MEMBER ITEMS FOR SALE
Custom Knives | Other Knives | General Items
-------------------------------------------
New Posts | New PhotosAll Photos



Go Back   The Knife Network Forums : Knife Making Discussions > Custom Knife Discussion Boards > Knife Making Discussions > The Newbies Arena

The Newbies Arena Are you new to knife making? Here is all the help you will need.

Reply
 
Thread Tools Display Modes
  #1  
Old 09-15-2017, 06:02 AM
Rasmus Kristens Rasmus Kristens is offline
Steel Addict
 
Join Date: Jul 2014
Location: Denmark
Posts: 165
Relation between primary bevel angle and secondary?

Hi

So far I haven't though about relations between the angle of the primary bevel and the secondary. I'w alwayse just made a primary angle that fit my taste and the blade.

I ususally do a 25? secondary bevel.
I did try a 20? on 2 knives that made the secondary bevel look quite large on the blade, since the primary bevel were shallow to start with.





Is there some rule of thumb on some angles that go well together?
Does it have any influence on the cutting capabilites on the knife?

Last edited by Rasmus Kristens; 09-15-2017 at 06:49 AM.
Reply With Quote
  #2  
Old 09-15-2017, 07:17 AM
Ed Caffrey's Avatar
Ed Caffrey Ed Caffrey is offline
Super Moderator
 
Join Date: Jun 2002
Location: Great Falls, Montana, USA
Posts: 4,254
Send a message via AIM to Ed Caffrey Send a message via Yahoo to Ed Caffrey
Personally, I don't like/deal with specific "angles"..... each knife I build gets a geometry that is intended to minimize cutting resistance. The vast majority of my blades are flat ground, with a convex edge. The amount of convex utilize on the edge(s) is dictated by the end use. For example, those blade intended for fine cutting jobs such as hunters get a fine convex on the edge, and those blades intended for heavier use such as camp blades or others that will see chopping/harsh duty, get a heavier convex. The geometry/grind is only a small part of a blade.... I also consider the steel being used, the hardness level, and try to anticipate the expected use(s) of the blade. In other words the blending of all those to achieve the best cutting tool I can produce.

That being said, one of my primary considerations is minimizing the cutting resistance of any blade I produce. Generally, the smaller and shallower the cutting edge bevels, the less the cutting resistance, while the more obtuse and and larger the edge bevels, the more cutting resistance.

Probably the best advice I can offer, in order for you to see/understand, is to cut various materials under heavy magnification, and actually see how various geometries/edge bevels cut through material..... those edges with larger, more obtuse bevels will in many cases literally "wedge" into whatever material is being cut.... requiring much greater force to cut through a given material....and in some cases of very obtuse edge bevels, a blade will actually tear material, rather then cut it.


__________________




Caffreyknives@gmail.com
"Nobody cares what you know.....until they know you care."
See me at table 2Q at the Blade Show!
Reply With Quote
  #3  
Old 09-15-2017, 09:01 AM
Ray Rogers's Avatar
Ray Rogers Ray Rogers is offline
Founding Member / Moderator
 
Join Date: Jun 2002
Location: Wauconda, WA
Posts: 9,784
Let's establish some common ground on our definitions. The way you stated your question makes me think your definition and ours may not be the same.

The primary grind is the grind you make that changes a blank profiled blade into a recognizable blade. This is the grind that makes the blade flat ground, or hollow ground, or saber ground (as the knife in your picture).

The secondary bevel is the grind that you use to create the cutting edge. This grind is commonly done flat as you are doing (as indicated by the sharpening jig in the picture) but can be done on a slack belt to create a convex edge as Ed described.

With those definitions in mind a blade will generally have better cutting geometry (reduced cutting resistance as Ed described) when the primary grind extends across the entire width of the blade as in a full flat grind. We may not always want the grind to be that wide and that's fine but that will come at the cost of some increased resistance.

On the secondary bevel, 25 degrees is the maximum generally used and is almost always limited to heavy chopping knives. 20 degrees (approximately) is more common on the average utility knife, hunting knife, or pocket knife. Fine edged knives like kitchen knives, fillet knives, etc might be around 15 degrees, some even finer. As Ed explained, the edge and blade design need to match the intended use of the knife.

These are just general guide lines, nothing is cast in stone....


__________________

Your question may already have been answered - try the Search button first!






Reply With Quote
  #4  
Old 09-15-2017, 10:17 AM
dtec1 dtec1 is offline
Guru
 
Join Date: Aug 2015
Location: putnam county NY ....about 45 mins north of new york city
Posts: 1,443
If I do the secondary bevel as to create a convex edge as ed was explaining I don't worry about the angle to much...yeh it gets wider for chopping knives and slimmer for slicing knives.

If I do the secondary bevel on my edge pro (similar to what you are using I assume from the pic you have a lansky sharpener or something similar.) my edge pro is a beefed up version of that it produces a flat bevel if its for a every day carry knives most knives get around 20 deg angle
Reply With Quote
  #5  
Old 09-16-2017, 04:14 PM
Rasmus Kristens Rasmus Kristens is offline
Steel Addict
 
Join Date: Jul 2014
Location: Denmark
Posts: 165
Thanks for the answers. Coud you say that thicker blades "should" have a more shallow primary bevel to minimise the resistance? Or is it still more based on the overall style abd use of the knife?

I can only do flat edges right now on a lansky jig.
Reply With Quote
  #6  
Old 09-16-2017, 04:55 PM
Ray Rogers's Avatar
Ray Rogers Ray Rogers is offline
Founding Member / Moderator
 
Join Date: Jun 2002
Location: Wauconda, WA
Posts: 9,784
Any blade thickness would need the shallowest possible primary grind in order to have the minimum resistance for that thickness. A full flat grind on a 3mm blade will have a shallower primary bevel than the same grind on a 6mm blade. That's why there's no point in being concerned with exactly what angle that might be. The size of your blade stock determines that automatically. Just choose your stock sizes by following the guidelines Ed described concerning how the blade will be used....


__________________

Your question may already have been answered - try the Search button first!






Reply With Quote
Reply

Tags
advice, angle, art, bevel, blade, blades, build, cutting, edge, flat, folding knife, grind, hunting knife, jig, knife, knives, made, materials, pocket knife, sharpening, small, steel, tool


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Secondary Bevels with 1 x 30 sander Bowman The Newbies Arena 4 12-16-2012 05:46 PM
Pic's--H.D. primary chain sandwich-damascus Fred.Rowe The Display Case 7 03-14-2007 08:19 PM
Camp knife with secondary caper Harry Mathews The Display Case 6 08-03-2006 04:52 AM
Zero secondary bevel sharpening? TikTock Fit & Finish 9 08-12-2005 04:50 PM
Aftermarket Impact on Primary Market Sales Les Robertson The Business of Knife Making 6 08-22-2001 01:52 PM


All times are GMT -5. The time now is 04:38 AM.




KNIFENETWORK.COM
Copyright © 2000
? CKK Industries, Inc. ? All Rights Reserved
Powered by ...

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
The Knife Network : All Rights Reserved