Film strength, hardness, adhesion are important physical properties of the film, it directly affects the wear resistance, wear-resistant grain, scratch resistance; The impact resistance and the retention of the coating film and the difficulty of cleaning, so the strength and hardness of the coating film are the necessary indicators to evaluate the performance of the coating. The use of this instrument can be convenient and comprehensive assessment of the film strength, hardness, adhesion and other physical characteristics, so the purpose of this instrument is to characterize the strength, hardness and adhesion of the coating through the penetration resistance of the paint film template coating when it is scratched by the needle.