large cpm 20 cv blade .. need some guidance

[timos-]

I have a pretty big K-Tip Gyuto I am working on. 10" blade, 4mm thick stock.

There has been several threads recently debating how to most efficiently finish out knives with regards to abrasive costs and of course time.

I would like to take the blade to finish size pre heat treat to save time and belts. also I need to have a needle thin tip on this that can ghost right through an onion, and only about .005 behind the edge. the bevels are symmetric ground with a 48" radius platen.

For those guys that do their own heat treating how much of a nightmare would this blade be to harden and keep straight? Keep in mind there would be no parallel or even flat surfaces on this knife.

I would ask directly but the heat treating guys are so slammed with work.

 

[tim37a]

Brad at Peters wants .010 edge minimum. That's what I send him and they always come back straight.
Tim

 

[timos-]

Yah I will have to finish the bevels post heat treat to some degree, I am more wondering about the distal taper ie. not being able to put between plates.

 

[Willie71]

I've used shorter plates and clamped the largest flat surfaces and not worrying about the tang. Try carefully placing the blade between the plates which will form a wedge or v shape rather than being parallel.

 

[Darrin Sanders]

I find 20 CV easy to grind after H/T so that's what I'd do. As for keeping it straight during H/T with no parallel sides to keep everything straight? Probably not and without parallel surfaces to draw heat into the plates you wont get a good quench either.
I'm not trying to be rude here but I just can't figure out why you have so much trouble grinding hardened steel. I grind high V steels after H/T all the time and after that, 20 CV feels like butter.