Manufacturers are offering more and more choices with their multi tool models. Now after you decide which multi tool to purchase, the other big decision you have to make is do you get it with black oxide coating or regular stainless steel?
Black oxide coating provides a matte finish that is less reflective and provides a tactical look. Because multi tools are already made from stainless steel, the black oxide does not provide other benefits. New black oxide multi tools are stiff with gritty actions because the coating affects tolerances and the powder gets into the pivot joint.
Our troops and members of law enforcement have a need for equipment that can be used without drawing attention and black oxide multi tools are the obvious choice. After doing the research, we think that most regular users are better served getting a standard stainless steel finish on their multi tool.
What is the Black Coating on Multi Tools?
Black multi tools from Leatherman, Gerber, SOG and Victorinox are created by taking the stainless steel tool and applying a black oxide coating. Black oxide is not the same as black anodization that can be applied to aluminum or titanium parts. Some knives and other tools from the same brands use black anodization, but they do not use it on their multi tools.
The black oxide is not painted or plated on, instead it is formed by a chemical conversion. The multi tool is placed into a chemical solution that contains oxidizing salts and these salts react with surface of the metal to form black iron oxide (also known as magnetite, Fe3O4).
Is Black Oxide Stainless Steel Better than Uncoated Stainless Steel?
This topic has a lot of conflicting opinions on the internet due to the fact that black oxide coating over carbon steel does provide significant benefits.
Corrosion Protection – some black oxide treatments can provide significant corrosion resistance, up to the equivalent of 144 hrs of salt spray exposureCleveland Black Oxide
Dimensional Stability – critical dimensions are less affected by black oxide than by painting or plating processes
Anti-galling – where mating parts make contact the outer layer is sacrificed while forming the work-hardened surface. Black oxide has a hardness of 5.5 on the Mohs scale of mineral hardness
Pre-Treatment – Paint and other finishes adhere better to black oxide than they do to the metal itself. There is less chipping and flaking and the finish lasts longer.
Decorative Finish – Black oxide looks good just by itself. Harder metals tend to have a glossier appearance while softer metals will tend to have a matte finish.
Reduced Light Glare – Black oxide is less reflective than the underlying metal for less glare and less eye fatigue when used under bright lights.
Cost Competitive – Few other coatings for ferrous metals offer the same performance benefits for comparable cost.
Does Black Oxide Stainless Steel Rust?
Applying black oxide to standard metals improves their performance in many ways. However, multi tools are already constructed of stainless steel and do not get any meaningful corrosion benefits from black oxide coating. Black oxide coated stainless steel will rust just the same as uncoated stainless steel.
Benefits of Black Oxide Coating for Multi Tools
Beyond the matte appearance, black oxide multi tools have one other advantage over their stainless steel brothers. Stainless steel is smooth and can be slippery, especially polished stainless steel like on Victorinox SwissTools. Black oxide coating gives slightly better grip. The black oxide is not rough, but provides better tactile feedback than regular stainless.
Disadvantages of Black Oxide Stainless Steel
While researching black oxide coating we came across a number of complications with black oxide multi tools. Some were obvious and others surprised us.
Does Black Oxide Wear Off?
New black oxide tools are known for leaving black smudges on your hands for weeks but this is not the coating wearing off. The coating process leaves a residual powder that they don’t clean off at the factory. For most cases all you need to do is give it a good wipedown with a microfiber cloth, handle severe cases with our standard cleaning procedure.
Because the black oxide coating is only about 50-100 microns thick it will show signs of wear over time. With use the surface will discolor and scratches will show the underlying stainless steel. For every owner that thinks these battle scars give their tools more character there is another that thinks they look tired and used – it really is a personal preference.
Harsh chemicals will attack black oxide, especially strong acids. Use caution with your black oxide multi tools around cleaners and chemical strippers.
When you get a scratch on regular stainless steel it is less noticeable. If it does bother you it can remove it with buffing compound.
Stiff Tools and Gritty Pivot Joints
Some Leatherman tools are notoriously stiff from the factory and the black oxide versions have an even worse reputation in the forums. If you have a new Leatherman Wave+, Surge, or Super Tool 300 be sure to read How to Break in a New Leatherman. When the tolerances are so tight to begin with even the few millionths of an inch make a difference.
The same powder from the coating process that comes off on your hands also gets everywhere inside the tool, including the pivots for the pliers, knife blades, and other tools. Grit in the pivots make them rough and even more difficult to open.
Black Oxide Tools are Less Visible
Less reflective and less visible are good characteristics for our servicemen and women, but they work against us in everyday life. It makes your multi tool harder to find when you drop it outside in the grass. The tool is less obvious when you set it down inside an engine bay or at the work site.
Alternatives to Black Oxide Coating
Besides black oxide, the only other option currently available is from Leatherman with the Skeletool CX. Leatherman uses a DLC coating on the stainless steel handle components. DLC stands for Diamond-Like Coating and is a carbon-based coating that increases resistance to scratches and corrosion.
DLC (diamond like coating) is a carbon-based coating that displays some of the unique properties of natural diamond. It is applied for scratch and corrosion resistance. The coating is very hard and smooth as well as anti-reflective. The 154CM knife blade is not coated with DLC so the blade is still silver colored, but you do get the corrosion benefit of the better steel.