When buying a new knife, the type of knife blade finish can offer various advantages, especially when in the field. Here is a quick guide to understanding what each blade finish offers and how it can add strength and durability or improve the look of a knife.
Hand Satin Finish: A hand satin finish involves sanding the blade in one direction with increasing degrees of a fine abrasive (generally sandpaper). A satin finish shows the blade’s bevels, showcasing the knife’s lines while reducing its reflective glare. Hand satin finish is generally done on upscale, high-end, collector-grade knives. The finer the abrasive and the more even the lines, the cleaner the satin finish blade looks. Satin finishes can also be used on the handle or fittings to enhance the knife’s look. A lovely hand-satin finish takes time and can increase the cost of the knife.
Brushed Finish: A brushed finish using an abrasive wheel that creates a satin-like finish pattern. Overall, it provides an attractive work finish without the cost of a hand-satin finish. It’s possible to combine a brushed finish with a hand-satin finish.
Mirror-Polished Finish: A mirror-polished finish is done by hand, polishing the metal into a highly reflective surface. While it provides a great look and offers better corrosion resistance due to the smoothness of the blade, this finish type involves much polishing to maintain its look, and its reflective quality would be telling in tactical fieldwork. The amount of skill used to create this finish often results in an expensive blade. A mirror finish is quickly scratched and is primarily a presentation finish.
Blasted Finish: Using abrasive, glass, or ceramic beads, the finish is made by blasting the materials at high pressure against the metal, resulting in an even grey finish. A blasted finish reduces reflection and glare due to its even matte surface. Creating a blasted finish is a base-level or user-level finish on a knife blade. The blasting creates an increased surface area, and micro-abrasions make the steel more prone to rust and corrosion. Even from stainless steel, a blasted blade can rust overnight if left in a humid environment.
Coated Finish: Usually black, flat dark earth, or grey, a coated finish reduces the reflection and glare while reducing wear and corrosion. However, ALL coatings can be scratched off after continuous heavy use, and the blade must be re-coated. Generally, the more complex the finish, the more resistant it is to wear and the more expensive to add to a knife. High-quality finishes are bonded electrically, chemically, or thermally to the surface instead of simple drying paint-like coatings. High-end coatings like DLC (Diamond-Like Carbon) require that the blade goes to a specialty coating facility for PVD (Physical Vapor Deposition) application in a vacuum environment.
Interestingly, most blades receive a blasted finish before being coated to have maximum adhesion surface area. Coatings can prolong the life of a blade (especially with carbon steel) by preventing corrosion or rust. Quality coatings add cost to a knife but provide more corrosion resistance, less reflection, and require less maintenance.
Stonewashed finish: A stonewashed finish means tumbling the blade in an abrasive material. This finish quickly hides scratches while providing a less reflective nature than a brushed or satin-finished blade. There is a wide variety of stonewashed finishes based on the abrasive shape, tumbling motion, and the type of finish the blade has before it enters the tumbler. An “acid stonewashed” or “black stonewash” finish is a blade with an acid treatment that darkens the blade before it undergoes stone washing. The acid oxidation enhances a blade’s rust resistance by placing a stable oxide barrier between the steel and the environment. A very positive benefit of stonewashed blades/handles is that they are low maintenance and preserve their original look over time; the stonewashed finish hides the scratches that can occur with use over time.
Overall, each finish has its advantages and critiques. Depending on what you will be using your knife for, its finish can maintain its look or durability. Knife blade finishes affect the overall cost of a knife and should reflect the knife’s intended purpose. A blade finish is an aesthetic and practical choice when evaluating knives.