When you thumb through the latest tool or parts catalog you received in the mail, you’ll notice tools with varying surface finishes. Each type of surface finish has positives and negatives, depending on your needs. Two of the most common surface offerings are chrome plating and black oxide. A common question that we are asked is what to choose when deciding between chrome plating versus black oxide tool finishes. In this article, we discuss the advantages of both chrome plating and black oxide as well as what types of mechanics each surface treatment would benefit the most.
Chrome Plated Tools
Chrome plating has been a process used for decades to give tools a decorative and durable surface. Chrome plating is a process of electroplating a thin layer of chromium onto a metal surface. The complete chrome plating process typically involves a degreasing process, a secondary manual cleaning process to remove any additional traces of dirt or impurities, a pre-treatment process depending on the metal to be coated, placement into a vat of chrome plating solution, and then application of electrical current to bond the chromium to the metal surface. Once the desired finish thickness is achieved, the tool is typically removed and rinsed in a water bath. The plating process offers users great corrosion protection, easy cleaning, and is applied to tools ranging from ratchets to sockets to combination wrenches. Thicker chrome plating has an increased surface hardness that will offer superior durability over the life of the tool use. A final benefit is that chrome plated tools are reflective, so if you miss your magnetic tray and drop a socket into your engine bay, you can easily spot it with a flashlight since it will catch your eye when the light hits it. For this reason, most off the shelf mechanic’s tool sets contain chrome plated tools.
While chrome plating offers a shiny and durable surface, the many steps involved add additional cost to the manufacturing process. That cost is often transferred to the end user, and that can make chrome plated tools less affordable than other options. Also worth mentioning is that chrome plated tooling tends to be slippery when wet as the surface tends to be very smooth. If you plan to use a chrome plated tool in a location where it could be exposed to fluids (such as changing a water pump or radiator), the tools can become a little harder to hold so you’ll have to be mindful.
Black Oxide Tools
As with chromium plating, the application process for a black oxide finish is similar and typically includes a cleaning process, immersion in a solution, and then application of the final finish on the end product. Black oxide has different variations in the process depending on the base material, but for most tooling a cold temperature black oxide process is used. This process is typically done at room temperature which results in lower manufacturing costs. The coatings are often impregnated with oil, wax, or lacquer to further improve the corrosion resistance and durability. Black oxide finishes are less common than chrome finishes, but they’re most often found on impact sockets, impact extensions, and other impact tools. This is because the finish tends to be a little bit more ductile and thus more resistant to chipping than chrome, which is brittle and will chip if used with an impact wrench. For this reason, many consider black oxide to be more durable.
While manufacturing costs for a black oxide finish can be lower than comparable chrome plating processes, one of the disadvantages is the visibility. Black tools are harder to find in a dimly lit garage or in the back of a deep tool chest drawer since they don’t reflect light. It is for this same reason that the barrels of firearms are often finished in black oxide (to make them harder to spot). Black oxide tools tend to have more texture and can thus offer a slightly better grip in dry conditions, and tend not to get quite as slippery when wet.
Overall, when it comes down to choosing between chrome plating versus black oxide finishes, the positives and negatives of each tend to be pretty clear. Ultimately, you are weighing how visible your tools are, how durable your tools are, and how much they cost. Furthermore, availability comes into play as you won’t find impact tools with chrome finishes, so you are more or less forced to use black oxide coated tools if you intend to use air tools. If you aren’t sure which to get, we typically recommend black oxide as a first choice since they tend to be more durable and slightly lower cost. Happy wrenching!