At their core, friction shims are used to enhance the coefficient of friction between jointed components, allowing for significantly higher torque transmission without increasing bolt preload or redesigning the mating parts. This means engineers can avoid using oversized fasteners or heavier parts, which is especially beneficial in industries where space and weight are at a premium.
Applications Across Critical Industries
The value of custom metal shims goes far beyond a simple mechanical interface. Industries such as automotive, aerospace, wind energy, robotics, turbines, and high-precision machining have all adopted friction shims to solve torque transfer problems. Even medical, dental, and paper processing equipment manufacturers are integrating this technology to improve assembly performance and long-term durability.
For example, in electric vehicle drivetrains, where compact yet powerful torque transfer is crucial, friction shims allow for optimal performance without redesigning the entire gearbox. Similarly, in wind turbines and aerospace structures, they prevent micro-movement between components and help maintain alignment under high loads and environmental stresses.
How Friction Shims Work
These precision-engineered shims typically feature a metallic base (often steel, stainless steel, or aluminum) coated with a textured surface, like diamond particles embedded in a nickel matrix. This composite surface greatly increases friction when clamped between two mating parts. When torque is applied, the rough surface resists slippage and helps maintain alignment and torque transmission even under vibration, thermal cycling, or repeated load changes.
This video demonstration of Ni-Grip Friction Shims provides a great overview of how they are manufactured and integrated into mechanical assemblies. You’ll see how 3M’s high-performance coatings are bonded to metal substrates to create a friction interface that performs reliably under extreme loads.
Materials, Sourcing, and Surface Technology
Manufacturing quality is key, and engineers seeking reliable solutions often turn to companies with deep expertise in materials and coatings. For example, a metal finishing company in NJ like Surface Technology, Inc. (STI) is known for producing precision shims that are both durable and customizable. Whether the application calls for a lightweight aluminum substrate or the strength of stainless steel, STI offers flexibility in base material and coating composition.
3M friction shims are also a popular choice, as they are known for consistent quality and high-performance coatings that integrate well into both OEM and retrofit designs. Combined with STI’s capabilities, engineers can source shims tailored to specific loads, part geometries, and environmental conditions.
Friction shims are a smart, cost-effective way to improve joint integrity, increase torque transfer, and enhance the performance of bolted metal assemblies without redesigning the entire system. From high-speed robotics to wind turbine gearboxes, these small but powerful components are transforming the way engineers approach joint design.
Friction Shims from Surface Technology (STI) are available in steel, stainless steel, or aluminum shim base metals, with any version of STI’s proprietary Composite Diamond Coatings (CDC), depending on the level of grip required for your application.