The blade of my #4 plane is slightly warped; it rocks when laid on a flat surface. It is made of A2 steel.
From an article on hand planes by Ian Kirby:
If the iron is bent along its length, straighten it by placing it over a block of softwood and bending it in the proper direction. Put the convex side up, and strike the iron sharply one or two times with a steel hammer.
Will this work on an A2 blade? I am not sure if it was used in planes when FWW #35 was printed. I am not worried that A2 is too hard to be bent, because then I’ve just wasted a little time with no harm done. However, the blade has lost a tiny chip from one corner, which could indicate brittleness. Will the blade break when hammered?
Janet
Replies
How Come ?
What caused it to bend ? If it came to you bent from the plane blade maker perhaps it would be best to have them warranty it.
A couple of more thoughts:
1. If it warped in heat treating BEFORE it shipped out it is going to be pretty difficult to tell where and how much to bend it to get it flat if you don't work with metal much. You need to take it past it's elastic limit into its plastic range. That means it is like bending a very thick spring. You may get a lot of exercise but not much bend.
2. If you get lucky it was bent from trauma to the blade AFTER it was heat treated. Steel has a memory and it may not take much to bend it back to where it was before the trauma. Hoping that it was originally flat then.
In this book
http://www.amazon.com/Japanese-Woodworking-Tools-Tradition-Spirit/dp/0941936465/ref=sr_1_1?ie=UTF8&s=books&qid=1306373577&sr=8-1
they make a habit of hammering the blades in the area where the bevel is. The Japanese blades have a large area at the bevel because the blades are twice as thick as the Western blade you have. There are no harder blades than the Japanese blades but they are layered with milder steel to make them resistant to cracking or braking.
How about those apples ?
What to do with your A2 plane iron
Janet:
Is this a fairly new iron and who was the manufacturer? I would call them and get a warranty replacement if at all possible. I have purchased some old Stanley planes that came with bent irons, but the Stanley Bailey plane irons were thin to start with. Without seeing the article, I'm guessing Ian Kirby had either a Stanley or Record plane iron in mind when he wrote about straightening plane irons. If you are determined to whack away on it, the iron should bend before it breaks, A2 is not that brittle. As for the chip in the corner of the cutting edge. This is somewhat normal with a new iron. Due to the nature of heat treating, many of them come from the manufacturer with the initial bevel being brittle. When you get one of these you just grind it back and form a clean edge (grind first at 90 degrees until you are past the chip and then set your rest to the bevel angle you want to end up with).
gdblake
Bending A2 blade
Hello,I am retired master tool maker at Colonial Williamsburg. Having used a lot of A2 in our home business,I strongly advise you to NOT attempt to straighten it. How brittle it might be depends upon how it was hardened,and especially how it was tempered.
If you can return the blade for a better one,do so. Once you break it,you will be stuck buying a new one.
I have straightened many hardened tools,but you have to know what you are doing,especially with the more sophisticated steels such as A2.
What can be done is to place the blade in a 400º oven until it is thoroughly up to that temperature. Getting an accurate temperature is the first problem. Kitchen ovens and toaster ovens are not extremely accurate. Kitchen ovens can be 75 degrees off in either direction. I use a toaster oven with a long shanked high temp. thermometer from Brownell's Gunsmith Supply inserted into it. Be careful,you can ruin the thermometer if you touch a live wire in the toaster.
Once you have this rig set up,place the blade inside and heat to 400º for 1/2 hour. while the blade is STILL HOT,you can quickly place it in a vise and bend it straight. BUT,if you let the blade cool much at all,you can break it right off,so work fast. I advise using wooden jaws. They may scorch,but you can replace them. Steel jaws will suck the heat right out.
Heating the steel to 400º will not hurt the temper,as that is the correct original tempering temperature. Sticking an iron in a kitchen oven that runs too hot will certainly draw the temper softer,which you do not want. And,once you do that,the iron is messed up unless you can get it completely re hardened and re tempered,so,DO invest in the high temp. Brownell's thermometer.
I have made many,many tools like reamers,which very frequently warp upon quenching. I have been able to bend them like a spring WHILE they are hot. When they cool off,they would shatter like glass.
The procedure I have given is standard practice among tool makers,file makers,and knife makers for straightening warped tools.
Bravo !
Mr. Wilson,
That was Great !
That's the stuff I hang around here for.
Exceptional craft people doing fine craft and sharing some of what they can.
Roc thought you might enjoy this,
Neander interview: George Wilson
Yes ! Thanks !
There is some great reading in your post. What a post. I still haven't read ALL of it yet.
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