What Is the Ultra-Slim Rotary Damper “SR100”? – Industry’s Smallest Rotary Damper

Do you face these issues when miniaturizing your products?

• Existing small-diameter rotary dampers lack sufficient torque…
• Insufficient torque makes the product feel cheap, undermining its premium feel…
• Standard sizes are too large, compromising design aesthetics…
• Limited industry standard options force design compromises…

TOK’s newly developed ultra-slim rotary damper “SR100” achieves an industry-leading torque of 1.4 N·m despite its extremely slim size with an outer diameter of just 8 mm.
Developed as a product symbolizing our 100th anniversary technological prowess, the ultimate rotary damper “SR100” expands product design freedom like never before, contributing to further enhancing the value of our customers’ products.

This article introduces the development background, basic specifications, and differences from standard rotary dampers of SR100.

Development Background and Basic Specifications of the Ultra-Slim Rotary Damper SR100

Rotary dampers are essential components for enabling smooth, controlled motion when opening and closing lids or doors. However, standard-size rotary dampers, while capable of providing sufficient torque, are often difficult to install in products with limited space. On the other hand, small-diameter rotary dampers may fit within confined spaces but frequently fail to deliver adequate torque. As modern product design increasingly demands compact dimensions and refined aesthetics, there has been growing concern that conventional rotary dampers cannot fully meet these requirements. With the belief that designers should not have to sacrifice smooth, controlled motion due to space limitations, TOK brought together its accumulated engineering expertise to develop the ultra-slim rotary damper SR100, unveiled at the milestone of its 100th anniversary.

SR100 makes it possible to incorporate smooth, controlled motion even in products where rotary dampers were previously excluded due to space constraints. By enabling slow, controlled movement within extremely limited installation space, SR100 supports the realization of products that combine both sophisticated design and functional performance. Despite its ultra-slim size, SR100 delivers a torque of 1.4 N·m, ensuring safe and reliable operation.

The detailed basic specifications of the ultra-slim rotary damper SR100 are as follows:

• Outer diameter: Φ8 mm
• Torque: 1.4 N·m
• Opening angle: 110°
• Durability: 10,000 cycles
• Operating temperature range: 0°C to 40°C
• Material: SUS

Key Differences Between the Ultra-Slim Rotary Damper SR100 and Standard Rotary Dampers

The most significant difference between the ultra-slim rotary damper SR100 and standard rotary dampers lies in its outer diameter. Many of TOK’s standard rotary dampers have an outer diameter of 18 mm, whereas SR100 features an exceptionally compact 8 mm diameter, comparable in size to a pen.

Despite its ultra-slim form factor, SR100 delivers outstanding damping performance. In terms of damper torque, it significantly outperforms TOK’s conventional rotary dampers (TD73 / TD75 / TD148 series, outer diameter Φ11 mm, torque 0.3 N·m), achieving a high torque of 1.4 N·m. This allows the SR100 to provide reliable and stable support even in compact product designs.

In addition, with a focus on reducing environmental impact, the amount of silicone oil used inside SR100 has been reduced by approximately 80% compared to conventional models. Operating purely through mechanical principles without any electrical control, SR100 supports sustainable manufacturing by offering a durable, energy-free damping solution.

Summary of What Is the Ultra-Slim Rotary Damper “SR100”? – Industry’s Smallest Rotary Damper

SR100 is an ultra-slim rotary damper that significantly expands design flexibility. Despite its extremely compact 8 mm outer diameter, it achieves a high torque of 1.4 N·m, representing a technological advancement previously unavailable in rotary dampers. This innovative design has received strong external recognition, including the Good Design Award 2025.
SR100 is currently patent pending in Japan, with plans to pursue international patent protection in the future.

SR100 was developed to demonstrate TOK’s technical approach and development capabilities. As such, it is not currently available for sale. However, we are always open to consultations regarding custom design and development tailored to your specific requirements.

If you are looking for a small-diameter rotary damper for your application, please feel free to contact TOK for further information.