Precision Gears & Custom Assemblies for OEM Applications
Made in New York since 1950.
We specialize in the design and manufacture of high-quality precision gears and custom gear assemblies for OEMs worldwide. Our solutions serve industries that demand reliability, performance, and consistency. We offer both standard inch and metric components, as well as fully customized solutions tailored to exact performance and application requirements.
Our core product line includes spur gears, bevel and miter gears, gear racks, worm gear pairs, sector gears, precision gearboxes, differentials, speed reducers, and motion control components. Manufactured to AGMA 8–13 and ISO 5–9 tolerances, our gears are available in pitches from 120 to 16 DP and metric modules from 0.3 to 3.0, with pressure angles of 14.5° and 20°. Whether your application calls for high-efficiency power transmission or precise motion control, our gears are built for strength, accuracy, and durability.
Quality is built into every step of our process. Gear cutting, assembly, and inspection are supported by a Class 10,000 clean room, and our finishing services are completed at NADCAP-certified and customer-approved facilities. Our experienced engineering team provides design consultations, value engineering, and customization support to ensure your product meets performance, cost, and manufacturability goals.
For less demanding projects, we also offer commercial-grade components that maintain dependable functionality while reducing lead times and costs. These options provide an ideal balance of value and performance, especially when ultra-high precision is not required.
We work with a wide range of materials, including aluminum, brass, bronze, stainless steel, titanium, and high-performance alloys. In addition, we produce plastic gears—both molded and machined—using engineering-grade thermoplastics such as Acetal, Nylon, and Polycarbonate. Whether your project demands tight tolerances or cost-effective durability, we deliver trusted components tailored to your specific needs. Click here to learn more about our manufacturing capabilities.
Spur Gears
Available In:
Materials: Stainless Steel, Aluminum, Brass, Nylon, Acetal, BakelitePitch: 16 - 120
Module: 0.4 - 3
Pressure Angle: 14.5 & 20°
Spur gears are the simplest and most widely used type of gear, featuring straight teeth that are cut parallel to the shaft axis. Spur gears are known for their efficiency, reliability, and ease of design. At SDP/SI, we offer a broad selection of precision and commercial-grade spur gears in both inch and metric sizes, manufactured to AGMA and ISO quality standards. Our offerings include external spur gears as well as internal spur gears and rack and pinion systems. These gears are ideal for transmitting rotary motion in a variety of applications, from industrial automation to sensitive instruments and control systems. Available in fine to medium pitches and materials like stainless steel, aluminum, brass, and acetal, our spur gears can be customized to meet specific performance requirements, ensuring dependable operation in even the most demanding environments.
Anti-Backlash Gears
Available In:
Materials: Stainless Steel, AluminumPitch: 24 - 120
Pressure Angle: 20°
Anti-backlash gears are specialized components designed to eliminate or significantly reduce backlash: the slight gap or play between meshing gear teeth that can affect positioning accuracy. These gears are essential in precision applications such as robotics, instrumentation, and motion control systems where high accuracy and repeatability are critical. At SDP/SI, our fine-pitch anti-backlash gears are engineered with stainless steel spring mechanisms that maintain constant tooth engagement by applying adjustable tension between gear halves. While the anti-backlash feature can be applied to many gear types, spur gears are the most common due to their straightforward design and frequent use in high-precision setups. SDP/SI offers anti-backlash gears in a variety of hub styles, including clamp, pin, and our proprietary Fairloc® hub system, which provides secure mounting with minimal shaft distortion. Whether you’re designing a new system or upgrading an existing one, our anti-backlash gears help ensure smooth, accurate motion with virtually no lost motion.
Composite Spur Gears
Available In:
Materials: Cast Nylon with Stainless Steel CorePressure Angle: 14.5° & 20°
Pitch: 48
Composite spur gears offer a high-performance, lightweight alternative to traditional metal gears, making them ideal for demanding applications where weight reduction, noise control, and chemical resistance are critical. At SDP/SI, our composite gears are engineered with a non-metallic gear body cast around a knurled metal core, providing a strong, durable interface between gear and shaft while maintaining low mass. These gears are capable of running at high speeds without lubrication, helping to reduce maintenance and system complexity. Their inherent properties help to minimize noise, vibration, and shock, making them well-suited for applications in robotics, medical equipment, and high-speed machinery. Corrosion- and chemical-resistant, composite gears also resist moisture absorption, making them reliable in harsh or humid environments. In many cases, composite spur gears can replace stainless steel gears while still handling high torque loads, offering a cost-effective and performance-driven solution for modern gear-driven systems.
Bevel Gears
Available In:
Materials: Stainless Steel, Aluminum, Brass, Nylon, AcetalPitch: 24 - 48
Module: 0.5 - 3
Pressure Angle: 20°
Bevel gears are used to transmit motion and power between intersecting shafts, typically set at right angles, though other shaft angles can be accommodated depending on the design. The defining feature of bevel gears is their cone-shaped pitch surface, which allows for smooth meshing at a variety of angles. At SDP/SI, we offer precision and commercial-grade bevel gears in both inch and metric sizes, designed for reliable performance in demanding applications such as automation equipment, medical devices, and industrial machinery. Standard gear ratios up to 4:1 are commonly available, with higher ratios possible for custom applications. Our bevel gears are manufactured from high-quality materials including stainless steel, brass, and acetal, and are available in a variety of configurations to suit both standard and custom designs. Whether you're creating a new drive system or refining an existing one, SDP/SI’s bevel gears provide accurate, efficient power transmission with the durability required for long-term operation.
Fairloc® Bevel Gears
Available In:
Materials: Stainless Steel, AluminumPitch: 48 - 72
Pressure Angle: 20°
Bore Size: 1/8, 3/16, 1/4
Precision Fairloc® Bevel Gears are engineered for high-performance applications requiring accurate alignment, secure mounting, and minimal shaft distortion. These gears feature integrated Fairloc® hubs, which use a unique clamping system with socket head cap screws to provide a reliable, slip-free connection without damaging the shaft. Ideal for transmitting motion between intersecting shafts (typically at 90° angles), Fairloc® bevel gears offer precise torque transfer in compact assemblies. Manufactured to tight tolerances, they require a controlled shaft fit, with a recommended bore-to-shaft clearance of .0001” to .0008”. Each set is sold as a matched pair, ensuring optimal meshing and performance. For more specialized needs, custom options are available by request, including alternate tooth counts, pitch sizes, bore dimensions, and passivation treatments. Precision Fairloc® Bevel Gears are an excellent choice for engineers designing critical motion control or instrumentation systems where stability, repeatability, and easy installation are essential.
Miter Gears
Available In:
Materials: Stainless Steel, Aluminum, Brass, AcetalPitch: 16 - 72
Module: 0.5 - 3.5
Miter gears are a specific type of bevel gear designed to operate in matched pairs, transmitting power between intersecting shafts, most often set at 90 degrees. What distinguishes miter gears is their 1:1 gear ratio, with each gear having the same number of teeth and identical dimensions. This allows for efficient and balanced motion transfer where the input and output rotational speeds remain constant, but the direction of rotation is changed. Miter gear sets are commonly used in applications such as inspection equipment, automation systems, and mechanical assemblies requiring precise directional changes without altering speed. At SDP/SI, we offer high-quality miter gears in both inch and metric sizes, manufactured from durable materials and engineered for accuracy, smooth operation, and long-term reliability in demanding environments.
Gear Racks
Available In:
Materials: Stainless Steel, Aluminum, Nylon, AcetalPitch: 1/20 - 120
Module: 0.3 - 3
Circular Pitch: 2 & 5
Pressure Angle: 20°
Gear racks are the linear counterpart in a rack and pinion system, designed to convert rotary motion into smooth, accurate linear movement. At SDP/SI, our precision racks feature uniformly cut teeth that mesh seamlessly with a rotating pinion gear, ensuring consistent motion control with minimal backlash. Ideal for applications requiring accurate and exact positioning, such as automation, robotics, and inspection systems, our gear racks are available in both inch and metric sizes, and manufactured from high-quality materials to meet tight tolerances. Whether used in horizontal or vertical configurations, SDP/SI gear racks deliver dependable performance and repeatable accuracy in even the most demanding environments.
Helical Gears
Available In:
Materials: Stainless Steel, Aluminum, Hardened SteelPitch: 48
Module: 1 - 2
Pressure Angle: 20°
Helical Gears are similar in function to spur gears but offer distinct performance advantages due to their unique tooth design. Helical gears feature teeth that are twisted along a helical path in the axial direction. This results in a smooth and staggered engagement that resembles a sequence of overlapping spur gears across the face width. This design enhances performance in two key ways. First, tooth strength is increased, as the helical wrap-around configuration provides a longer base of support. Second, the contact ratio is higher, thanks to the axial tooth overlap, which allows multiple teeth to engage at once. These factors contribute to greater load-carrying capacity, smoother operation, and quieter performance compared to spur gears of the same size. At SDP/SI, our helical gears are engineered for precision and durability in demanding applications where strength, efficiency, and reduced noise are critical. They're ideal for use in high-speed drives, automation systems, and gearboxes where enhanced power transmission and performance are required.
Internal Gears
Available In:
Materials: Stainless Steel, Aluminum, BrassPitch: 24 - 96
Module: 0.5 - 1
Pressure Angle: 20°
Internal Gears offer unique advantages for compact, high-performance gear systems, particularly in planetary gear trains and precision instrument assemblies. Spur and helical gears can also be manufactured in an internal form, where the teeth are cut on the inside surface of a gear ring. This configuration allows an internal gear to mesh with a standard external gear, expanding the possibilities for efficient and space-saving mechanical designs. Internal gears bring several benefits to complex gear arrangements. First, they are well-suited for compact systems, as the center distance between mating gears is smaller than in external gear setups. Second, the design allows for a high contact ratio, providing smoother operation and improved load distribution. Third, the gear geometry—where a convex external gear tooth contacts a concave internal gear surface—promotes excellent surface endurance, making the system more resistant to wear under high loads. Whether you're designing a planetary gearbox or a custom motion control system, internal gears offer the versatility, performance, and reliability to meet your design goals.
Worm Gear Pairs
Available In:
Materials: Stainless Steel, Bronze, Steel, Aluminum, Nylon, AcetalPitch: 24 - 64
Module: 0.5 - 3
Worms and Worm gears are a type of gear set consisting of a worm (a screw-like gear) and a mating worm gear, which mesh together on shafts oriented at 90°. This configuration allows for compact, high-ratio speed reduction in a single stage. Worm gear sets from SDP/SI are engineered for smooth, quiet operation and enhanced load capacity, thanks to their line-contact design—an advantage over traditional crossed-helical gears. In many applications, worm gear sets also offer self-locking functionality, making them ideal for lifting, positioning, and holding tasks without the need for additional braking systems. Available in a wide range of ratios and materials, SDP/SI worms and worm gears are trusted in precision motion systems across robotics, medical devices, and industrial automation.
Screw Gears
Available In:
Materials: Aluminum, Bronze, Carbon Steel, NylonModule: 1.5 - 3
Screw gears are a type of helical gear used to transmit motion between non-parallel, non-intersecting shafts—typically set at a 90° angle. Their smooth, quiet operation and compact design make them suitable for moderate-load, low-speed applications where space constraints or specific shaft configurations are a concern. Unlike worm gears, screw gears do not offer self-locking capabilities, but they provide efficient power transmission with less sliding friction. Available in both left-hand and right-hand helix angles, screw gears must be paired with a gear of opposite hand for proper meshing. They are commonly found in conveying systems, packaging equipment, and precision instruments.
Differentials
Available In:
Materials: Stainless SteelPitch: 72 - 96
Differentials are advanced mechanical components designed to distribute torque between two output shafts, allowing them to rotate at different speeds—essential in systems that require smooth turning or load balancing between axles. At SDP/SI, our expertise extends beyond precision gears to include the design, engineering, and manufacturing of custom differentials, gearboxes, and planetary gearheads. Built to meet the tight tolerances and performance demands of industries such as aerospace, defense, and medical devices, our differential assemblies are engineered for precision, durability, and reliability under dynamic load conditions. Whether used in robotics, mobility systems, or complex mechanical assemblies, SDP/SI differentials are designed to ensure smooth torque distribution and optimal performance in even the most challenging environments.
Differential End Gears
Available In:
Materials: Stainless Steel, AluminumPressure Angle: 20°
Pitch: 48 - 96
Differential End Gears are critical components used to complete differential assemblies, ensuring smooth and precise torque transfer between output shafts. At SDP/SI, we manufacture small stainless steel differentials in 96, 72, 64, and 48 pitch, all available as standard catalog items. To streamline assembly and ensure performance, stainless steel or anodized aluminum end gears can be ordered and assembled to the differential at no additional charge when purchased together. These end gears are built to high precision standards, with a maximum backlash of 10 arc minutes, supporting tight motion control and consistent gear engagement. Whether you're designing for robotics, automation, or instrumentation, SDP/SI’s differential end gears provide a reliable solution for accurate power distribution in compact systems.
Gear and Dial Hubs
Available In:
Materials: Stainless Steel, AluminumGear and Dial Hubs provide secure, accurate mounting for gears, dials, and other rotating components in motion control systems. At SDP/SI, we offer precision stainless steel hubs in three styles: clamp, pin, and our exclusive Fairloc® hub. Each style is designed to deliver consistent alignment and ease of installation across a wide range of shaft sizes and applications. The Fairloc® hub provides a non-marring, low-distortion hold and is ideal for precision assemblies requiring controlled shaft tolerances, with a recommended clearance fit of .0001” to .0008” between the bore and the shaft. For lighter-duty or space-constrained setups, we also offer anodized aluminum pin-type gear hubs, perfect for use with hubless stamped or molded gears, as well as disc and drum dials. Whether you need high-strength retention or easy repositioning, SDP/SI’s gear and dial hubs offer the flexibility, precision, and reliability demanded by today's electromechanical designs.
Nonmetallic Gear Blanks
Available In:
Materials: Acetal with Aluminum or Brass InsertGear blanks are unfinished components that serve as the foundation for creating custom gears. At SDP/SI, we offer high-quality gear blanks used to manufacture a wide variety of gear types, including spur gears and internal gears. In spur gears, teeth are cut along the outer diameter of the blank, while internal gears are produced by cutting teeth on the inside diameter. Our gear blanks are available in multiple configurations, providing a versatile starting point for engineers looking to create specialized components tailored to specific application requirements. Whether you're prototyping a new design or replacing a legacy part, SDP/SI also offers standard gears in a wide range of tooth counts, bore sizes, and pitches, giving you the flexibility to choose between ready-to-use components and customizable blanks for your motion control or power transmission systems.
Gear Clamps
Available In:
Materials: Stainless Steel, SteelGear Clamps, also known as shaft/hub clamps, are essential components used to securely fasten split hub gears and pulleys to shafts in a wide range of motion control and power transmission systems. At SDP/SI, we offer both precision and commercial-grade clamps in various configurations, including one-piece and two-piece balanced constructions, as well as reduced clearance radius designs for space-constrained applications. These clamps are ideal for providing a strong, uniform hold without damaging the shaft surface, and are particularly useful in assemblies requiring easy repositioning or frequent maintenance. Our screw-type gear clamps are available for shafts as small as 1/16 inch, making them suitable for everything from delicate instrumentation to industrial machinery. Designed for versatility and ease of use, SDP/SI gear clamps enable quick adjustment, reliable alignment, and simple removal of the mounted component without the need for complex tools or procedures.
Pinion Shafts & Pinion Wire
Available In:
Materials: Brass, SteelPitch: 24 - 64
Module: 0.4 - 0.8
Pressure Angle: 20°
Pinion shafts and pinion wire are essential components for building custom gear solutions, especially when standard stock gears don’t meet application requirements. At SDP/SI, we offer pinion wire in both brass and steel, extruded for precision and ease of machining into custom spur gears. Pinion wire is available in pitches 64, 48, 44, 32, and 24 (Modules 0.4, 0.5, and 0.8) with 14½° and 20° pressure angles, and comes in 1, 3, and 5-foot lengths as standard catalog items—other lengths can be supplied upon request. In addition to pinion wire, we provide steel spur gear stock in pitches 48, 32, 24, and 20 (Modules 0.8 and 1), ideal for machining custom spur gears and pinion shafts. These versatile stock materials are perfect for prototyping, repairs, or low-volume production, offering flexibility and precision in motion control, automation, and mechanical design projects.
Spur Gear Stock
Available In:
Materials: Carbon SteelPitch: 20 - 48
Pressure Angle:14.5° & 20°
Spur gear stock provides a versatile solution for custom gear cutting and prototyping. Supplied as unfinished gear blanks or bar stock with pre-cut teeth, it allows engineers and machinists to machine bore sizes, hub lengths, or keyways to meet specific design requirements. Spur gear stock features straight teeth and transmits motion between parallel shafts efficiently, making it ideal for a wide range of applications, from automation equipment to mechanical drives. Available in various materials, pressure angles, and pitch options, spur gear stock offers flexibility for both high-volume production and low-run custom builds.
Internal & External Splines
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Materials: Carbon Steel, Stainless SteelExternal and internal splines are essential components for transmitting torque while maintaining precise shaft-to-hub alignment. External splines are machined onto a shaft, while internal splines are cut into a mating component—together forming a high-strength, low-backlash connection ideal for rotational power transfer. Commonly used in drive systems, couplings, and motion control assemblies, splines offer reliable engagement with the ability to support axial movement under load. SDP/SI offers a range of precision-engineered splined components and supports custom configurations to meet demanding application requirements in aerospace, automation, and high-performance machinery.
Cluster Gears
Available In:
Materials: Stainless SteelPressure Angle: 20°
Pitch: 48 - 80
Cluster gears are compact assemblies consisting of multiple spur gears of varying diameters mounted on a single shaft. This integrated configuration allows for efficient and synchronized power transmission across multiple gear ratios within a confined space. Commonly found in gearboxes, especially in automotive and industrial applications, cluster gears enable smooth shifting and optimized torque transfer across a range of speeds and loads. At SDP/SI, cluster gears are available in custom or modified configurations, designed to meet specific performance requirements and space constraints. By combining multiple gears into one shaft-mounted unit, these assemblies reduce part count, improve alignment, and ensure precise meshing within complex gear systems.