Sharpening Handbook

Sharpening Handbook - Marking Knives

Because sharp enough
... usually is not.

Guidelines shown below are for Included Angles (⍺).

Notes about Secondary Bevels are at the bottom of this page.

If you want to get truly sharp, Dr. Vadim Kraichuk with KnifeGrinders has a really good method and has adapted the Tormek system to these wheels. The KnifeGrinder method is one that is proven, and has great tools to assist with making it easy.

CB's USB Projection Calculator is recommended for calculating setup for Tormek knife jigs. (The simpler Projection Calculator is also still available.)

General Guidelines
Marking Knife	25º	2º	Included angle is the same as the bevel angle as only one side is beveled. The back is flat, and it is fundamentally sharpened as if it were a woodworking chisel. Generally, there is a 120º angle on the leading V. Some chose to round off the pointed tip. The Tormek SVM-45 works well for these.

General Guidelines

Type

Micro
bevel

Notes

Marking Knife

25º

2º

Included angle is the same as the bevel angle as only one side is beveled. The back is flat, and it is fundamentally sharpened as if it were a woodworking chisel.

Generally, there is a 120º angle on the leading V. Some chose to round off the pointed tip.

The Tormek SVM-45 works well for these.

Notes & Comments

Information regarding Grindstones

Secondary Bevel Notes :
- Some recommend a secondary bevel angle of +5º, even up to +10º. That is a decision the user should take over time.
- Dr. Vadim Kraichuk's research showed that +0.4º is recommend for the best sharpeness (see also, "Sharpeners Report", February 2018).
- Once this becomes too time consuming (i.e., the secondary bevel becomes too large), then you will have to regrind the primary bevel.
Online Calculators which can be used for sharpening knives.

Research Articles, Other Information, and some Final Thoughts.

It is a common, but quite bad, practice of drawing the newly sharpened knife edge through a piece of wood or some other media to “rip off” the remnants of the burr. When this is done, the ripped off metal builds up on the front of the slice, and you then drag the rest of the edge through this crud. This crud, together with breaking off of ledges of material along the edge, will roughen the edge and worsen sharpness.
The following scanning electron microscope (SEM) images show the burr on a knife in the 1st image, that was then “ripped off” by cutting cross-grain into a piece of redwood in the 2nd image – loss of the sharp edge is obvious.

Click on either image for bigger size.
Images courtesy Todd Simpson via Dr. Vadim Kraichuk of KnifeGrinders
Key take-away from these photos : don't skip the honing step.

Jan Svancara posted a design for using a knife sharpening platform in 2015 on the Tormek Forum. This is certainly worth reading, and there are also pictures of this in the jigs section.

Good videos showing the use of the Tormek Knife Jigs : SVM-45, SVM-100 (no longer sold), SVM-140, and SVM-00:

Jeff Farris - Knife Sharpening with Tormek
Steve Bottorff - Using Tormek Knife Jigs
Tormek Knife Jig SVM-45
Tormek Long Knife Jig SVM-140
Tormek Small Knife Holder SVM-00
Tormek AngleMaster WM-200
Herman Trivilino showing the use of a platform jig
Knife Grinders showing sharpening of knives with convex curves
Knife Grinders showing sharpening of knives with concave curves
Knife Grinders showing how to mounting the pin pivot collar on your knife jig Pin Pivot Jig

Tormek is a copyrighted logo of Tormek AB. Its presentation on this site is used to help the user quickly understand when specific Tormek tools, jigs, or setting are being used. For specific information regarding Tormek AB, or its products, please refer to the www.Tormek.com.

About this site Remember : The goal of sharpening is to produce sharp tools, and these tools can injure you if mishandled. Safety measures should be followed to protect yourself and those in your shop. Be sure to read and follow all instructions from the manufacturer, and and utilize proper safety equipment. Never consume alcohol or anything that could impair your judgement before sharpening tools, or using sharp tools. Comments can be sent via eMail to me at SharpeningHandbook@Gmail.com.