Blade hardness question

Re: Blade hardness question

William Duffield, on the Cohansey

>Why don't you just ask Thomas Lie-Nielsen, or Ron Hock, or Jim Reed, for example, to grind and harden a custom plane blade to your specifications? Alternately, you could find a stock plane blade of the desired width, and just grind back the shoulders yourself to make it into a shoulder plane blade. With only a bit of care, you should be able to do that without heating the blade all the way to the edge, taking the temper out of it. You're going to have to do a bit of grinding on any blade to get it to fit the width of your plane body precisely, anyhow.

Re: Blade hardness question

Mike Baker

>I dont know what tool steel LN uses for their plane blades, but with most tool steels, going much harder than 55 rc will result in a blade being to brittle.(cutting edge will "chip" easily especially around knots, and figured wood.)

A2 for example will harden to 62 rc, but it is normal practice to "draw" it back to around mid 50's for cutting use.

I'm sure that the steel that LN uses is designed to have good wear properties in conjunction with its hardness grade.

If it were me .I would go with the LN blade, and keep it sharp!

Gooser

Re: Blade hardness question

Rob Lee

>Denis -

Why not use the blade from an old woody? That will most likely cost less than a new blade, and will give your plane some character...

Cheers -

Rob

Never thought about a custom blade

Denis Chénard, Orléans, Ont.

>But I'm concerned about the price tag... Remember, this is an experiment, might not work out in the end...

I thought about grinding a standard blade, but I was afraid that I might screw it up by overheating it. The idea of grinding 1/8"+ of steel on each side over a roughly 6" length flashed red lights in my head.

Still that might be the easiest option...

Thnx,

DC

Re: Blade hardness question

Denis Chénard, Orléans, Ont.

>Naaah, if I went that route and got mediocre results in the end, I would always wonder if it's because of the blade, or my workmanship. Then I'd buy a new blade and start over again...

I'm a lazy guy, so I prefer to do things once and do them right...

Interesting idea, though...

Question: can A2 steel be cut with a hacksaw?

Thanks,

DC

Re: Blade hardness question

Todd Hughes

>I'm with Rob on this one, I'd go with an nice older blade. I think scraper blades are to soft for this purpose because they are often designed to be used with a rolled over edge something you could do if they were hardened to a regular plane blade hardness. You want a blade that is harder. Best way to test it is if you can file it easly [like a scraper blade] it is to soft.Unless it has been abused I don't think you will have any problims with a high quality vintage blade ....Todd

Re: Blade hardness question

Mike Baker

>To answer your question about A2 being cut with a hack saw.

Yes, but only before hardening. Only in its normal state.

Actually a nice machining tool steel.

Gooser

Re: Blade hardness question

paul womack

>The blank (shell) that I have is 2" wide, and my plan is to build a "mega-shoulder/smoother plane".

Well, the LN #3 plane has a A2 1 3/4", 1/4" thick, Rc 60-62 blade ($35), and the LN #2 has similar, but 1 5/8" wide, ($35)

One of those sounds pretty suitable.

BugBear

Re: Blade hardness question

Mike Baker

>One other thing I would like to add.

I have on different occations, taken variouse plane blades into the inspection department where I work. (I'm a Toolmaker)

Without saying the brand names of the blades, They have checked anywhere from 57 to 62 rc. These are blades from manufacturers that claim their blades are all hardened to 62rc.

I have found that there is a trade off with the hardness of a blade.

If it is too hard, you stand the chance of it being brittle, and if you need to sharpen, the harder the blade is, the longer it will take to get a clean edge.

However, a softer blade, which I agree, looses its edge a little quicker, can be touched up faster.

I find that they will be acceptably durable (softer blades) if care is taken to really get them sharp to begin with (diamond hone the finished edge, and polish)

I'm sure there are some of you who just fell out of your chair in disagreement, Just remember, this just my HDAO.

Gooser

How hard?

jim reed @ Tallahassee

>I think RC 55 or threabouts is too soft, even though that is harder than most vintage blades. You will probably find better performance from RC58-60 up to RC63-64. Depends on other variables and is best determined by trials.

My experience with vintage blades is that their quality runs from superb (rarely) to lousy (the usual). With the outstanding steel technology available today, I cannot understand why someone would want to waste time with inferior products. Of course, I spend much of my time *souping up* vintage planes with good blades, so my opinion is biased. Good luck with your plane.

Re: Blade hardness question

William Duffield, on the Cohansey

>To further expound on what Mike said:

If you buy fully anealed A-2 from a metal dealer like MSC, then you can cut it with a hacksaw. Afterwards, however, you will have to find someone to heat treat it, to harden it, for you. It's not really economical to set up the equipment and controls you would need to harden it in a hobbyist workshop. In that way, it is different from O1, which is fairly easy to harden in the home shop or forge.

If, OTOH, you buy a pre-made A-2 blade from a plane blade manufacturer, then you will get it already hardened. It would be too hard to cut with a hacksaw, so you would need to use a grinder to cut it to final shape. You would have the same problem with a hardened O1 or other High Carbon Steel (HCS) blade from the same manufacturer.

Re: Blade hardness question

dave j

>Denis,

Just to add my 2c into the pot. I have made many blades for various tools including marking knives, chisels and planes. When I first started I found that 0-1 tool steel made some very nice blades. I have one in an old restored woody that is tapered. O-1 has some nice qualities. It is readily available in any width (including 2") and any thickness through mail order outfits. You can buy an 18" long piece and make several blades. You buy it in an annealed state and it is very soft and easily cut, filed, ground etc. It is a very stable material so it doesn't warp much during fairly crude home heat treating practices. It only requires a propane torch and some oil for heat treating (home oven helps too). And best of all it can be sharpened to one of the best edges possible of any steel. In my tests I prefer 0-1 (or high carbon) for the super sharp edge it will take and how easy it is to hand hone. Of course no steel has all of the ultimate properties that one would want. The drawback to O-1 is that it isn't quite as tough as A-2 or other steels so if you harden it much above about 60 Rc then the edge can be brittle. Having the bevel at 30 degrees rather than 25 degrees helps in this regard. Final grinding can be done after heat treating but you need to be very careful not to heat the edge. To sum up, if you want a DIY then use O-1. If you want someone else to make you one than you may want to consider either O-1 or A-2. A-2 is a tougher steel that can hold an edge a bit longer than O-1 but is a bit more difficult to get that super keen edge IMHO. A-2 requires professional heat treating and if you only have a few blades than it can be quite expensive. I now make my blades from A-2 because I wanted the consistency of a controlled HT process and I wanted a tougher edge for my chisels.

Have fun and enjoy your project.

Dave

Or Vlad Spehar *LINK*

Jorge Castaneda

>Denis,

With a good blade if the original plane does nor work, then you have the blade and the experience to make the next one work.

I suggest besides the sources already mentioned above, also considering the blades of Vlad Spehar, your paisano, I got a nice thick one from him and it is excellent.

$0.02

Jorge


Spehar Tool Works