Precision Power Resistors

Wire wound components engineered for applications requiring dependable resistance values under load. Available in 2-terminal and 4-terminal Kelvin configurations with precision tolerances, low TCR, and heavy-duty power handling.

Engineered for Demanding Applications

Serving voltage drop, power conditioning, signal attenuation, and general precision resistance applications across defense, aerospace, industrial, medical, and telecom markets.

Precision Tolerances

Standard tolerances from ±1% down to ±0.005% for ultra-precise current measurement applications.

Low TCR Performance

Temperature coefficient of resistance as low as 0±10 ppm/°C, ensuring stable operation across temperature ranges.

Heavy-Duty Power

Power ratings from 0.01W for signal-level circuits up to 25W+ for demanding power applications.

Built to Last

Stability of ±0.001%/year at +25°C with no load. Artificially aged wire for long-term reliability.

Three Series, One Standard of Excellence

Each series is optimized for specific application requirements while maintaining PRC’s commitment to precision and reliability.

The SM series is PRC’s broadest line of 2-terminal axial lead precision power resistors. These epoxy-encapsulated wire wound resistors are available in a wide range of physical sizes and power ratings, from sub-watt designs suitable for signal-level circuits up to 25W+ configurations for power applications. Resistance values span from 0.02Ω to 4MΩ with standard tolerances of ±1% (tighter tolerances to ±0.1% available

Standard TCR is 0±10 ppm/°C for values of 100Ω and above, and 0±15 ppm/°C for values below 100Ω. All SM series parts use hot-tinned commercially pure copper terminals and are calibrated at +25°C. Production specs transfer quickly from the lab to the production floor, making the SM series a strong choice for both prototype development and volume production runs.

Individual SM series model numbers (e.g., SM094, SM155, SM186, SM1711) designate specific physical dimensions, power ratings, and lead configurations. Contact PRC engineering for help selecting the optimal package for your application requirements.

The SM-4 series provides 4-terminal Kelvin connections for precision current measurement and applications where lead resistance must be eliminated from the measurement. With resistance values from 0.015Ω to 100Ω and tolerances to ±0.005%, the SM-4 is designed for accurate voltage drop measurements under load. The 4-terminal configuration allows separate current-carrying and voltage-sensing connections, ensuring that the measured voltage drop is across the resistance element only.

SM-4 parts are rated for an extended temperature range of -65°C to +275°C at ±1% tolerance, with derating required for closer tolerances and lower resistance values. Stability is ±0.001%/year at +25°C with no load. Like all PRC products, the SM-4 uses pure copper terminals with low EMF construction.

The SX series offers high-precision performance in a silicone-coated package. Silicone coating provides superior environmental protection and flexibility compared to standard epoxy encapsulation, making SX parts suitable for applications subject to thermal cycling or mechanical stress. Available in three power tiers (0.01–0.1W, 0.11–0.5W, and 0.51W+), the SX series covers resistance values from 0.01Ω to 6MΩ with standard tolerances to ±0.05%.

For applications requiring tighter tolerances than the SX series offers, the ultra-precision HR series (detailed on the Ultra-Precision Resistors page) provides tolerances to ±0.005% with TCRs to 0±1 ppm/°C.

2-Terminal Precision Power Resistors

PRC’s broadest line of 2-terminal axial lead precision power resistors. Epoxy-encapsulated wire wound resistors available in a wide range of physical sizes and power ratings.

Resistance

0.02Ω to 4MΩ

Tolerance

±1% to ±0.1%

TCR

0±10 ppm/°C (≥100Ω)

Power

0.5W to 25W+

Temp Range

-55°C to +145°C

Construction

Epoxy encapsulated

Standard TCR is 0±15 ppm/°C for values below 100Ω. All parts use hot-tinned commercially pure copper terminals and are calibrated at +25°C.

4-Terminal (Kelvin) Precision Resistors

4-terminal Kelvin connections for precision current measurement. Separate current-carrying and voltage-sensing connections ensure measured voltage drop is across the resistance element only.

Resistance

0.015Ω to 100Ω

Tolerance

±1% to ±0.005%

TCR

0±15 ppm/°C

Power

0.75W to 25W+

Temp Range

-65°C to +275°C

Construction

Epoxy encapsulated

Stability is ±0.001%/year at +25°C with no load. Low EMF construction with pure copper terminals. Extended temp range for demanding environments.

Silicone Coated High-Precision Resistors

High-precision performance in a silicone-coated package. Superior environmental protection and flexibility for applications subject to thermal cycling or mechanical stress.

Resistance

0.01Ω to 6MΩ

Tolerance

±1% to ±0.05%

TCR

0±10 ppm/°C (≥100Ω)

Power

0.5W to 25W+

Temp Range

-55°C to +145°C

Construction

Silicone coated

Available in three power tiers: Low (0.01–0.1W), Mid (0.11– 0.5W), and High (0.51W+). For tighter tolerances, see the ultra-precision HR series.

Series Comparison

Compare key specifications across all precision power resistor series to find the right fit for your application.

Common Specifications

Every PRC precision power resistor shares these foundational quality standards, regardless of series.

Terminals

Hot-tinned, oxygen-free, high-conductivity (OFHC) commercially pure copper

Low EMF

<0.3 to 1.5 μV/°C with respect to copper terminals

Stability

±0.001%/year at +25°C, no load (series dependent)

Calibration

100% tested at +25°C to specified limits

Compliance

RoHS and REACH directive compliant

Custom Manufacturing

Any ohmic value, tolerance, wattage, and physical size to your specifications

Derating

Required for temperatures above +25°C and for closer tolerances (refer to individual series derating curves)

Packaging

Bulk or tape-and-reel available

Trusted Across Industries

PRC precision power resistors serve critical applications where failure is not an option.

Mission-critical resistance solutions for military electronics and weapons systems

High-reliability components for avionics, satellite systems, and space applications

Rugged power resistors for process control, power supplies, and motor drives

Precision components for diagnostic equipment and patient monitoring systems

Stable resistance values for signal conditioning and communications infrastructure

Ultra-precise resistors for calibration standards and measurement instrumentation

Need Help Selecting a Part?

Contact our engineering team or submit a Request for Quote with your specifications. Engineering samples are available at no cost within 7-10 business days for most configurations.

Precision Power Resistors