Ah hae me doots!

[Seagull]

Being temporarily chokka with leatherwork, I took inspiration from a recent thread on the making of a knife from a sawblade.

Never having tried anything like this, and certainly not in dire need of another blade, it was more idle curiosity that made me set about a defunct blade from my Mountfield mower.

Initially, I had hoped to tackle the cutting out ,with a Dremel lookalike, and I progressively worked my way through most of it's tools, consuming 14 thin discs , 3 thick grinder discs and destroying two drive spindles.

Must be pretty hard stuff, thought I, as I resorted to using a hacksaw at 32ppi. and by golly it took some time with this.

Eventually cut to shape, sort of, I started with the file and this is when I noticed that in the shaping of the bevel, I was creating one whale of a feather-edge, and this didn't seem right, not after all the effort of cutting it out.

An impromtu run with the oilstone, showed that , yes, it was poss to make a shaving edge, it also gave a very fragile and large feather edge which had to be stropped off.

Not knowing what type of steel this is, didn't deter me from cooking it up at max heat in the fan oven , for 30 mins, then quenching in motor oil.....and everything when a fetching shade of coppery brown.

Now, after that lot, it dosn't seem to want to take much of an edge.

I'm rather doubtful of investing what could be quite a lot of time, in finishing this, handling it and making a sheath for it.

Still, it was a good excuse to create a bit of noise, mess and chaos.

Anyone used a mowerblade, with satisfactory results? I wonder.

Ceeg

 

[NatG]

when you heated it up and then quenched it you probbably didn't heat to the right temperature or quench in the right medium.

perhaps ask them on www.britishblades.com

they know a thing or two about pointy sharp things

 

[Draven]

I doubt an oven would get it hot enough... generally speaking it needs to be a cherry red, which is upwards of 950 degF (510 degC).
HT heats and such will depend on the type of steel, though..

 

[FGYT]

i would doubt a mower blade if even teh right steel would be hardened like a saw blade as you dont want to hit a stone and have it shattter etc
most mower blades ive seam dent and score easily

put the rest in a vice and see if it bends (warning it may shatter but i doubt it )

additional tempering would only make it softer

it still may be good steel for a knife but will need proper hardening first

ATB

Duncan

 

[SOAR]

Alot of mower blades tend to designed to bend when they hit something hard or big enough to stop the rotation of the blade, they are made this way as a preventitive measure to stop the crank shaft from breaking as its cheaper to buy a new blade rather than have to buy a new crankshaft. Honda do this but some of them have a sheer bolt on the crankshaft so if they get under strain the sheer bolt will go first. Not too sure about Mountfield. Good luck with the knife.

 

[Tadpole]

from a quick look on the net, it seems that mower blades come in three flavours,

Tool steel. mucho expensive and very hard to sharpen. (rare to find on anything but huge expensive machines, the blades have to be sent away for sharpening)

Boron Steel, again rare, but getting more common, it's a low carbon steel that has been case hardened and treated/made with a small amount of soluble boron

Mild steel. very low carbon content and very common in mower blades
mild steel is soft and cheap, it will sharpen, but will not keep much of an edge. repeated Carburization, (dunking the really hot metal in to carbon bearing substance) will help retain some wear resistance, but over all I doubt that it is worth it, when you could buy a knife blank or a 12"x20mmX3mm of 01 tool steal for under £20
YMMV

 

[Shinken]

well several things could have happened here, the going at it with dremel could have softened the steel, if it was properly hardened a file should have slid over the surface.

its much better to anneal steal first, that is if you know what it is and know if its anygood

my advice is buy some 01 from cromwel already annealed and have a go with that then get someone to ht for you or have a go yourself.

do a search for greenpete too

 

[spamel]

Don't give up. Go to British Blades and start a thread. You will get advice and help, and I'll bet one or two people will offer to HT it for you. If they do, send them the other bit of the mower blade for them to try on before they try your blade. I love the way you have used the spindle hole to put the ricasso on, saves a bit of work! It is a really nice shape on that blade and would be a waste to bin it after all of the work you have piut into it.

Please, give the BB lot a try before you try to destroy your hard work.

 

[Seagull]

Thanks for all the input, fellah's; much appreciated.

This mower blade,is just a light-hearted messing around with something that would otherwise have gone to the skip.

But some aspects of ,"just messing", has got me me intrigued.
F'rinstance, Ive had the grassblade for 12 years and never needed to change it, til recently and its replacement was very difficult to track down. During this 12 years, I've sharpened it with files and carborundum stones, but once a year; and its always been a right bogger of a task.

I never once in all that time, bothered to clean off the damp grass and the undermetal just used to go black, with hardly any rust and little pitting.
It was really difficult to cut through, when shaping the blank and, today, I did some sort of comparison test, in terms of work and effort........and I find that the blade as is now, is just about as difficult to work ,with stones and files ,as an old pair of Bonsai root shears which I rarely use..

Another thing, I spent almost 2 hours with the 3 Lidl diamond stones, in trying to remove some of the heavy filing marks, very hard work and nowhere near good enough.

I also did some cutting tests, first on the inner pages of a phone book.....very good, but lost it after about 20 cuts. Then on to 5mm leather, it just kept on slicing a 3 inch strap, 40 cuts before it got difficult.

As an experiment, it puzzles me in a few things, not least of which, is the curious property that it never feels really sharp since I baked it, and I have yet to get any detectable feather edge???????????.

I think I will just have a word with my bro, who has the practical ability to HT and, see if it worth continuing with.

Thanks again fellah's and if anyone out there could rationalise some of my findings, I would be glad to know.

Ceeg

 

[spamel]

I reckon you have good steel, but it just needs re-HT'ing. The blackness on the blade you mention sounds like a good patina to me, that will stop the rust. I hope you get it HT'ed and it works out well, it sounds like you could have made a good blade here, and there seems to be enough mower blade left to make a second one. Maybe a twin that you could give to your brother so that you both have the same knife. That'd be cool because it will have been made by the both of you, a real collaboration.