View Full Version : wood plane iron (blade) questions (and intro)

12-19-2006, 02:13 PM
First post here - I've lurked a bit over the years, but gotta ask a few questions.

I'm more of a woodworker than metalworking (mostly due to lack of equipment). On a woodworking forum, we are looking to make some plane irons for cheap so that the members can make their own wooden planes kind of like this pop mechanics wooden planes (http://www.popularmechanics.com/home_journal/woodworking/1273456.html)

Anyway - seems that the 2 popular choices for raw stock are A2 and 01 tool steel. Preference for this project seems to be 01 as it is less expensive and supposedly easier to sharpen once hardened. Looking to use 1/4" thick stock in a variety of widths (up to 2"). Questions are:

1. Can we just cut rectangular blanks, have them heat treated - let the plane maker's grind a bevel on it afterward (assuming they are using a wet grinder or are very careful not to overheat the blade)?

2. Is this steel machinable with conventional tooling or is carbide required?

3. Can the blanks be cut to length with a bandsaw?

4. Recommendation for heat treating facility that will do small lots for short money (or if any of you have ability and would like to work in exchange for a few of the blades and/or $$).

Thanks in advance for your help

Your Old Dog
12-19-2006, 03:21 PM
There will be others more qualified to answer your question then me but here's what I would suggest.

I'd go with 0-1, rough grind them and then heat treat them yourself. I'm not sure why you are using 1/4" thick blades as most that I'm aware of are 1/8" and much easier to heat treat at home. As a rough approximation I would heat treat 1/8" thick stock with a Berns-O-Matic type propane torch in a darkened garage to cherry red and hold it cherry read about 5 minutes. Then I would sink it into a coffee can full of 10 weight Pennsylvania non-detergent motor oil.

You can get as complicated as you want but just remember, there was a yesterday and they didn't have and or need all the fancy stuff at hand today. I think you will enjoy the project more if you do it all yourself. O1 should work fine with files and regular grinders and drill bits before it is hardened.

If you just sink the metal into the oil and don't swirl you won't have to anneal it as the hot oil forms a jacket around the steel and it's self-annealing. If you swirl the metal in the oil it will cool much faster, become harder and then you will polish it silver and then heat it till you see the traditional straw yellow and then quench it once again. This really ain't hard and should work well for your modest needs.

If you haven't found the metal yet I've had pretty good luck at http://www.use-enco.com/CGI/INPDFF?PMPAGE=632&PMCTLG=00 . No connection, just satisfied customer.

good luck,

Frank Ford
12-19-2006, 03:24 PM
Offhand, I'd be inclined to do it all myself. For my woodworking tool making, heat treatment isn't exactly rocket surgery. I just use O-1, cut it to shape, heat with a propane torch until it becomes bright red and nonmagnetic, dunk it in used motor oil, and cook it in my kitchen oven for an hour at 400 degrees to temper it.

That gets me a pretty good tempered blade, and it works well for me. For sure, I won't be causing Ron Hock any sleepless nights, but I figure my homemade blades work well enough, and may only need to be sharpened a bit more often.

As for cutting, 0-1 works well with bandsaw, hacksaw, file, or whatever. I think I'd establish a nice bevel with a belt sander before hardening - that way the kit maker would have a headstart on sharpening.

12-19-2006, 03:40 PM
You won't be able to harden the entire piece using a torch -- you won't be able to get it uniformly hot enough -- but you don't need to. Just harden the cutting edge for about 1/2" back and you'll be fine.

I'd basically agree with the others. O-1 will be fine. Rough-grind a bevel first. You may want to use some Keep-Bryte Anti-Scale Compound when hardening (MSC www.mscdirect.com sells it, as do other) to protect the surface, but it's not strictly necessary. I'd use hydraulic oil for quenching, #10 if you can find it, but as Frank says, it's not rocket science. I'd probably temper at 350 degrees in the oven, not 400, but again, it's not magic. Do a few samples and see what works best for you.

You won't need carbide -- assuming you're machining the un-hardened stock.

A bandsaw will cut the stuff.

O-1 stock is available all over the place: MSC (mentioned above), McMaster-Carr www.mcmaster.com , ENCO www.use-enco.com I think, and others.

If you don't want to heat-treat yourself (which you may not, as you want a guaranteed result every time because these things are being sold), try looking up heat treating in your local yellow pages. Odds are they'll take walk-in jobs, and as long as you can wait for your parts to be done the next time they have an O-1 batch going through their ovens, the cost shouldn't be too high. Or search the internet...

12-20-2006, 09:40 AM
Thanks for all the great info. One last question - can I cut the stock with an abrasive chop saw? Or would the heat involved do damage?

To answer the question about the thickness, thicker is supposed to give better performance, we are planning to skip the "chipbreaker" which is typically used with the thinner blades to add support and minimize chatter. Maybe 3/16 would be a good comprimise...

12-20-2006, 10:46 AM
Either steel will produce a plane iron that will take an edge and shave wood paper thin but the A2 will air harden and you won't have to worry about the quenching process. Definitely google up heat treating recommendations for either steel as 01 varies in composition depending on the manufacturer. I have about 4 or 5 pieces in stock from England, Germany, Sweden, and the U.S. and they often have small amounts of other alloying metals in them. I like the 01 from Uddeholm Steel for no other reason than it's Swedish and Randall Knives use it for their carbon steel blades. Those aren't totally rational reasons.... If you buy a small piece of 01 or A2 from Enco, Victornet.com or elswhere, the composition and heat treat instructions will be on the wrapper. One trick I use to save money is to look at the Specials. Usually you can get an off-size piece for half the price and I don't mind getting a 5/16" thick piece for half the price of the more popular sized 1/4" pieces.

You can grind the bevel after you heat treat but that really eats up belts and it's easy to get a blue spot which means you have to re-heat treat. I recommend grinding the bevel before you heat treat. I do that with the knives I make and it's pretty standard practice among knife makers. Finish your plane iron edge on a 4000 grit and then an 8000 grit stone such as the Norton waterstones or the belgian natural waterstones (www.theperfectedge.com) and you'll be shaving sharp in no time.

You can cut the flat stock with a metal cutting bandsaw and I love the bi-metal blades I get for my old Kalamazoo. Cut the stock before you heat treat or you'll eat up expensive bandsaw blades. Milling 01 or A2 is no problem either with regular HSS end mills. Life on them will be prolonged if you spray some oil on them to keep them cool. Micro-mark sells an inexpensive unit for squirting miscible oil on the work. I'm making one now out of a magnetic dial indicator holder (sans the indicator), a salvaged pump from one of those tabletop meditation fountains, and an old oxy-acetylene tip for the squirter end. Let you know how it works out.

Quenching Oil - if you use corn oil, your shop will smell like cookies baking when you heat treat. I throw in a quart of Harley Davidson motor oil to keep the critters away from the oil. I also have a red 5 gallon, hinged cover bucket of regulation quenching oil and if you do a lot of quenching, that's the way to go. The bucket also has a handy basket in it to retrieve dropped parts. You want to avoid fires. One young blacksmith around these parts cut his quenching (motor) oil with gasoline and promptly burned down his garage and then the house. Really teed off his wife. Don't fool around when it comes to 2000 degree hot steel and liquids that can catch fire is my recommendation....

I strongly recommend you try heat treating as it will give you an added appreciation for that dimension of metal work. It's not hard to learn how to do it but there's a lot to learn to get consistent results.

Have a happy holiday and safe, healthy, and prosperous New Year.