Heat Treating question

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GaryPogueCustomKnife

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Oct 8, 2013
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I just picked up a sawblade made from L6 steel. I have the knife almost ready for heat treating. its roughly between 3 and 3 1/2 mm thick. Please shed some knowledge on this thread :D
 
Are you sure it's L6 ?? Lots of people assume saw blades are L6 but few are !
 
I agree with mete. We've used a lot of sawblades of various sizes and types and the ones we've had tested by metallurgical labs were 15n20, high chrome high nickle 1075, and 1095.

~L
 
15N20 or L6, the HT is the same.
Never use a torch or forge to HT these steels.
Pre-heat in an oven to 1200°F and equalize for 10 minutes. Raise evenly to 1475-1500°F and hold for 10 minutes. Quench in medium speed oil. Temper at 400°, twice.
 
Stacy, is it because of the nickel in the 15n20 that you recommend the same heat treat as L6. I thought it was the chromium in L6 that made the heat treat more complex. 15n20 looks to be 1075,with 2% nickel. It seems people polarize the recommendations, either treat it like 1075, or treat it like L6.
 
The recommended HT for both is virtually the same. What you DON'T want to do is soak it for too short a time, or have poor heat control. If there is any doubt of the steels actual composition (which there often is), just use the mid-line HT I posted.

I have given up arguing that L6 and 15N20 are pretty much the same thing ( which is part of why all big circular saw blades got dubbed L6). Many people argue that they as opposite as 1084 and 52100 .... I don't see the difference as that big.

The chemistry is "close". One has a bit (more*) of chromium, one has a bit less nickel, otherwise they are virtually same. Alloying varies from batch to batch, and foundry to foundry, but the below info is average.
L6 - 0.75C, 1.75Ni, 0.75Cr, 0.40Mn, 0.50Si, .20V*
15N20 - 0.75C, 2.00 Ni, 0.10Cr*, 0.40Mn, 0.30 Si,
* found in some formulations.
Here is a comparison graph:
http://zknives.com/knives/steels/steelgraph.php?nm=15N20,L6&ni=,140&hrn=1&gm=0
( move your cursor over a graph line to see the details)

With the proper HT, both steels will make a great knife. Some feel L6 a bit tougher, some feel 15N20 is finer grained. Personally, I doubt you could tell one steel from the other in a well made knife.
 
I use known 15n20 from Canadian knifemaker. I just ordered some thicker 15n20 from Aldo as well. I will hold it at 1480 for 10 minutes instead of 2-4 in future. HT is quite similar to O1 then. I have found 15n20 to take a pretty fine edge. I am really liking it. Having a steel in 0.065" is handy for slicing knives.
 
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