SDP/SI manufactures precision HTD® timing belt pulleys and drive components for OEM and industrial applications, offering online ordering, engineering support, CAD resources, custom belt widths, and scalable solutions from prototype development through high-volume production. (read more)

SDP/SI offers metric synchronous timing belts and drive components online, featuring extensive inventory, fast shipping, engineering support, CAD resources, and custom solutions for automation, robotics, aerospace, medical, and industrial applications. (read more)

SDP/SI offers a wide range of stock mechanical components online, including timing pulleys, timing belts, precision gears, bearings, couplings, shafting, and gearboxes. Standard inch and metric products ship quickly, supported by engineering expertise, CAD models, and selector tools. (read more)

SDP/SI offers a wide range of stock mechanical components online, including gears, pulleys, timing belts, bearings, couplings, shafting, motors, and gearboxes. Standard inch and metric products ship quickly, supported by engineering expertise, CAD models, and selector tools. (read more)

SDP/SI offers a wide range of stock mechanical components online, including precision machined and molded gears, timing pulleys, timing belts, bearings, couplings, shafting, and gearboxes. Standard inch and metric products ship quickly, supported by engineering expertise, CAD models, and selector tools. (read more)

SDP/SI offers precision synchronous timing belts and drive components online, featuring extensive inventory, fast shipping, engineering support, CAD resources, and custom solutions for automation, robotics, aerospace, medical, and industrial applications. (read more)

SDP/SI manufactures precision molded universal joints engineered for reliable motion control. Lightweight, durable, and corrosion resistant, these cost-effective joints provide vibration dampening, electrical insulation, and customizable configurations for medical, automation, aerospace, and industrial applications. (read more)

SDP/SI, a U.S. manufacturer since 1950, provides precision mechanical solutions for motion control applications. Its miniature Fairloc® bellows couplings deliver zero backlash, vibration damping, and reliable torque transmission, supported by engineering expertise, online design resources, and custom manufacturing capabilities. (read more)

SDP/SI delivers maintenance-free bearing solutions engineered for demanding environments. Lightweight, corrosion-resistant, and easy to install, these self-aligning plastic bearings provide reliable performance, vibration dampening, and long service life for medical, industrial, and automation applications worldwide. (read more)

SDP/SI manufactures precision bevel gears featuring the proprietary Fairloc® Hub design, delivering accurate, repeatable torque transmission with easier assembly and improved reliability. Available in multiple pitches, modules, and materials, these gears support demanding medical, aerospace, defense, and automation applications. (read more)

Chronic assembly problems vanished when a medical device OEM upgraded to SDP/SI’s Fairloc® hub gears, delivering exact alignment, consistent performance, and reliability. Learn more. (read more)

Explore SDP/SI’s precision-engineered standard universal joints designed for demanding motion control applications. Access CAD models, specifications, and online ordering with expert engineering support. Partner with SDP/SI to accelerate development, improve performance, and scale production with confidence today. (read more)

Explore SDP/SI’s precision-engineered standard shaft couplings designed for demanding motion control applications. Access CAD models, specifications, and online ordering with expert engineering support. Partner with SDP/SI to accelerate development, improve performance, and scale production with confidence today. (read more)

SDP/SI Fairloc® shaft collars provide superior holding power, shaft protection, and precise adjustment for motion control applications, with standard and custom inch and metric configurations. (read more)

These shaft reducers and extenders from SDP/SI eliminate the need for special shafting. There are 20 inch and 27 metric size stainless steel adapters, identified as the S52FCY-... inch series and S52FCYM... metric series, are high precision, with tight tolerances on bores, shank and bore/shank concentricity. The female end of the adapter is designed to fit shaft diameters r... (read more)

The SDP/SI Shaftloc® fastening system stands out for its simplicity and strength. With just two precision-engineered parts, it delivers superior torque transmission through its asymmetrical thread profile. This innovative design amplifies clamping forces, ensuring secure, reliable shaft-to-component connections while reducing complexity, installation time, and maintenance need... (read more)

SDP/SI offers precision ground shafting in undersize, nominal, and oversize diameters to suit your application. The A 7X 1-… series, made from 303 stainless steel, is available online in lengths from 1" to 36" and diameters from 0.0311" to 0.7500". Need custom lengths, diameters, or grooving? Call us! (read more)

As a leader in providing drive solutions, SDP/SI partners with companies to develop integrated systems that meet their specific needs. Offering a comprehensive selection of high-quality products, SDP/SI frameless motors are designed to fit easily into smaller machines requiring precision, high efficiency, low inertia, and high torque density. Learn more. (read more)

Stock Drive Products / Sterling Instrument offers a comprehensive selection of bearings, suitable for a wide variety of applications. Select No Shield, Single Shield, Double Shield and type of lubrication, various materials, and ABEC specifications. Stock components are available online, download product detail and 3D CAD models, Shop SDP-SI! (read more)

Stock Drive Products/Sterling Instrument stock gear racks are available in a wide range of pitches, modules, and materials, including steel, hardened steel, brass, stainless steel, machined cast nylon, molded acetal, and aluminum. Shop SDP/SI - One single source! (read more)

Uniquely designed flexible coupling provides problem solving benefits. SDP/SI adds flexible couplings that resolve vibration while operating in a high-speed servo system at high gain settings. Satisfy all your mechanical component requirements at SDP/SI. Download product specifications and request our latest catalog, a must have reference tool. (read more)

High-quality special purpose screws provide problem solving benefits. SDP/SI adds stainless steel and alloy steel with black oxide or nickel plating captive screws, low profile screws, miniature captive screws and small head diameter screws. Satisfy all your mechanical component requirements at SDP/SI. Download product specifications and request our latest catalog, a must have reference... (read more)

SDP/SI stock planetary gearheads include the high performing, extremely efficient PAC series (S91..(A,T)MPAC) and PAN series (S91..(A,T)MPAN) equipped with a NEMA output flange. For dependable performance, design, mounting, and value shop SDP/SI for gearheads, motors, and motion control products. (read more)

Miniature pillow block mounted ball bearings are ideal in applications with limited space. With an aluminum housing, stainless steel bearing and double shielding, they have excellent corrosion resistance, making them suitable for medical, scientific and pharmaceutical applications. (read more)

Specializing in problem solving components and engineered solutions, SDP/SI manufactures precision gears that offer the best of both worlds: noise reduction benefits of acetal rim gear teeth along with the strength and stability of an aluminum core assembled onto a stainless steel hub. Identified as S1268Z-…M series, get product specifications here. Note the unique Fairloc... (read more)

Constant force extension springs are designed to be used in any application that requires a smooth, even, uniform load through the entire length of travel (deflection) for retracting or extending. (read more)

SDP/SI manufactures metal and nonmetallic pulleys in a variety of profiles, sizes, styles and numbers of teeth. To ensure long life and quiet operation in your application our pulleys are made to the exact timing belt profile. To complete your drive system, get your timing belts from SDP/SI. (read more)

Precision shaft differentials manufactured by SDP/SI, feature built-in anti-backlash characteristics for eliminating play in shaft rotations. Identified as part number S9540A-TS9, the differential provides a high level of precision in instrument drives and is particularly effective at adding and subtracting shaft rotations in servo systems. (read more)

Precision anti-backlash gears manufactured by Stock Drive Products/Sterling Instrument,ISO 9001 + AS9100 certified, feature the exclusive Fairloc® integral hub which allows precise positioning on the shaft. These gears are compact, self-contained and offer a small gear hub envelope. (read more)

Designed for miniature applications the SDP/SI right angle gear drives feature lightweight, non-corrosive, all metal construction. Identified as the A 2Z1A-... series, the standard mount gear drives are made of anodized aluminum housings and hardened steel helical gears. Also offered are base-mounted and panel-mounted miniature right angle helical gear drives with a fiberglass rei... (read more)

Precision gear & dial hubs from SDP/SI are designed to fit gears or dials and eliminate keys or splines. Identified as the S2F06Y-.... series, these 303 stainless steel hubs feature our patented Fairloc® design. The compact self-contained design is perfect when hub O.D. is limited. (read more)

SDP/SI offers a new, low backlash variant on its existing line of multi-plate in-line slip clutches. Both versions feature an all mechanical design, which makes them considerably cheaper than electromechanical alternatives. Identified as the S98CA7-... series, these low backlash clutches are perfect when precision is required and space is limited. (read more)

Anti-backlash gears manufactured by SDP/SI (ISO 9001 + AS9100D Registered) feature an effective way to eliminate backlash in gear trains that include small-diameter gears. Designated as pin-type mini-lash gears, each gear is composed of a set of two gear halves that give the appearance of a split gear. (read more)

Commercial and precision spur gears manufactured by Stock Drive Products/Sterling Instrument are produced to ISO Class 7 specs and stocked in a wide variety of materials including stainless steel, aluminum, aluminum alloy, nylon, acetal, brass and steel. Our spur gears are available in 120, 96, 80, 72, 64, 48, 32, & 24 Pitch with pressure angles of 20° degrees and 14-1/2° deg... (read more)

SDP/SI offers an off-the-shelf series of inch and metric size splined sleeve type flexible couplings that offer torsional resiliency to absorb load pulsations and shocks in instrumentation applications. The couplings can accommodate up to 7 degrees of angular misalignment and transmit up to 1/2 hp at 1750 rpm. (read more)

A new series of inch couplings from SDP/SI feature unique lattice design allows for very large axial, radial, and angular misalignments while transmitting high torque loads with zero backlash. The 34 couplings identified as the S50CLM-... and S50CLP-... inch series, feature a maximum angular offset of 7°. A complete series of 24 metric lattice couplings with similar spe... (read more)

SDP/SI (ISO 9001 + AS9100D Registered) offers several different series of pulleys for 1/5" small pitch timing belts. They offer positive, efficient power transmission for belt drives, with no slip or backlash and minimal vibration. These pulleys are designed to operate with synchronous toothed belts. (read more)

Precision internal gears from Stock Drive Products / Sterling Instrument (ISO 9001 + AS9100D Registered) are available from stock in inch and metric sizes. These 20° pressure angle inch gears are offered in 303 stainless steel or 2024-T4 anodized aluminum. The metric gears in Modules 0.5, 0.8, & 1 are ISO Class 7 and are stocked in 5, 8 & 10 mm face widths. (read more)

Plastic cam followers, identified as the S7NSRY-... series, are designed to transmit motion and carry load in today's high-speed and light-duty machines in medical, packaging, and semi-conductor equipment. These cam followers allow clean operation and will not contaminate product or surroundings with lubricant or metal flakes. (read more)

SDP/SI offers a large selection of precision ground shafting to fit a wide variety of applications. With straightness as low as .0002 inches per inch, they provide highly precise alignment where necessary. Diameters start as low as .0311”, and shaft lengths as low as 1”, so they can be used for miniature applications as well. (read more)

SDP/SI engineers and manufactures precision gears, gearboxes, and motion control components in the USA, delivering custom mechanical solutions for demanding aerospace, defense, medical, and automation applications. (read more)

SDP/SI delivers precision-engineered mechanical components, custom gearboxes, CNC machining, and gear manufacturing for aerospace, medical, industrial, and technology markets. With vertically integrated engineering, prototyping, and production, the company helps improve manufacturability, refine designs, and scale. (read more)

SDP/SI delivers precision-engineered components, gear systems, and electromechanical assemblies for medical applications, combining in-house engineering, advanced CNC manufacturing, and scalable production capabilities to help OEMs accelerate development, improve manufacturability, and achieve reliable, high-quality production outcomes. (read more)