Sharpening Handbook

Sharpening Handbook - Japanese Wood Chisel

Because sharp enough
... usually is not.

Japanese chisels are keenly defined by the laminated blade. The cutting edge (bottom) is a high carbon steel for maximum sharpening capabilities, and the upper edge is a low carbon steel which facilitates shock absorbtion and makes sharpening easier.

The article, "Choosing and Using Japanese Chisels" in Fine Woodworking magazine, May/June 2013, is highly recommended.

Guidelines shown below are for Primary Bevel Angles & Secondary bevel angles (also known as micro bevel angles). Notes are also available on a different web page for Micro / Secondary Bevels.

Primary & Secondary Bevels both ground on a wheel.

Primary Bevel ground on a wheel
Secondary Bevels ground on a flat stone

General Guidelines
End Profile / Type	Usage	α		Notes
End Profile / Type	Usage	Primary Bevel	Secondary (Micro) Bevel	Notes
Kaku Uchi	Soft Woods Hard Woods	35º 40º		An old style with only slightly raked sides. This blade profile delivers maximum power for chopping but is less versatile when paring. Mortise chisels often have this profile.
Kinari	Narrow (< 8 mm) Standard (8 - 25 mm) Wide (> 25 mm)	35º 30º 25º	2º	This has longer bevels than the mentori, and the more delicate profile is excellent for paring dovetails but still retains enough mass for effective chopping.
Mentori	Narrow (< 8 mm) Standard (8 - 25 mm) Wide (> 25 mm)	35º 30º 25º	2º	This is the most common blade profile. It combines heft for chopping and striking with side bevels for paring access.
Shinogi	Soft Woods Hard Woods	25º 30º	2º	This has a low, wide-beveled blade profile which affords excellent access when paring in tight spaces. It is an un-hooped chisel, not meant for striking. Crank-neck chisels often have this profile.

Notes & Comments

Information regarding Grindstones

Secondary Bevel Notes :
- Some recommend there be no secondary bevel angle.
- If the user chooses to have a secondary bevel, 2º is recommend as this allows for repeated resharpening by touching up the secondary bevel only. Once this becomes too time consuming (i.e., the secondary bevel becomes too large), then you will have to regrind the primary bevel.
Some also advocate only using flat stones, including Toshio Odate, author of Japanese Woodworking Tools : Their Tradition, Spirit, and Use (1998), and John Reed Fox.

Be sure to coat all newly sharpened surfaces with camelia oil to minimize chances for rust.

Hollow(s) in the Back Face :
- Hollow(s) in the back face should be >⅛ inch (0.1250 in / 3 mm) from the cutting edge. If less, tap it out as necessary. (There is a great video from Andrew Hunter on the Fine Woodworking site.)

Tormek SE-76 Square Edge Jig
Using the SE-77 Jig to Camber a Plane Blade on the Tormek Sharpener
Tormek SVH-60 Straight Edge Jig (this jig is no longer sold, but is quite useful for short tools)
Tormek AngleMaster WM-200

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.