Knife review : Hiromoto Gyuto 240 mm

Knives : Richmond Artifex Gyuto Hiromoto Gyuto Yamashin Gyuto Henckel's Twinmaster Chef This review consists of : introduction and specifications stock evaluations extended use, edge retention sharpening corrosion resistance grip steel overview comments and references

Introduction and Specifications

Seller Webpage : Hiromoto Gyuto :

Hiromoto has been producing professional quality knives for decades in Seki City, Japan. The knives that we carry are the Aogami Super line and are forged from carbon steel, an ultimate Hagane refined from Yasugi sand-irons. These knives are made of high Carbon steel (1.40 - 1.50) with Chromium (0.30 - 0.50) and Tungsten (2.00 - 2.50) added for edge retention and durability. The hardness of the steel measures Rockwell 60-62. The blades are clad with 405 stainless steel to protect from rusting except the cutting edge. The result is an easy to sharpen knife that is durable and perfectly balanced and can hold a razor sharp edge. We highly recommend these knives.

• weight: 8.2oz
• blade length: 238mm
• spine thickness: 2.39mm
• $164.95, April 2013

Some comments from the seller on the steel :

Aogami Super

• Carbon: 1.40 - 1.50%
• Tungsten: 2.00 - 2.50%
• Vanadium: .30 - .50%
• Chromium: .30 - .50%
• Molybdenum: .30 - .50%
• Manganese: .20 - .30%
• Phosphorus: .025%
• Sulfur: .004%
• Silicon: .10 - .20%

This is one of the most popular high carbon steel alloys amongst Japanese knife makers. It is known for the very high edge retention and fine edge it is capable of. Wear resistance is medium so it is very easy to sharpen. It is very reactive so wiping down and drying should be done after every use. Moritaka and Takeda are two of the most well-known makers using this steel.

Initial impressions :

• chamfered spine and heel
• nice taper on the front of the handle to the blade
• handle is very well rounded
• bolster edges are squarish
• tang is slightly crowned and rough
• balance is a little in front of the bolster
• very light convex grind

A bit of geometry :

• stock is 0.095"
• 4" distal taper, 1/4" back from the tip the blade is only 0.025" thick
• edge is 0.005" thick

Stock cutting

The initial sharpness was measured at :

• Push cut Espirit baisting thread with 70 (5) grams
• Slice Berga spinning thread under 40 grams of tension with 0.75 (25) cm

On 3/8" hemp :

• push : 19 (1) lbs
• slice : 9.5 (5) lbs

In short, very high as-boxed sharpness and cutting ability.

Food

Grip

Ergonomics :

Security :

Durability :

Miscellaneous :

Sharpening

Edge Retention

As the only knife used in the kitchen, it was brought into rotation on Jan. 27 / 2013 and lasted XX weeks before it had to be sharpened.

As a very basic check on edge retention, through 1000 slices through pine :

Cardboard trial :

Corrosion Resistance

Steel

Overview

Overview :

Comments and references

Comments can be emailed to Please Use the Forum or by posting to the following thread :

• Intro

and/or the YouTube Playlist for Kitchen Knives.

Most of the pictures in the above are in the PhotoBucket album.