Different industries have vastly different requirements for coating hardness based on their own production characteristics, usage environments, and product functional requirements. The following are some typical industry situations:
Mechanical manufacturing industry
Protection requirements for components: In mechanical manufacturing, many components need to work in environments that can withstand high friction, impact, and alternating loads. For example, components such as crankshafts and pistons in engines require coatings with high hardness to resist wear. Generally, coatings with a hardness of around 50-65 Rockwell hardness (HRC) are required to reduce wear and extend service life under long-term high-speed operation and frequent friction conditions. For some ordinary mechanical transmission components that can withstand small loads, the hardness requirement is relatively low. A Rockwell hardness (HRC) of 30-50 is sufficient for normal use, with the focus on ensuring a certain level of wear resistance while considering factors such as cost.
Application scenarios of cutting tools: Metal cutting tools have strict requirements for coating hardness, such as hard alloy tool coatings, whose hardness usually needs to reach Vickers hardness (HV) 2000-3500 or above, so that when cutting metal materials (such as steel, titanium alloys, etc.), the workpiece can be easily cut in, the blade can be kept sharp, tool wear can be reduced, cutting efficiency and machining accuracy can be improved.


Aerospace industry
Engine component considerations: High temperature components inside aircraft engines, such as turbine blades, not only need to withstand high temperature environments (usually above 1000 ℃), but also require high hardness coatings to resist high-temperature gas erosion, particle erosion, etc. The coating hardness needs to reach a high level, for example, the Vickers hardness (HV) of some advanced coatings can reach around 1500-2500, ensuring that the blades maintain structural integrity and guarantee engine performance and safety under extremely harsh and high-speed operating conditions.
External surface protection of aircraft: The coating on the external surface of the aircraft should be able to resist airflow erosion, sand and dust impact during flight, and meet certain weight reduction requirements. Its hardness requirements are relatively moderate, usually with a Rockwell hardness (HRC) between 40-60. While ensuring sufficient wear and impact resistance, it does not excessively increase weight and should be coordinated with other functions such as corrosion prevention and stealth.
Electronic and electrical industry
Circuit board protection: The coating on the circuit board is mainly used to prevent damage to the circuit and components caused by dust, water vapor, chemical corrosion, etc. The hardness requirement is relatively low, generally around 50-80 Shore hardness (HA). The key is to have good insulation, corrosion resistance, and flexibility, which can fit the complex shape of the circuit board and provide stable protection, rather than focusing on high hardness to resist external wear and tear.
Electronic device casing: The coating of electronic device casing is mainly considered from the perspectives of aesthetics, wear resistance, and fingerprint resistance, and the hardness requirements vary depending on the positioning of different devices. For example, the shell coating of ordinary consumer electronics products, with a Shore hardness (HA) of 70-90, can meet the slight friction and scratching conditions in daily use; For some industrial grade electronic device casings, higher hardness may be required, with a Shore hardness (HA) of 90-110, to cope with relatively harsh usage environments.
Automotive manufacturing industry
Vehicle body coating: The main purpose of coating the surface of the vehicle body is for aesthetics, corrosion resistance, and a certain degree of scratch resistance. Usually, its pencil hardness is between 2H-4H, which can maintain the integrity of the paint surface in daily car washing, slight scratching, and other situations, providing good protection for the appearance of the car, while meeting the aesthetic and texture requirements of the car appearance.
Internal parts of the engine: Some parts inside the automobile engine, such as valves, lifters, etc., are similar to the mechanical manufacturing industry and require high mechanical stress and friction. The coating hardness requirement is high, with a Rockwell hardness (HRC) of about 55-70, to ensure that the engine reduces wear and maintains good working condition during repeated starting and long-term operation.
Medical device industry
Implanted devices: Medical devices implanted into the human body, such as artificial joints, require a coating hardness that is within an appropriate range. It should be able to resist the corrosion of body fluids, have good biocompatibility with surrounding tissues, and have a certain hardness to withstand the friction and pressure generated by daily human activities. Typically, the Vickers hardness (HV) is around 500-1000 to avoid damage to surrounding tissues caused by excessive hardness and to prevent rapid wear and tear caused by excessive softness, which may affect the service life.
Surgical instruments: Surgical instruments require coatings with good cleanliness, corrosion resistance, and a certain degree of hardness to resist wear and tear during disinfection and damage caused by collisions between instruments. The hardness is generally between 30-50 Rockwell hardness (HRC), ensuring that the instruments maintain good performance and appearance under repeated use and frequent disinfection.
Overall, there are significant differences in the requirements for coating hardness among different industries, which are determined and evaluated based on their core production and operational needs as well as the specific environment in which the product is located.

Room termperature curing polysilazane, pls check IOTA 9150, IOTA 9150K. 
High termperature curing polysilazane, pls check IOTA 9108, IOTA 9118.