1095 fully hardened?

M

MCoughlin

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Feb 1, 2005
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I am making a knife for my brother in law who is joining the Canadian reserves. I'm wondering what some of your thoughts are on whether to fully harden or to do some clay coating to keep the spine a little softer to prevent breakage.

... I understand a military knife gets put through some heavy work and I don't want it to bend but I also don't want it to snap.:confused:

The blade will be around 7" or so.

Any thoughts?

Mike
 
You could do clay, or just harden it fully, temper normally, submerge the cutting edge in water and heat the spine up to a deep blue with a torch.
 
1095 will form a wicked hamon with a clay coat. To do the simple type of hamon:
Coat the entire blade with a thin coat of slurry ( a fairly watery mix of Satanite and water). Allow to dry. Coat the entire blade with 1/8" of satanite. Take your fingers and wipe off the clay from the edge of the blade, going back about 3/8". Let dry completely (you can speed it up with a hair dryer or a torch). Austenitize at 1475 for 5 to 10 minutes. Full quench into fast quench oil ( I go tip on all at once), and pull out after about 8-10 seconds. If the clay is still attached, quickly scrape it off ( don't knock it off!) and check for warp/twist. Correct immediately while the blade is still between 400 and 900F. Cool blade in the oil, clean, temper at 400F twice. This will give you a pearlite spine (soft and tough) and a martensite edge( hard and tempered).It will take a sharp edge that can be touched up in field easily.
A quick dip in FC will show how bold the hamon will be.
To finish the blade, sand to 1000 grit ( hand sand above 400), etch, wet sand to 2500. It will show a lovely hamon.

If you properly clay coat the blade and do the full quench, there would be no need to draw the spine to blue color while edge cooling the blade in water, as pearlite is already soft.

The edge in water trick is for blades that were fully quenched to martensite and then you are drawing the temper back to a pearlite mix by overheating the spine. I find the results better and more predictable using clay.
The two techniques often look similar but one is a quench line and the other is a temper line. The difference can mean a lot. A clay coat has martensite going up into pearlite, a temper has pearlite descending down into the martnsite. It is not a problem if the martensite goes a bit farther into the pearlite, it can be ruinous if the pearlite goes too far into the edge.
Stacy
 
I wouldn't bother with a hamon, but it might be wise to soft back it in water as mentioned.
 
Fully quenching the blade and then drawing back the spine will give you the highest levels of toughness along with strength, and you will not have to worry about how much of that pesky soft stuff got down into your critical edge area like you would with a differential hardening. As has been pointed out a really pretty, shaped transition line between martensite and pearlite will be pleasing to the eye but will offer no real advantages in edge hardness, or overall strength of the blade. The full quench will also offer you more complete control over the process.

Lots of good advice in this thread, including the idea that 5160, L6 or some other alloy may be much better than 1095 if toughness is critical.
 
I'de stick with the 1095 if you are familiar with heat treating it. Would either fully quinch/draw as Kevin says, or put a very "high" line on it, as in just cover the top of the spine with clay (if you must tinker with the clay).

If your just trying to make a good tuff knife and the appearance of a hamon arent really a benefit, than dont bother with it.

As far as performance, ide take 1095, W2, 1086M over L6 or 5160... but thats just ME and what im familiar with (familiarity with what your working with is way important and way overlooked).
 
We can take things beyond personal preference if we get more specific about "performance". For toughness at equivalent hardness the L6 is going to win hands down over any 10XX series or W2. While the W2 is going to trump both the L6 and 5160 in abrasion resistance and edge holding. Of course this does all rely upon the familiarity aspect, or more accurately the knowledge and ability to maximize the potential properties of the steel.
 
Kevin, I have a question for you (or anyone else who can help), about the relative performance of different steels, but I don't want to hijack this thread, so I'll start a new one. Please check it out, thanks.
 
Well I don't have a torch in my garage/shop so I will do a "higher" hamon as mentioned with clay. Changing steel at this point is not an option so I will be making the best of 1095. I am familiar with the methods mentioned so it shouldn't be a problem.

You guys gave me some very good info and I thank you very much. I especially found the difference between a hamon and a temper line Very interesting.

Mike Coughlin
 
1095 steel has been used for many service knives, including KA-BAR and Ontario Knifes. I've always done an edge quench in oil and temper in an oven with no problems. I'd recomend to Parkerize or phosphate the blade even though my first knife is of 1095 (unparkerized) and it is still in service with no rusting.
 
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