heat treat question

[Gunnyart]

Alight knife guru's

I don't have a heat treatment oven so I stick to 1095 for simplicity.
Today I made (stock removal) an 8" chefs knife and spent all day doing the flat grind and distal taper on my little 1x42 delta.
My fear is that such a long thin blade might warp badly with my normal procedure.
Would you recommend an edge only heat with a torch or perhaps a differential where I heat the whole thing but the spine stays out of the oil?

Thanks,Art

[Razorback01]

I've done about the same length 1095, more of a filet profile, with no warpage. It went completely into the oil.

[coachk]

I hard grind all of my kitchen/filet knives so I dont have to deal w warpage much at all. if it warps you can straighten it during tempering, just a PITA

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[CWendling]

2 things. First, 1095 is not (unlike many bushcraft sights will tell you) a simple HT steel. For that, stick with 1084/1075 where you heat to austenize temp and quench. You can do this with 1095, but to get the most out of 1095 it requires a soak at temp. Second, for any thin knives like kitchen/filet I will always recommend HT first, grind after. Warps can always be an issue. Normalizing, even a stock removal blade, can help sometimes.

[CWendling]

I would do a full quench at this point and fix any warpage if it happens. An edge quench will generally lead to more warping on thin stock

[Gunnyart]

It went well. In the tempering oven now.

I themo cycled a couple time then brought it to non-magnetic and held it there for a minute before quenching in canola. I intended to keep the spine out of the oil but without thinking I plunged the whole thing in. I had a very minimal warp the came out easily with a little pressure before it fully cooled. Pics to follow.

[SamHarper]

I've had such bad luck with long thin knives warping in the past, that I've changed how I do kitchen knives altogether. I heat treat them before I grind the bevels. I quench them in oil for seven seconds, then stick them between two slabs of aluminum and hold them together for about a minute. They come out straight or nearly straight every time. It just takes a little longer to grind the bevels since they are hardened.

If I were you, I'd quench the whole thing in oil for ten seconds or so, then stick it between two slabs of steel, wood, or whatever you have, and hold it there until you think it's cooled off. If you have any warping, you can easily fix that during your second temper cycle. Do one temper cycle, then on the second one, clamp the blade up against a piece of angle iron or something with maybe a penny or something to correct the warp, and do a second temper cycle. This should fix any warps. If there's still a warp, do a third temper cycle. It won't hurt anything.