Jump to content
Sign in to follow this  
Keith

bush hog blades

Recommended Posts

I have a large blade that come off of a bush hog.Is there any way to tell what type of steel it is,or would anyone have an idea.It is pretty tough to grind,just wondering if it might be good for forging.

 

Thanks,Keith

Share this post


Link to post
Share on other sites

Well most files are 1095 steel, so take a file to the blade and see how easy it is to file. If it seems like your file is just skating off/ the teeth are getting ruined then the blade probably is close to having the same carbon content of 1095. Running a file against a flat area on another file will give you a good idea of what skating means , but don't do this for long because it will ruin the teeth of the file, they will start to become shiny from being worn away.

 

You could also try doing scratch tests, try to scratch the metal using a pointed part of a file, hardened steel will not scratch easily and there might be a very fine but hardly notice able line, while you can actually feel the softness of non hardened steel and there will be a very noticeable line.

Edited by nabiul

Share this post


Link to post
Share on other sites

Nabiul, I'm afraid you're gonna start developing a complex about me :ph34r: , and I'm certainly not trying to pick on you, but:

 

The file test doesn't prove anything about carbon content except to show if there's enough to harden, and even then it only works if the stuff is not tempered after hardening. I don't know what bush hog blades are made from. Fully hardened 4140 will skate a 1095 file with 40 points of carbon, and 1095 tempered below Rc55 or so will not. Properly tempered mower blades should not skate a file. If they do, they're too hard for the intended use and would chip or even shatter. Liability lawyers tend not to allow that with mower blades.

 

Keith, whatever it is should be forgeable, and hardenable in oil given the intended use. You can either ask the manufacturer, or experiment with hardening using junkyard steel rules. It's probably a low alloy steel like 5160 or 6150, but there's really no telling.

Share this post


Link to post
Share on other sites

There are different levels of what people call skating. I compared how much files skate on other files at different levels of hardening, a freezing water quench, worst thing next to brine will completely ruin a file, a warmed water quench will ruin a file also but the file will bite in a tiny bit for a couple of strokes, an oil quench will ruin the file a little slower. I also 'hardened' A36 or what they call weld steel in freezing water, even at maximum hardness a file will easily bite into it. I've also tried tempering the pieces somewhat and it didn't seem to make a difference. The file test is only to get an idea of how reliable the steel is. Imo, a scratch test using a pointed file is better because you can tell how much pressure is needed to get a good scratch. Yes the file test isn't much good, which is why I keep my broken knives each with a different level of hardening as a reference, fully hardened or not, 40 points of carbon won't stand up to being scratched from fully hardened 1095.

 

Indeed the file test only gives an idea of how hard the metal is after hardening, which is what matters in scrap forged projects. I personally won't be recycling steel anymore for blades though.

Edited by nabiul

Share this post


Link to post
Share on other sites
fully hardened or not, 40 points of carbon won't stand up to being scratched from fully hardened 1095.

 

Straight carbon steel perhaps, but 4140 is not straight carbon. Chromium carbides do fun things to hardness. I make my engraving tools from 1095, trust me, I know what they are capable of scratching with a sharp point. ;)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×
×
  • Create New...