Angles

[dtalbot]

Hi All,
What sort of angle should there be where the two sides of the blade meet at the sharp edge? (sorry if these things have proper names I'm still to learn them). My first sketched design come out at about 16 degrees
If it makes a difference I'd hope the first project to be a general outdoors knife so bits of eveything to do from cutting wood to skinning rabbits.
Thanks
David

[Colin KC]

David, the achul edge of your knife prolly needs to be @35-40 degrees included, meaning from one edge to the other (or, a "v" sign with the fingers;))

Hope that helps

Col

[dtalbot]

David, the achul edge of your knife prolly needs to be @35-40 degrees included, meaning from one edge to the other (or, a "v" sign with the fingers;))

Hope that helps

Col
Just the thing I needed to know thanks. Is there a good book put there that covers all the daft questions I keep bugging you guys with?
Cheers (with a large glass of red in hand :) )
David

[PS_Bond]

*A* book?
Probably not...

Possibly the most useful at this stage of the game is Wayne Goddard's $50 Knife Shop. There are several others too - Jim Hrisoulas, Tim MacCreight, Loveless & Barney, David Boye have all published books on knifemaking. Do a search, you'll find that several of us have wittered about most of them at some time.

[dtalbot]

Ta,
The first one is already on my birthday wishlist so I guessed right there! Still at that stage where the more I learn the more I think about the subject and realise far more things I don't know
David

[Martyn]

I'd say by far the best think to do is to "keep bugging with the daft questions" - cos they're not daft if ya dont know the answer and there are many, many people in that position. It all adds to the searchable knowledge base on the forums. :)

[shing]

David, i got a stack of knifemaking books you're welcome to borrow when you pop down including the Goddard, Loveless, Fowler, Hrisoulas and Lake

[Kevin]

Hi David.

I dont usualy think of angles as in degrees, ......I make a knife and can pretty much eye the angle I want.....depending what the knife is intended for.
I then go and use/test it to see if it will do what I wanted to do.......


However......Here are some angle guides from some literature I have to hand...keep in mind that these are guidlines for putting secondary bevels/cutting edges on. and this is only a general guide...
If its a single bevel to edge profile then the blade edge may be more fragile and so I am guessing adjustments may need to be made :)

13 degrees......... delicate work , slicing.
15 degrees.......Thin kitchen knives?.....
17 degrees..... most general purpose kitchen knives
19 degrees.....Thin pocket knives and kitchen knives for heavy work
21 degrees.. pocket knives and thin hunting knives
23 degrees....hunting knives,chopping knives.
25 degrees.... thick blades

[PS_Bond]

IIRC, my Bison Woodsman is somewhere around 22 degrees, and that has no secondary bevel. 4mm stock, too.

[ZDP-189]

Hi All, What sort of angle should there be where the two sides of the blade meet at the sharp edge? (sorry if these things have proper names I'm still to learn them). My first sketched design come out at about 16 degrees If it makes a difference I'd hope the first project to be a general outdoors knife so bits of eveything to do from cutting wood to skinning rabbits.

Hi Dave,

Welcome to the forum. :biggthump

First some terminology; it differs between people and even from conversation to conversation. By 'edge' I mean the final angle where the cutting action happens. By 'relief' I refer to the angle that the edge is ground into, be it the blade face itself or the bevel. 'Bevel' means the sloping cut into the blade face that narrows the blade to the edge. I guess the angles you and Coutel are talking about are measured from centreline to surface. Double these angles to get to my units which, Like colin measure from one side of the V to the other.

Any acute edge angle between zero and 90 degrees will cut. How it cuts and retains its edge depends on that angle. Narrow angles will slice keenly but lose the edge quickly under hard use unless a very hard and strong steel is used. The steel and the knife's intended use will determine the optimal blade angle.

Most sharpening gurus seem to like an edge of between 25 - 40 degrees for most puposes. Personally, I favour the low end, but then I also like to sharpen - a lot. I guess a good general purpose blade for your use will probably be about 30 degrees. To get that you should probably subtract 10 degrees to set your relief.

Actually, aside from metallurgy and tempering, there are two key secrets to making a sharp knife. The first is relief. A very narrow relief angle means the final edge will be easy to create and makes for the keenest of cuts. I find this angle is more important that the edge angle in most applications (especially soft materials), because the resistance to the wedging effect comes from the relief, not the edge. I imagine the drawing you have made illustrates the bevel which in most designs the same as the relief. This is the angle that the smith grinds into the blade for you, not the sharpening angle you put on with a hone before use.

The second secret is to maintain absolute control over the edge angle so that the hone doesn't round the otherwise perfectly sharp edge. This sounds simple, but it's next to impossible without a mechanical guide.

If you're looking for a book, try John Juranitch's book, available from his company or any on-line bookseller. Otherwise, search this forum - a lot has been written here!

http://www.razoredgesystems.com/images/BK10.jpg

Link (http://www.razoredgesystems.com/index.php?cPath=25&osCsid=0faf9c546200efdf68db2289e1f73cb8)

[dtalbot]

David, i got a stack of knifemaking books you're welcome to borrow when you pop down including the Goddard, Loveless, Fowler, Hrisoulas and Lake
Thanks, I'll take you up on that one! and as you've no doubt guessed I'll be picking your brains a bit when we meet up :)
David

[dtalbot]

Thanks all,
I think I'm getting my head round things now, The Bison Woodsman sounds as though it will be a good guide as looking at the pic on their website it is pretty similar to what I'd got in mind.
Cheers
david

[shing]

Sure David,

I've got a couple of blades that I will heat treat at the weekend, if you want to come along to that, it'll be after 8pm, let me know.

[dtalbot]

Thanks Shing,
Yep seeing someone who knows what they are doing do the heat treatment will be a big help. I;ll give you a ring Saturday afternoon just to finalise the time.
Cheers
David