My regular seasonal job is working at a tree service as a faller. As you can imagine we go through a lot of chipper knives. Now once they are worn past a certain point they cannot be put back on the chipper. The boss will give me all of the old ones I want, But what would I do with them? I have a few ideas but mostly I a kinda at a loss for ideas for some reason. They seem to be EXTREMLY high carbon steel and are tempered REALLY hard.

Are they HSS?  If so they are not a blacksmith friendly material.  Ask whoever orders the replacements what they are.

If you have a forge, an anvil and a hammer, try and make a knife like object out of one of them.  Work the steel only when it is nice and hot, don't keep working it as the color goes out of it.  If you can forge it in to a knife like shape, quench it in oil to see if it will harden and if it does, temper in your oven.  Then you have a knife like tool. 

HSS is high speed steel, and takes a special heat treatment as well as forging techniques. When it is hit with a grinder it gives off faint  sparks, not big sparklers.

I have resharpened chipper blades on my surface grinder. The ones brought to me were more of a medium carbon steel, as they had dents, and ground easy enough. The blades were left tough instead of brittle hard to withstand the abuse from nails, etc..

See if you can find out the manufacturer, and contact them. I have done that with several items and usually find the companies very helpful.

They might make decent guillotine tools if they're thick enough. Probably some kind of high vanadium abrasion resistant stuff that is difficult to heat treat and doesn't hold a fine edge, idk ask the manufacturer.

So as to size they are 5in wide and 12 in long with 4 holes in the middle that are 3/4 in. Most are 1/2 in thick but the new ones coming are 5/8 thick. As near as any one can tell me they are 1095.

Try some junk art! They weld easily and make great bird wings, giant insect wings, whatever!

1095 is a classic steel for knives; but I would double check as I don't recall it being a good steel for chipper blades.  Contacting the manufacturer would be my suggestion too. (And please let me know if I am wrong---you don't have to hit me with a tree to teach me something new!)

it wouldn't surprise me at all if they are 1095 or something close to that!  Most of my lawn mower blades are about 1090.  Most European mfrs of scythes use something very close to 1090 also.  My experience suggests that higher carbon steels seem to have an inherent toughness that persists even when they are not hardened much or are tempered to lower hardnesses.  High carbon steels tempered to lower hardnesses are still much more durable for cutting blades that have to take a beating... and the steel is still quite reasonably priced, compared to slightly fancier alloys.  This works out well for us blacksmiths!  These same steels repurposed, hardened and tempered to a bit harder finish can make good knives, chisels, drawknives, gouges, etcetera!

Those are some hefty blades. Lots of uses , especially if you can pin down the alloy they use.

Higher carbon steels are generally more brittle not tough---look at the charpy tests---"Increasing %C decreases fracture toughness although increasing strength" ; what they are is more wear resistant which is why they get used for things like plows and disks and ground contact tools.  I would expect that some of the High Alloy steels would make better chipper blades as they tend toward lots of carbides; but then cost factors in---just like jack hammer bits.  (OTOH the cost of replacement time also factors in...)

Good Morning Mad Max,

They will make awesome 'Hot Cuts'.  Cut a 4-5" piece, weld it to a piece of square that will fit your Hardy Hole, finished.

It will then fit your vice as well.  Sometimes chipper blades are like a D2. Yes I have some, I don't need any more.

Neil

Acually I just found out that they are not 1095. They are a special alloy called HS411. It is only made specifically for chipper knives and similar things. Our shop foreman says it is nearly impossible to weld it. It is so hard that it chips like glass when its broken. I think ill pass on it for now.

I must be doin somethin wrong because I can't find anythin on the web about hs411. I was curious about it so I tried a few different searches and I get results like steel conduit clamps and other electrical stuff.

I did find reference to a8 as chipper blades.

On ‎1‎/‎21‎/‎2016 at 1:44 PM, Michael Cochran said:

I must be doin somethin wrong because I can't find anythin on the web about hs411. I was curious about it so I tried a few different searches and I get results like steel conduit clamps and other electrical stuff.

I did find reference to a8 as chipper blades.

I doubt you are doing anything wrong. I actually talked to the guy who we get them from and he said that hs411 is made strictly for the manufacture of Chipper and planer blades and is not sold to anyone who does not make them. So I guess you cant buy it in a raw form. I messed with a piece of one and I want nothing to do with it. I had to get it to near white heat and it still hardly moves under the hammer. I tried an arc weld on it and our shop foreman was right, its near impossible to get a weld to stick to it. So I don't really care what it is now as its not Blacksmith friendly at all.

I thought briefly it could be fun to play with. However after reading a little about a8 I realize it wouldn't be worth anything to me lol. It's a shame you can't use it, a supply of good free steel has been a dream of mine since I started this wild ride.