



The Atoma Tsuboman Diamond Sharpening Plate #400 is a replacement abrasive surface designed for use with an Atoma aluminum base. The #400 grit offers an excellent balance between material removal and control, making it suitable for edge restoration, preliminary sharpening, and waterstone flattening.
Its working surface is coated with evenly distributed diamond abrasive particles that provide fast cutting performance and long-term consistency. Unlike conventional waterstones, the plate maintains its flatness throughout use and does not suffer from dishing or deformation, ensuring reliable sharpening results.
The #400 grit is particularly useful for restoring dull edges, removing minor damage, and preparing blades for finer sharpening stages. It is also widely used for maintaining the flatness of waterstones, allowing users to restore sharpening stones quickly and accurately.
The diamond abrasive works efficiently on traditional carbon steels and stainless steels, as well as highly wear-resistant powder metallurgy steels. It performs especially well on demanding steels such as ZDP-189, HAP-40, and SG2/R2, delivering excellent performance even on very hard materials.
As a replaceable abrasive component, the plate offers a practical and economical way to extend the life of an Atoma sharpening system. Its slim profile and lightweight construction make it easy to store and handle while maintaining the durability and precision associated with Tsuboman products.
Specifications:
- Product Type: replacement plate for aluminum base
- Grit: #400
- Overall dimensions: 210 x 75 x 1 mm
- Abrasive: diamond grit
- Replaceable abrasive part
- Weight: 130 grams
- Used for: knives, razors, chisels, scissors
- Origin (Made in): Japan
Advantages of Atoma diamond sharpening stones:
- Quickly removes material during repair or blade geometry changes
- Fast grinding and flattening
- Can be used to sharpen very hard powder steels (ZDP-189, HAP-40, R2)
- Retains its shape and does not wear out or dent during use
- Lower grit sizes (#140 and #400) are ideal for flattening sharpening stones

