers.