Precision Brakes and Clutches for the Design Engineer
SDP/SI offers a comprehensive selection of high-performance brakes and clutches to meet the demands of a wide range of rotary motion applications. Our product lineup includes spring-wrapped clutches and brakes, mechanical slip clutches, reverse-acting brakes, zero-backlash clutch couplings, and advanced electromagnetic solutions. These components are essential for controlling torque, speed, and directional motion in both industrial and commercial drive systems. Whether you're looking for a single standard component or require modifications for a custom application, our engineering team is ready to assist—from product selection to full system integration.
Brakes and clutches function by disengaging, stopping, or regulating rotational movement and are classified by their method of engagement, including mechanical, friction-based, and electromagnetic designs. Brakes reduce or halt motion, while clutches disengage the drive shaft to pause rotation and transfer torque to an output shaft. For compact applications, clutch-brake combinations offer both functions in a single unit. SDP/SI’s catalog includes multiple variations such as power-on and power-off brakes, magnetic particle brakes, permanent magnetic brakes, roller and slip clutches, and electromagnetic clutch couplings—making it easy to find the right solution for your torque transmission needs.
Electromagnetic Shaft-Mounted Clutch Couplings
Available In:
Voltage: 24 V dcStatic Torque: 5 - 80 lb-in.
Bore Size: 0.25 in. - 0.50 in.
Electromagnetic Shaft-Mounted Clutch Couplings from SDP/SI are engineered for inline load applications requiring precise torque transmission and control. Operating on a standard 24V DC input, these compact clutch couplings offer fast, reliable engagement and disengagement of rotational power. Custom voltage options and dissimilar bore combinations are available by special order to accommodate specific design requirements. Frequently used in motion control systems, these clutch couplings are ideal for applications involving servo and stepper motors, providing the ability to decelerate or stop motion quickly—often in emergency stop scenarios. When paired with power-off electromagnetic brakes, they are highly effective at holding unbalanced or vertical loads in place, such as those in vertically mounted lead screw assemblies. SDP/SI offers both spring-set and permanent magnet-style power-off brakes, ensuring dependable performance when power is removed.
Slip Clutches
Available In:
Materials: Aluminum, Brass, SteelBore Size: 0.1248 in. (3mm) - 0.8750 in. (16mm)
Outer Diameter: 0.50 in. (12.7mm) - 3.00 in. (76.2mm)
Slip clutches are designed to precisely control torque transfer between rotating components, preventing damage from overload and enhancing motion control in mechanical systems. SDP/SI offers a comprehensive range of mechanical slip clutches to suit a variety of applications, with both inch and metric options available as standard catalog items. Our slip clutches are offered in multiple configurations and sizes, providing flexibility in torque settings, coupling arrangements, and design layouts. Whether you require torque limitation, overload protection, or tension control, our broad selection ensures the right solution is within reach. For assistance with selecting the ideal slip clutch for your application, our engineering team is available to provide expert support.
SDP/SI’s lineup includes several types of slip clutches to meet diverse design requirements. Spring-wrapped and spring-wrapped mechanical clutches offer compact, cost-effective solutions for low to moderate torque control. Standard mechanical and precision mechanical slip clutches provide consistent and reliable torque performance for general and high-accuracy needs, respectively. Inline mechanical and multi-plate Slip-Ease clutches are ideal for applications requiring inline shaft configurations and higher torque capacities. For dynamic torque control and automation systems, magnetic particle and magnetic particle with shaft options provide smooth torque transfer and high responsiveness. With this wide variety, SDP/SI ensures that every motion control challenge can be met with a dependable, well-matched slip clutch solution.
Permanent Magnetic Brakes
Available In:
Torque Range: 0.003 in.lbf in.(0.0003 N.m) - 25.000 lbf in.(7.9 N.m)Our Permanent Magnetic Brakes offer reliable power-off braking with smooth, constant torque and zero slip at preset torque levels—ideal for applications requiring consistent performance and overload protection. Unlike traditional friction-based systems, these brakes require no external power, making them unaffected by power interruptions and highly dependable in critical operations. With no contacting friction elements and only ball bearings as moving parts, they ensure a long service life with zero maintenance. Torque remains stable and independent of speed, allowing for smooth operation at both low and high RPMs. Available in brake (with shaft) and clutch (with hollow shaft) configurations, these units are well-suited for harsh environments and are customizable to meet specific application needs.
Unidirectional Roller Clutches
Available In:
Bore Size: 0.125 in. (4mm) - 0.750 in. (35mm)Outer Diameter: 0.28125 in. (8mm)- 1.00000 in. (42mm)
Width: 0.250 in. (6mm) - 1.000 in. (30mm)
SDP/SI's Unidirectional Roller Clutches are compact, lightweight components engineered to provide reliable torque transmission in one direction while allowing free rotation in the opposite direction. Ideal for indexing, backstopping, and overrunning applications, these clutches are designed for use with hardened shafts ranging from 1/8 inch to 3/4 inch (4 mm to 35 mm). Their low profile and minimal backlash make them well-suited for tight spaces and precise motion control. For added durability and support, models with sintered bronze bearings are available for 3/8 inch to 5/8 inch shafts, while metric versions with needle bearing support are offered for 8 mm to 35 mm shafts. These roller clutches deliver smooth, dependable performance in demanding mechanical systems.
Magnetic Particle Brakes
Available In:
Voltage: 24 V dcTorque Range: 0.06 - 115 lbf in.
Length: 2.10 - 5.53 in.
Magnetic Particle Brakes provide precise, reliable torque control for high-cycle and tensioning applications, making them ideal for use in labeling machines and other systems requiring consistent stopping and positioning. These brakes feature zero backlash, low inertia, and no friction surfaces, resulting in smooth, repeatable performance with minimal wear. Operating on a standard 24V DC input, they offer a broad, finely adjustable torque range that is directly proportional to the DC input current. Common uses include tension control, controlled stops, locking, positioning, and motor testing. SDP/SI's Magnetic particle brakes engage by electrically coupling the shaft to the housing, delivering dependable torque without mechanical contact. All models can be specially ordered with a shaft on one end, and alternative voltage options are also available to meet specific design requirements.
Flange Mounted Power-On Brakes
Available In:
Voltage: 24 V dcStatic Torque: 5 lb-in. (0.565 N•m) - 80 lb-in. (9.039 N•m)
Bore Size: 0.25 in. (6mm) - 5.00 in. (12mm)
SDP/SI’s Flange Mounted Power-On Brakes provide efficient and precise stopping power with zero drag when de-energized and anti-backlash performance when energized, making them ideal for applications requiring smooth starts and accurate stopping. Designed for easy integration, these brakes are available in both inch and metric sizes to suit a variety of system requirements. Operating on a standard 24V DC input, they can also be customized for other voltage specifications upon request. With their compact flange-mounted design and dependable performance, these brakes are a reliable choice for motion control systems where clean disengagement and accurate torque holding are essential.
Power-Off Servo Brakes
Available In:
Voltage: 24 V dcStatic Torque: 5 lbin. (0.56 N•m) - 80 lbin. (9.04 N•m)
Length: 1.18 in. (30mm) - 1.45 in. (41.9mm)
Power-Off Servo Brakes from SDP/SI are designed to automatically engage and hold a load when electrical power is lost, ensuring safety and control in critical motion applications. Commonly mounted near electric motors, these brakes are offered in both inch and metric sizes and come in various configurations to suit diverse system requirements. Featuring a splined hub, they are energy efficient, economical, and designed for simple installation. Operating on standard 24V DC, other voltage options are available by special order. For applications requiring compact and reliable holding torque, power-off parallel plate brakes are also available, making these servo brakes a versatile choice for secure, fail-safe braking.