Successful Use of Shin-Etsu G-330 High-Tack Silicone Grease in Damping Mechanisms of Precision Optical Equipment

A leading Japanese manufacturer of high-end cameras and lenses faced a challenge during the development of a new electric zoom lens: finding a lubricant that could deliver consistent damping performance across a wide temperature range. The focus and zoom rings in the lens employ rotary sliding mechanisms that require smooth, uniform resistance to ensure premium user feel. However, conventional mineral-oil-based greases exhibited significant torque variation—becoming too stiff at low temperatures (e.g., –20°C) and too fluid at elevated temperatures (e.g., +80°C)—compromising operational consistency.

The engineering team selected Shin-Etsu G-330, a high-tack silicone grease from Shin-Etsu Chemical Co., Ltd. made it an ideal match:

• High tackiness: Forms a stable, adherent film on sliding/rotating parts, delivering superior damping;
• Wide temperature stability: Usable from –30°C to +150°C, with minimal torque variation observed between –20°C and +80°C;
• Medium shear resistance: Standardized torque testing (50 manual rotations followed by 1 min at 10 rpm) yielded a consistent value of 23 × 10⁻⁴ N·m, ensuring uniform tactile feedback;
• Low volatility and oil separation: Oil separation of only 0.01% and volatile content of 0.05% after 24 hours at 105°C, minimizing risk of drying out or migration over time.

G-330 was applied to metal-plastic rotary bearings and sliding rails inside the lens assembly. After accelerated aging tests (85°C / 85% RH for 500 hours) and real-world user trials, the damping feel remained consistent across thermal cycles and high-humidity conditions—no “stick-slip” or loss of resistance was observed. Additionally, its white appearance and low low-molecular-weight siloxane content (≤100 ppm) met stringent cleanliness and material compatibility requirements for premium consumer electronics.

“Shin-Etsu G-330 enabled us to achieve our ‘professional-grade tactile feel’ design goal. Even when shooting in extreme climates, users experience consistent and precise operation.”
— Optical Mechanical Design Department, Leading Imaging Equipment Manufacturer