blade mistake

[awm]

as ive posted ive been coldfiring my blades. had one that needed straitening but figured id do it when i got it back. bad idea.
so far a 3 lbsledge,front of my truck and vise still cant bud it.
dont know what the moral of this story is but i hate to heat it
as that reverses the process.

[jaybee]

Any bent blade should be thrown away.

[Fantasy Lawns]

ya I'd have to say ....it's done

[sparechange]

awm, i don't think i would want to use a blade i had tried to straighten, but as i understand the cold treating process, it is permanent unless you take the steel back to a molten state. i could be wrong on this, but i believe i read that somewhere.

[Eric ELM]

I would of gotten new blades for the coldfire. I wouldn't straighten them. Remember the BIG thread on that last winter?

[65hoss]

I'd say its "well done". (pun intended)

I noticed at NAPA yesterday they have blades for most all mowers. I saw all the commercial mower blades listed in the parts book. Just thought people might like to know this.

[leeslawncare]

sorry guys i'am lost . what do you mean by coldfiring?

[geogunn]

awm--seriously, what do you expect from a blade?

if you conk it on something why wouldn't you expect it to be toast?

many years ago, about 1978, I had a lawnmower with no governor and I was reclaiming grass from the woods.

I called this thing "THE PUSH HOG"! when I'd bend the blade or bust the half moon key on the crankshaft, I'd fix it. a propane torch, a big ball peen hammer and a rock did nicely with a new key.

I see no point for any professional orgnization to do this. buy a new blade.

GEO

[David Gretzmier]

coldfiring? does this kick up the rockwell hardness of the steel in a blade to hold the edge longer? can I do this in my oven/ freezer? I am half serious. Dave g

[LAWNGODFATHER]

Done that. Been there. Watched part of the blade fly down the street. BAD idea!

LGF:blob1:

[awm]

thanks for all the advice . by the way id had a bunch of sets of blades treated . not like it cost a lot. now i just got a indestructable clean up blade.one good thing the rest of them are treated now so they probably hold there strait if i hit something.
david i think they take it to 800 degrees below 0 and leave it for like 10 or 12 hrs,then bring them up slow. and yes they do seem to hold edge a lot better .
geo ,you ought to know by now aint nothin that serious to me.
later now

[Vandora Lawn & Landscape]

You can't go 800 degrees below zero. Absolute zero is -459.67 F.

[awm]

vandora ,ill leave that for you and coldstart to work out.
my vast knowlege is that it seems to work pretty good.

[John DiMartino]

AMW,if you bend blades regularly,you might not want to treat them,or get the spindles treated too,if the blade doesnt give,guess what will,yup ,those spindles will,id rather replace a blade than a spindle any day.

[awm]

you may be right john. another thought is treating new spindles if theres enough left in the mower when they need to be replaced
later now

[coldfire]

ColdFire thermal cycling involves temperatures nearing -300 degrees F. The blade will be tougher, more wear resistant and less brittle.
The blade stays sharper longer because of a reduction in edge chipping due to a uniform and tougher structure throughout.
As far as hardness after ColdFiring of blades, the steel may increase one Rockwell point at most. But it is usually unchanged and just more uniform.
The blade AWM is referring to was bent before treatment. Although a treated blade is stronger, you should see little or no effect on severe impact bending. I would be very interested in further information on bending.
Thanks