50* Inclusive Blade angle w/ 1.25mm edge bevel thickness? Too robust?

T

thesergeant

Joined
Sep 11, 2011
Messages
12
Hoping to get your guys' feedback and input on this blade. I'm hoping is salvageable but as it stands it's a terrible slicer and doesn't bite into wood well.

The blade is a 3.5" long 1/8" D2 FFG that is 1.25mm thick at the edge bevel with a 50 degree inclusive edge bevel. It's certainly a robust geometry but I'm not necessarily sure it needs to be since it's a 3.5" blade intended for 'light bushcraft/camp duty'. I can barely get it to cut paper which I'm guessing is a result of the 1.25mm thickness at the edge bevel tearing the paper apart before the actual blade edge (thanks in part to the 50* angle) can really do it's job. Every other knife I have is hair popping sharp, but I can't get this blade near that level of sharpness. Is it the 50* angle?

Do you guys think I should drop the angle to maybe a 40 inclusive or even less? Or do you think I need to make the overall blade thinner? If I can avoid thinning the blade I'd like.

Intended use is light bushcraft (light batoning, feather sticks, etc), food prep and general camp use.

Thanks!!!
 
I'd go to about half that thickness... you are at .049" and most customs are going to be around .020". 50 degrees is pretty steep too, try 40-45 degrees inclusive.
 
Daniel Fairly Knives said:
I'd go to about half that thickness... you are at .049" and most customs are going to be around .020". 50 degrees is pretty steep too, try 40-45 degrees inclusive.
Click to expand...

+1 on that!

Way too thick.

People/companies that want make hard-use knives sometimes go with thick and blunt edges, which ruins cutting performance.

Instead, focus on steel selection (choose a steel that will perform where you want it when it's at it's optimum condition, and be sure it's at that condition),
and blade design. You can have a fine edge on a hard-use knife.

If you go to regrind (which sounds necessary in this case), you'll want to grind thinner than your target edge thickness.
Let's say you want something just under .02inch thickness when you're all done. You'll be grinding your primary bevel to maybe .012, because when you put the secondary bevel on at 40-ish degrees, the remaining relevant edge thickness will be closer to .02 inch. If you grind your primary to .02 and then add your secondary, it'll be too thick again... if that makes sense. This is really evident on knives with short grind heights.
 
If 'light bushcraft/camp' includes light baton+chop & moderate whittle/carve with twisting. If so, a D2 blade at 60-63rc with 0.8mm edge thick and ~17dps (34* inclusive) would be plenty robust for such tasks.

With testing - I found D2 blades are quite strong & tough even with extreme geometry. I consider, chops with a short blade is almost meaningless since the impact/impulse force is quite low due to lack of velocity & momentum. FWIW video...
http://youtu.be/sz6OlNKRSWs
 
1.25mm at the edge sounds thick, maybe make it a scandi-like knife and put on a 2x 13degree /2x 15degree edge on
 
That's WAY too thick for a blade that size, unless you intend to only use it as a small splitting wedge.

thesergeant said:
Thanks so much for all the feedback guys! I really appreciate it. Back to the grinder it is!
Click to expand...
:thumbup:

My approach would be to regrind that blade as these folks suggested, and test it however you actually intend to use it. It will certainly cut much better, and most likely will hold up just fine unless you're doing something really extreme with it.

Then... regrind it even thinner/more acute and test it again. You may chip the edge or even break a piece off of it, but that's not a "waste" ... just chalk it up to experience.
 
You must log in or register to reply here.
Back
Top