Will 303 Stainless take and hold a good edge?

While rummaging through my garage the other day I found a box of
cutoffs I had labeled 303 Stainless. I remember buying these from a
scrap pile from a local fabricating company. Most of the cutoffs are
about 1-1/2"x2-1/2" and 5/16" thick. I have used a couple of these for
scraping in various wood and metal projects and I liked how they
worked. I inherited some beautiful pieces of hard Maple recently and I
am thinking these SS cutoffs could sharpened and used as blades in some
small wood planes. I like working with handtools mainly because my
arthritic joints need the workout. What kind of an edge will 303 SS
take just using files and stones and how well will it hold it? I don't
know enough about tempering etc. so I am hoping that further treatment
wouldn't be needed. Any suggestions are appreciated.
Dennis
Reply to
TwoGuns
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Greetings Dennis, 303 is only hardenable by working it. Even then it won't get very hard. It cannot be hardened by heat treating. It is quite soft and will not hold an edge. But it is easy to machine. ERS
Reply to
Eric R Snow
Thanks Eric. I guess I'll drop the idea of making plane blades out my 303 pieces. I'm sure I'll figure out something to do with them. . . maybe some spoons or something like that for fishing.
Dennis
Reply to
TwoGuns
It'll take an edge as well as anything. For holding one, some of the harder cheeses would give it a good run. Save yourself the effort. I suspect the scraping was done with a fairly obtuse angle, with the edge well supported. The short of it from my side, is that if it is soft enough to work easy with hand tools, it will lack in the edgeholding dept.
Best bet is to spring the few bucks for some known alloy flatstock from Starrett, like the W series (water quench for hardening) or the O series (oil). For more money you could get into the hardenable stailess alloys, but plain high carbon steel has been working great for this kind of work for centuries, and is cheap, as well as easy to heat treat. The flatstock I have seen and used came annealed, full soft, and was a pleasure to work with hand tools.
If you have to use the 303, use it for the other parts of a plane, blade clamps, trim bits, or the like. It's not too tough to work and stays shiny once it's polished.
If you are going to go through the trouble of making it, might as well make it work as good as it looks, or better.
Heat treating carbon steels is dead easy. Two steps involved. Hardening, and tempering. Heat it until a magnet wont stick to it, or until you are happy that it is red hot all the way through, plunge it into the quench bucket. Oil quenched steel will require that you not be too twitchy about flames aroung your gloves. :-) I like water quenched steel for that, and that I can get buckets of the stuff for very little outlay. :-). At this point the steel should not be able to be marked with a normal file, and is called Glass Hard or Full Hard. Top notch for edgeholding, but prone to chipping, so we want to temper it a bit to make it softer, and tougher.
You then polish the surfaces of the blade with abrasives(just to bare the shiny steel under the scale that forms when hardening) and gently reheat the blade, watching for signs of color. You can find color charts online, google "tempering colors" or "heat treating colors". Chances are good that some of those sites will have recomendations for the color you would want to reach but I figure that if you quenched it when the color first started to show at the cutting edge, you should do OK. Some guys use toaster ovens (or wait till the missus is out) to temper at temperatures of 350 - 450 deg F, with the higher temps resulting in softer end results. There are charts and info online for that too.
It doesn't need to be complicated to get great results. Lot's of this sort of heat treating has been done with a campfire. A propane torch and a couple firefricks are about as high tech as you need to get.
If you like books, The Complete Modern Blacksmith by Weygers is a good one to track down. It is the compination of two books by the same author, that gives a very easy to understand explanation of a lot of this prosess, and is a good read, too, for someone that likes to make stuff in general, and on the cheap. $20, maybe less, or hit the library.
Cheers Trevor Jones
Reply to
Trevor Jones
Thanks Trevor, I will be checking at some of the local librairies to see if I can find the book by Weygers. Using the 303 for other stuff besides the blade on a plane is probably a good idea. I did polish a couple pieces of it and it looks good even after two years. I am retired and I just tinker with things in the shop. I do make most of my Xmas presents in the shop though and I try to use scrap as much as possible. Scrounging junk piles for things that can be turned into something useful and decent looking is exciting and it fits my budget. Heck it has even put a few beers in the fridge at times. LOL. Dennis
Reply to
TwoGuns
I realy like that book too. A knifemaker frien of mine used to use old cooking oil to quench with. He said it didn't flare up nearly as much as regular oil. Karl
Trevor J>
Reply to
kfvorwerk
It's not the be all to end all, but it has clear enough explanations that it takes quite a bit of the fear out of delving in.
Cheers Trevor Jones
Reply to
Trevor Jones

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