Hard chrome plating
Surface Treatment
Hard chrome plating, also referred to as industrial chrome plating, is a representative industrial plating that has a number of excellent mechanical properties such as wear resistance, corrosion resistance, and mold releasability.
Characteristics of hard chrome plating
Generally, the hardness of hard chrome plating is Hv700 or higher. Otec provides high-rigidity plating with a hardness of Hv900 or higher by adjusting the liquid composition.
Hardness of various plating films and metal materials
Plating and steel types Hardness (Hv)
Chroamor (Otec proprietary plating) 1500-1800
Chrome plating 800-1000
Nickel plating 400-500
Nickel-phosphorus plating 400-500
Nickel-phosphorus plating (with heat treatment) 800-1000
Copper plating 60
Zinc plating 40
Aluminum and aluminum alloy 20-140
Medium carbon steel (with quenching and tempering) 160-285
Austenitic stainless steel 200-260
Chromium-molybdenum steel 245-440
Comparison of the hardness of various metals produced by metallurgical processes and electrodeposition
Wear resistance
Hard chrome plating features a small coefficient of friction, which means excellent wear resistance.
Heat resistance
Heating hard chrome plating above 400℃ sharply drops its hardness. At Otec, the baking process for removing hydrogen after plating is performed under strict temperature control by using a dedicated furnace.
Change in the hardness of chrome plating during heating (heating time: 3 hours)
Corrosion resistance
Hard chrome plating is stable against chemicals other than chlorides.
Oil retainability
Microcracks on the surfaces of hard chrome plating provide excellent oil retainability. To further improve oil retainability, we can also support porous chrome plating that provides wider cracks.
Plating characteristics

The treatment temperature of hard chrome plating is as low as approximately 50°C, which means that there is almost no thermal influence on materials.。

The surface roughness of the workpiece to be plated can be freely adjusted. (Ultra-mirror finish (0.05S or lower), satin finish (matte finish), semimatte finish, mirror pocket finish, etc.)

Hard chrome plating ensures dimensional accuracy and allows replating and partial plating (overlaying).

Using nickel plating as an undercoating improves the corrosion resistance of hard chrome plating.

Materials that can be plated
Hard chrome plating can be applied to a wide range of metal materials including steel, stainless steel, aluminum, copper, copper alloys, nickel, and titanium.
Uses of hard chrome plating
Various rolls, various molds, cylinders, pistons, piston rods, various shafts, coater bars, etc.

Chrome-plated roll for manufacturing optical films

Chrome plating on coater bar

Facilities related to hard chrome plating
Plating bath
Total amount of liquid
11 baths
Approx. 120,000 liters
Rectifier 23 units (total quantity of electricity: approx. 83,000 A)
Crane 10-ton crane etc.
Cylindrical buffing machine 7 units (max. 850 mm diameter × 6,000 mm long)
Internal diameter buffing machine 2 units
Liquid honing equipment 1 unit
Large baking furnace 2 units (internal dimensions: 1,600 mm W × 5,300 mm L × 1,400 mm H)
Note: We also accept a job request for only heat treatment.