Known to many as 'factory customs', Rockstead knives are some of the highest quality factory made knives on the market. The knives are made by a highly skilled eight-man team, who operate proprietary machines.
At The Old Man Knives & Tools in Amsterdam, we have one of the largest physical collections of Rockstead knives in Europe. What makes these knives so unique?
1. The edge geometry.
2. The edge finish.
3. The steel.
1. Edge geometry
Rockstead applies a so-called "Honzukuri" blade shape to some of their models. This basically means the blade is ground convex on both sides, without a micro bevel. This makes for a very strong edge since this is the most stable edge geometry in existence . Their main inspiration for this shape was the Japanese sword.
Shinogizukuri is another shape Rockstead uses. It is the result of Rocksteads constant journey towards optimal cutting performance. ‘Shinogi’ is a Japanese word describing a line where two surfaces meet. This blade shape features two surfaces. The amazing thing about this is that the angle of the cutting edge starts at 30 degrees from the handle and gradually moves to 24 degrees at the tip. This is done in one continuous flow.
2. Edge finish
The finish on a Rockstead knife is truly astounding. The knives have a mirror finish which is completely smooth and reflective. A lot of work and dedication goes into this process. Not only is it beautiful, it actually makes the knife retain it’s edge longer. Rockstead believes that the smoother the surface is, the longer the knife stays sharp. The reason for this, is that they believe nicks in the steel are most commonly caused by the micro serrations and/or imperfections in the surface of the edge
Rockstead uses two high quality exotic super steels in their knives: ZDP-189 and YXR7. Both are currently produced by Hitachi Metals Ltd. in Japan
- ZDP-189 is an ultrafine powder-metallurgic stainless steel containing a stunningly high percentage of 3% carbon and 20% chromium. Rockstead is able to get their ZDP-189 to an incredible hardness of around 67HRC. The characteristics of ZDP-189 which include an ultrafine microstructure causing an amazing edge retention, make for a great knife steel. Rockstead, however, turns their ZDP-189 into a piece of art, using their craftsmanship and proprietary machines to produce an edge finish unlike anything else in the knife world.
- YXR7 is an ingot high-speed tool steel which makes for very tough knives. Rockstead gets these knives to a whopping 65HRC and manages to keep the edge retention on par. Much like ZDP-189, this steel contains a very high percentage of carbon and because of a different balance in composition this steel is tougher, but it has a lower tolerance to rust. Rockstead fights this battle head on, by applying an ultrahard DLC (diamond like carbon) coating to the YXR7 blades. Because the very apex of the cutting edge is not coated, it is advised to keep the edge dry and clean.
Edge durability is, amongst other factors, influenced by the hardness of the blade steel. This hardness is tested with a special device that presses a real diamond tip into the test material. This way, resistance against plastic deformation is tested. The result of this test will be a number in Rockwell hardness. As opposed to other blade manufacturers, Rockstead Knives tests their blades individual for hardness to a tenth of a Rockwell. The result of each individual knife testing is displayed on the certificate accompanying the knife.
The DLC Coating is applied to the YXR7 blades specifically, to protect the steel from rust. This is done by bonding Carbon to the blade in a vacuum oven at a heat of 500˚C. The result is a 3 micron thick layer with an approximate hardness of diamond (Hv1800 on the Vickers scale). It also gives the blade a beautiful dark sheen.
The Prism coating is applied to the Titanium handles on some Rockstead models. Much like the process of a “regular” DLC coating, the material is placed in an oven and heated to 400˚C. A Vickers hardness of approximately Hv3000 is reached. During this process, the specialists at Rockstead add a special coating, which leaves the Titanium with a strong and beautiful multi-coloured coating.
The Old Man Knives and Tools - Amsterdam
Here at The Old Man Amsterdam, we have been working together with Rockstead for many years and are proud to say we have one of the largest physical collections of Rockstead knives in Europe. The professional demeanour, integrity and total devotion to the world of knives has brought us together to bring the quality of Rockstead all the way from Osaka, Japan to Amsterdam, The Netherlands.
Come by our store to see our unique store and the unique Rockstead collection for yourself.