Sharpening Handbook

Adze

The Adze is a tool which is swung about a pivot point when used, and has two key angles, α and β.

Edge Angle

the effective angle at the cutting edge. The inside and outside edges will probably be cleaned up and polished; however this is the effective angle between those edges.

When resharpening, try to to not change the β angle

Only resharpen the tool on the inside edge (the upper part in the picture to the left), and
Hone/strop both the inside and outside edges.

Edge Angle

the angle between the handle and the cutting edge. As the adze is a tool which is swung about some pivot point, this angle has a great impact on the usability of the tool.

If β is too large, the area behind the cutting edge will impact the wood before the cutting edge.
If β is too small, then the cutting edge will dig into the wood.

The angle needed for β is out of scope of the Sharpening Handbook, however, there are articles below which address how this can be determined, and how to set it.

It requires a genuine fight to produce one well-designed object of relatively permanent value.

George Nakashima

General Guidelines
Tool Usage	α		Notes
Tool Usage	Range	Recom.	Notes
Softer woods or Finishing cuts	25° - 30°	25°	I've seen recommendations for α as low as 20° however this could be too shallow unless the user is working on very soft woods.
Hard woods or Roughing out cuts	25° - 35°	30°	Use a higher α when working on dry hard woods.

Notes & Comments

Resharpen the Inside Edge

When resharpening, it is best to only work on the inside part of the bevel. Modifications to the outside part of the bevel (the back bevel) could adjust the β angle, also known as the “hang” of the adze.

Having a bevel on the outside of the tool allows it to be better used for shallow scalloping work. The article by Dave Fisher in “Fine Woodworking” magazine shows this well.

This back bevel should be around 2°, and certainly not exceed 5°.
It is usually a convex edge (vs. flat or concave). Once this is set, it is best to not modify the outside edge.

Lipped Adze

Sharpen a Lipped Adz

To sharpen a lipped adze (also known as a shipwright's adze, and used for cutting across the grain), see the instructions in The Complete Guide to Sharpening by Leonard Lee. The recommended α angles follow those noted above; however the directions are a bit difficult to describe.

More Information

Books & Papers

The Complete Guide to Sharpening by Leonard Lee

Published Articles

Nic Westerman of Hewn & Hone wrote a great series about the adze which was published in “Wood Carving” magazine. It was published in 3 parts. (Here is a link to Nic's Instagram page)

Part 1 - Issue 190, page 60. This addresses the β angle and why it matters.
Part 2 - Issue 191, page 70. This also addresses the β angle, and how to adjust it.
Part 3 - Issue 192, page 60. This addresses the α angle and a few other points.

Dave Fisher wrote an article for Fine Woodworking where he overviews how to tune-up an adze. The web link excerpted here was part of the article where he discussed what to look for when purchasing an Adze. “Fine Woodworking” magazine, issue 285, Nov/Dec 2020, pg. 24
Note: Dave was not merely resharpening the tool; rather he had to do some fairly significant reshaping to the tool's cutting edge. If you do such do such modifications to a tool, be sure to manage the heat so that you don't lose the temper in the metal.