Can stainless steel be heat treated?

[Kez]

I prefer to make my own rudder out of 1/16” stainless. I have found that a blade type rudder has less drag than a wedge rudder. The issue I have is that after silver brazing, the stainless blade is kind of annealed. If I pull hard in a turn, the rudder will bend at the joint.

Is there anyway I can restore the temper of SS?

Thanks, k

 

[Milner]

I prefer to make my own rudder out of 1/16” stainless. I have found that a blade type rudder has less drag than a wedge rudder. The issue I have is that after silver brazing, the stainless blade is kind of annealed. If I pull hard in a turn, the rudder will bend at the joint.

Is there anyway I can restore the temper of SS?

Thanks, k

What stainless are you using? Some alloys can be heat treated to increase strength and hardness. But some can't, like 303 and 304.

I prefer to make my own rudder out of 1/16” stainless. I have found that a blade type rudder has less drag than a wedge rudder. The issue I have is that after silver brazing, the stainless blade is kind of annealed. If I pull hard in a turn, the rudder will bend at the joint.

Is there anyway I can restore the temper of SS?

Thanks, k

 

[Kez]

I have no idea what stainless it is. Is there anyway I can find out?
Will it respond to oil quenching?

 

[John Beardslee]

I prefer to make my own rudder out of 1/16” stainless. I have found that a blade type rudder has less drag than a wedge rudder. The issue I have is that after silver brazing, the stainless blade is kind of annealed. If I pull hard in a turn, the rudder will bend at the joint.

Is there anyway I can restore the temper of SS?

Thanks, k

440C stainless is a very common high quality knife material and is heat treatable. I think 17-4 PH is also but I only remember when our solid shafts we made out of it and at that time they we case hardened having a 50 Rc core and then nitrided on the outside to yield a 70 Rc to allow us to run needle bearings.

 

[John Beardslee]

I have no idea what stainless it is. Is there anyway I can find out?
Will it respond to oil quenching?

You’ll need to know the alloy first. Most inexpensive knives are not heat treatable. The material needs more carbon. The better grade stainless that is heat treatable is also magnetic so you can do a simple test with a magnet.

 

[John Beardslee]

I have no idea what stainless it is. Is there anyway I can find out?
Will it respond to oil quenching?

If you do a search on line about heat treatment of stainless alloy you’ll find good info

 

[BobBrocato]

410/420 Stainless should work fine in your application, but will need to be heated uniformly to harden them. You can use a magnet to determine what type of stainless you have...400 series will attract a magnet, were 300 series stainless will not. 300 Series stainless have better corrosion resistance than 400.
Hope this Helps
Bob

 

[Kez]

440C stainless is a very common high quality knife material and is heat treatable. I think 17-4 PH is also but I only remember when our solid shafts we made out of it and at that time they we case hardened having a 50 Rc core and then nitrided on the outside to yield a 70 Rc to allow us to run needle bearings.

Hi John,
I remember when I used to run solid shaft articulated drive on one of my Dumas Drag'N Fli, the shaft was 17-4PH. If I am not mistaken, Dumas used the same material for their flex shaft. It ran needle bearings without issues. Then one time, I tried to reuse the stub shaft of a broken cable. The stub shaft became soft after brazing. That's when I realized they probably used soft silver solder to join the cable to the stub.
Thanks, k

 

[Kez]

410/420 Stainless should work fine in your application, but will need to be heated uniformly to harden them. You can use a magnet to determine what type of stainless you have...400 series will attract a magnet, were 300 series stainless will not. 300 Series stainless have better corrosion resistance than 400.
Hope this Helps
Bob

Hi Bob,
The SS i have is not magnetic. But I guess that can be anything. I read that some SS can only be work hardened like brass. Not sure how I can work harden a SS rudder blade.
Thanks,
k

 

[LohringMiller]

Our solution to the thin rudder was to use a hammer knife blade. We cut it to shape with an abrasive wheel and shimmed it to fit with glued on plastic pieces. Cutting the screw holes took diamond tipped grinding bits.
https://www.mcmaster.com/hammer-knives/
Lohring Miller