Been pondering on what would make good blades other than old Sawmill blades. Anybody know what steel lawnmower blades are made of? And do they vary in the steel used?

i know they bend when ya hit a tree root.

That's pretty much all I've been making my knives from, but I am no where close to some of the talent that is present here.

Keith

You can get an idea of what steels are used for different applications here. I would imagine the listings are general information and would not apply in every case. The last two numbers in the steel's designation represent the carbon content. Try to choose steels above XX40 with XX50 even better. Lin
 web page

WOW, Lin thats a great list. So I am seeing that Lawnmower blades should be 1085 steel is that correct? And do you have a link for the proper heat treating method for 1085 steel?

Last time I checked into this I ended up calling a few companies that made blades my local hardware store stocked.  After getting shuffled around and being on hold for far too long I was told 1065.  A quick google search would have been easier     Another brand (can't remember which at this point) had 5150 listed in the tech section on their website.

Bottom line, if you don't know the brand you won't know the steel without some work.

I'd make the knife, heat it to non-magnetic and quench it in oil.  Temper immediately at 350 degrees and try putting an edge on it.  If it's 1065 that should get you around a 58-59 Rc.  Same with 5150 (I think??)  If the edge is brittle (chop on a 2x4 or do a brass rod test to check) draw the temper back a little more at a higher temp and check again.

I mostly agree with Lin about steel choice, but will add that the as-quenched hardness of 1040 is only around a 56 Rc.  1050 is ~58 Rc as quenched.  The 51XX steels with the same carbon content will get harder.

Maybe Ru will chime in here.  That young man has made a few out of lawnmower blades and may be able to give you specifics on certain brands.

That is a nice list. Thank you.

Jeremy How long would you put it in the oven for 350 for??

Man I cut one out today and put far too much work into if the steel is bad! LOL

I went ahead and cut it, ground the edge, drill it...almost (I used Cobalt bits and each bit only got one hole drilled before it was trashed) and put alot of file work into it. I REALLY hope it works! LOL

Photo Bucket is down right now I will post a few pics of where I am so far when it comes back up.

Jeremy I have no idea       I Just collect the lawn mower blades,a friend anneals them,I cut the blade,heat it to cherryred or non-magnetic temps and quench it in oil,heat it again until it almost blues,let cool,secure handle and... Wa la a knife.
  :confused:    :confused:    

Here are the pics. I am gonna go out tomorrow and get some more drill bits to finish drilling the holes and then I will heat treat it and see what happens. I will post a completed pic maybe tomorrow evening.

Dang Son that looks great! when you use cobalt I find if you drill slow it works better.<><

Nice knife Lewis!

Looking good, hope it turns out to be right for you.

Lewis, Looks pretty good to me. Hope it works out for ya too and here I've been throwing out my mower blades for years.  LOL

Lewis Heat that baby up and see what ya get? That is one very nice looking blade. I taught you well grasshopper!            <><

It was that hard to drill into??!  That's surprising.  I thought the mower blades were normally tempered in the low 50's.  Frank is right, I've found slower speeds generally are a better idea for drilling - burn up fewer bits.  Those things ain't cheap!

I normally draw the temper back in the oven for 45 mins or so... or about the time it takes me to rough out a few more blades.

I highly recommend using a magnet to check for the critical temp.  Color of the steel can be deceptive depending on the lighting.  After you quench that blade try to see if a file will cut into it at all before tossing it in the oven.  Oh, and if you're using the house oven be sure to clean off all the oil before putting it in!    

Ru, knife making made easy  :D   Are you bringing any to Shawn's?

Well I made another today, I will post pics in a sec. But the new cobalt bits I got wont even drill into this one at all!

I always use a magnet cause I am not experienced enough to judge by color. I am going to get these things cooked tonight and hopefully put scales on tomorrow. I going to put Osage on both of them, gotta love the Yalla wood! LOL

Here are the pics. Unfortunatley on the new kife the mower blades serial numbers were too deep to grind off. The first blade actually had the word Snapper across the blade but it was etched in pretty shallow and i was able to grind it out. Oh well I guess it gives the knife a little "Character"! LOL

Dude those SAWEEEET! Those knives will have soul. <><