Fairloc® Fastening System – Secure, Reliable, and Easily Adjustable
SDP/SI's Fairloc® Fastening System is a revolutionary solution for secure, non-marring mounting of components without the need for set screws or clamps. The system allows components to be easily repositioned with a single hex key adjustment, ensuring reliable and repeatable performance. Designed to prevent shaft damage, Fairloc® provides outstanding holding power while simplifying the assembly process.
Ideal for high-precision applications, Fairloc® enables quick adjustments, reducing downtime and offering superior reliability in both low and high-torque environments. Whether used in motors, drives, or other mechanical systems, this versatile system eliminates the need for traditional fastening methods, making it a cost-effective and efficient choice for engineers seeking flexibility and dependability.
Fairloc® Fastening Hub System Video
This video explans the Fairloc® Fastening Hub System, showing the benefits of using Fairloc® for your rotating components such as gears. Easily adjusted, the Fairloc® hub replaces set screws and clamps: components can be repositioned with a single hex key adjustment, it will not mar the shaft, and offers outstanding reliability!
| Fastening Method | Shaft Remains Smooth | Self-Contained | Component is Fully Supported | Easy Adjustment | Can be Pinned if Desired |
| Clamps | YES | NO | NO | YES | NO |
| Fairloc ® | YES | YES | YES | YES | YES |
| Keys | NO | NO | NO | NO | NO |
| Pins | NO | NO | NO | NO | YES |
| Set Screws | NO | NO | NO | NO | YES |
Fairloc® Hubs are Used in Custom Designs
At SDP/SI, our experienced application engineers are ready to help with everything from basic part selection to complex custom solutions. Whether you're looking for the ideal component, value-added services, or complete design and manufacturing support, we provide expert guidance every step of the way. We’re committed to delivering high-quality engineering services that meet your performance and cost requirements.
Our products are used in a wide range of industries and applications, including aerospace components, aircraft instrumentation, medical equipment, robotics, optical systems, power drives, military fire control systems, and CNC machinery.
Fairloc® Torque Data
Fairloc® is a unique fastening system integrated directly into the hub of a component, providing a secure, non-marring connection to the shaft. Its performance, including the relationship between clamp screw torque and slip torque, is demonstrated in application-specific graphs—such as those using stainless steel gears on stainless steel shafts. For optimal results, it's important to maintain tight tolerances between the shaft and bore, and to lubricate the clamping screw with molybdenum disulfide grease to enhance holding strength and reliability.
Our products are used in a wide range of industries and applications, including aerospace components, aircraft instrumentation, medical equipment, robotics, optical systems, power drives, military fire control systems, and CNC machinery.
CAUTION: Do Not Tighten Screws Without Shaft in the Bore. This will create a permanent set of wedge section which will prevent the shaft from going in.
**Hover images to enlarge**
Figure 1 – shows the torque at which the sample Fairloc® gears started to slip on the shaft. All gears and shafts were made of 303 Stainless Steel. Gear bores were within +.0003 inch of nominal values. Shafts had surface finishes of 16 micro-inch maximum and were within. -.0002 inch of the nominal diameters.
Figure 2 – compares the slip torques for different values of the clamping screw fastening torques.
Figure 3 – shows the torque at which the sample Fairloc® gears started to slip on the shaft. All gears and shafts were made of 303 Stainless Steel. Gear bores were within +0.0075 mm of nominal values. Shafts had surface finishes of 0.4µm maximum and were within. -0.005 mm of the nominal diameters.
Figure 4 – compares the slip torques for different values of the clamping screw fastening torques.
Fairloc® Hubbed Anti-Backlash Gears
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Available In:
Materials: Stainless Steel, AluminumPitch: 48 - 120
Pressure Angle: 20°
SDP/SI's Fairloc® Hubbed Anti-Backlash Gears combine precise motion control with the convenience of the Fairloc® keyless fastening system. Designed to reduce or eliminate gear lash in sensitive positioning applications, these gears feature a built-in Fairloc® hub for easy, non-marring installation and secure shaft connection. The result is a compact, reliable assembly that simplifies alignment, enhances repeatability, and minimizes vibration. Ideal for instrumentation, robotics, and motion systems, Fairloc® anti-backlash gears deliver smooth, quiet performance and quick adjustability without the need for set screws or keyways.
Fairloc® Mini-Lash Gears
Available In:
Materials: Stainless Steel, AluminumPitch: 64 - 120
Pressure Angle: 20°
SDP/SI's Fairloc® Mini-Lash Gears are compact anti-backlash gears designed for precision applications where space is limited and backlash control is essential. Featuring the built-in Fairloc® hub, they offer a secure, non-marring shaft connection and easy repositioning without set screws or keyways. These gears are ideal for light-load, high-accuracy systems such as miniature robotics, optical devices, and instrumentation. The combination of backlash compensation and Fairloc’s keyless fastening delivers smooth, reliable motion control in a small, efficient package perfect for tight mechanical assemblies.
Fairloc® Bevel Gears
Available In:
Materials: Stainless Steel, AluminumPitch: 48 - 72
Pressure Angle: 20°
Fairloc® Bevel Gears from SDP/SI offer precise angular power transmission with the added benefit of the Fairloc® hub for quick, secure, and non-marring shaft mounting. Ideal for right-angle gear arrangements, these gears ensure smooth torque transfer and easy alignment without the need for keyways or set screws. The built-in Fairloc® system allows for fast assembly and repositioning, making them perfect for use in applications requiring compact, high-precision motion—such as automation, test equipment, and robotics. This combination delivers long-lasting performance and simplified maintenance in demanding mechanical systems.
Fairloc® Plastic Spur Gears
Available In:
Materials: Acetal with Stainless Steel HubPitch: 24 - 72
Pressure Angle: 20°
Module: 0.5 - 1
SDP/SI's Fairloc® Plastic Spur Gears combine lightweight performance with the convenience of the patented Fairloc® hub, offering a secure, keyless fastening method that won’t damage the shaft. Ideal for applications requiring quiet operation and corrosion resistance—such as medical devices, laboratory equipment, and light-duty automation—these gears provide smooth, efficient power transmission in compact systems. The integrated Fairloc® hub allows for easy installation, precise repositioning, and reliable holding strength without the need for set screws or keyways, making them a versatile and maintenance-friendly choice for precision gear assemblies.
Fairloc® Stainless Steel Spur Gears
Available In:
Materials: Stainless SteelPitch: 24 - 48
Pressure Angle: 0.5 - 1
Module: 20°
Fairloc® Stainless Steel Spur Gears from SDP/SI deliver strength, precision, and easy adjustability in one integrated solution. Manufactured from durable stainless steel, these gears are ideal for applications requiring corrosion resistance and high torque capacity. The patented Fairloc® hub allows for fast, secure, and non-marring shaft attachment—eliminating the need for set screws or keyways and enabling quick repositioning. Perfect for robotics, automation, and instrumentation, SDP/SI’s Fairloc® stainless steel spur gears ensure long-lasting, reliable performance in demanding environments where accuracy and alignment are critical.
Fairloc® Miniature Bellows Couplings
Available In:
Materials: Brass, Bronze, SteelBore Size: 0.0625 in. (1mm) - 0.1250 in. (3mm)
Length: 0.853 in. (21.5mm) - 0.969 in. (24.5mm)
SDP/SI's Fairloc® Miniature Bellows Couplings offer precise, zero-backlash performance for small-scale motion control systems, with the added benefit of the Fairloc® hub for quick, non-marring shaft attachment. Designed to accommodate angular, axial, and parallel misalignments, these couplings provide excellent torsional rigidity and smooth torque transmission in compact assemblies. The integrated Fairloc® fastening system allows for fast, secure adjustments without keyways or set screws, making them ideal for use in precision equipment like miniature actuators, instrumentation, and medical devices where accuracy, repeatability, and reliability are critical.
Fairloc® Bellows Couplings
Available In:
Materials: Brass, Bronze, Stainless SteelBore Size: 0.120 in.(3mm) - 0.375 in.(12mm)
Length: 0.92 in.(23.4mm) - 1.31 in.(33.3mm)
Fairloc® Bellows Couplings from SDP/SI provide high torsional stiffness and zero-backlash performance for demanding motion control applications. With the patented Fairloc® hub integrated into each end, these couplings offer secure, non-marring shaft attachment and easy installation without keyways or set screws. Designed to accommodate angular, axial, and parallel misalignments, they are ideal for servo systems, encoders, and precision drives where smooth torque transmission and reliable positioning are essential. The combination of stainless steel bellows and Fairloc® fastening makes these couplings a durable, maintenance-friendly solution for dynamic, high-speed environments.
Fairloc® Neo-Flex Couplings
Available In:
Materials: Stainless Steel, NeopreneBore Size: 0.12 in. (3mm) - 0.25 in. (6mm)
Length: 1.264 in. (33.1mm) - 2.650 in. (67.3mm)
Fairloc® Neo-Flex Couplings from SDP/SI combine flexibility and torque control in a compact, vibration-resistant design. Featuring the patented Fairloc® hub, these couplings provide secure, non-marring shaft attachment and easy repositioning without the need for set screws or keyways. Neo-Flex Couplings are engineered to handle angular, axial, and parallel misalignments while dampening vibration and shock, making them ideal for servo motors, stepper systems, and dynamic motion applications. With precision performance and simplified installation, they offer a reliable, maintenance-friendly solution for high-performance mechanical systems.
Fairloc® Rigid Couplings
Available In:
Materials: Stainless SteelBore Size: 0.0900 in. (2.5mm) - 0.2498 in. (12mm)
Length: 5/8 in. (19mm - 38mm)
Fairloc® Rigid Couplings provide a precise, backlash-free connection for applications requiring firm, slip-free torque transmission between shafts. These couplings feature SDP/SI’s patented Fairloc® hub, which allows for quick installation, non-marring shaft engagement, and easy realignment—without the need for keyways or set screws. Ideal for high-precision systems where shaft misalignment is minimal, Fairloc® Rigid Couplings ensure secure, reliable performance and are well-suited for use in automation, robotics, and instrumentation. Trust SDP/SI for durable, maintenance-friendly couplings engineered to simplify assembly and enhance system accuracy.
Fairloc® Rigid Couplings
Available In:
Materials: Stainless SteelBore Size: 0.0900 in. (2.5mm) - 0.2498 in. (12mm)
Length: 5/8 in. (19mm - 38mm)
Fairloc® Rigid Couplings provide a precise, backlash-free connection for applications requiring firm, slip-free torque transmission between shafts. These couplings feature SDP/SI’s patented Fairloc® hub, which allows for quick installation, non-marring shaft engagement, and easy realignment—without the need for keyways or set screws. Ideal for high-precision systems where shaft misalignment is minimal, Fairloc® Rigid Couplings ensure secure, reliable performance and are well-suited for use in automation, robotics, and instrumentation. Trust SDP/SI for durable, maintenance-friendly couplings engineered to simplify assembly and enhance system accuracy.
Fairloc® Aluminum Timing Pulleys
Available In:
Materials: Aluminum AlloyProfile: MXL, GT®, HTD®
Pitch: 0.08 - 3.00
Fairloc® Aluminum Timing Pulleys offer a lightweight, precision-engineered solution for high-performance motion systems. Integrated with SDP/SI’s patented Fairloc® hub, these pulleys provide a secure, keyless shaft attachment that won’t mar the shaft and allows for quick, repeatable adjustments. Made from high-strength aluminum, they are ideal for reducing inertia while maintaining excellent strength and durability. Perfect for use in automation, robotics, and servo systems, Fairloc® timing pulleys simplify assembly and alignment while delivering smooth, reliable belt drive performance in demanding applications.
Fairloc® Plastic Timing Pulleys
Available In:
Materials: Polycarbonate, Fiberglass, Aluminum AlloyProfile: XL, HTD®
Pitch: 1/5", 5mm, 5.08mm
Fairloc® Plastic Timing Pulleys from SDP/SI provide lightweight, corrosion-resistant performance with the added advantage of the patented Fairloc® hub for secure, keyless shaft mounting. Ideal for low-to-moderate torque applications, these pulleys are molded from durable engineering plastics and are well-suited for environments where metal components are not desirable. The built-in Fairloc® hub ensures easy, non-marring installation and quick repositioning, eliminating the need for set screws or keyways. Perfect for medical devices, lab equipment, and light-duty automation, these pulleys offer dependable, maintenance-friendly operation in compact, precision-driven systems.
Fairloc® Shaft Reducers & Extenders
Available In:
Materials: Stainless SteelBore Size: 0.1200 in. (3mm) - 0.4998 in. (12mm)
Shaft Length: 1 in. (25mm - 30mm)
Fairloc® Shaft Reducers and Extenders from SDP/SI offer a precise and convenient solution for adapting or extending shaft diameters in tight tolerance applications. Featuring the patented Fairloc® hub, these components ensure secure, keyless, and non-marring installation—ideal for quick adjustments without the need for set screws or keyways. Machined from high-quality materials, they are designed for maximum concentricity and balance, making them perfect for use in instrumentation, automation, and prototype development. With easy installation and reliable performance, Fairloc® shaft reducers and extenders help simplify system design and enhance shaft compatibility.
Fairloc® Shaft Collars
Available In:
Materials: Brass, Stainless SteelBore Size: 0.12 in. (3mm) - 0.75 in. (20mm)
Outer Diameter: 0.433 in. (11mm) - 1.496 in. (38mm)
Fairloc® Shaft Collars offer a secure, non-marring method for positioning, spacing, or limiting the movement of components on a shaft. Unlike traditional set screw collars that can damage the shaft, the Fairloc® hub design provides a reliable grip without deformation, using only a single hex key for adjustment. Available from SDP/SI in a variety of materials and sizes, these collars are easy to install and ideal for high-precision applications where alignment, balance, and repeatability are critical. Perfect for use in automation, medical devices, and prototyping environments.
Fairloc® Gear & Dial Hubs
Available In:
Materials: Stainless SteelBore Size: 0.0900 in. (2.5mm) - 0.2498 in. (8mm)
Hub Diameter: 0.437 in. (11mm) - 0.530 in. (17mm)
Fairloc® Gear and Dial Hubs provide a convenient and secure method for mounting gears, dials, and other components to a shaft without the need for keyways or set screws. Utilizing the patented Fairloc® hub design, these hubs enable easy repositioning and alignment while maintaining a tight, non-marring grip. Ideal for prototyping and precision assemblies, they simplify installation and improve repeatability. Offered by SDP/SI in various sizes and configurations, Fairloc® hubs help reduce assembly time while enhancing overall system reliability.