Unique-Bargains 120 Ohm 25W Aluminium Chassis Mount Wirewound Resistors Green 5pcs

120 Ohm 25W Chassis Resistors

This pack contains five aluminium-housed wirewound resistors rated at 120 ohms with a 5% tolerance and a 25W power rating. They are designed for chassis mounting using screws and suit applications such as power supplies, transducers and industrial equipment where reliable heat dissipation is required. The green anodised aluminium casing provides mechanical strength and thermal transfer to a mounting surface. Buyers needing surface-mount components or lower power ratings should look elsewhere.

Chassis-Mount Thermal Limits

Each resistor measures 27 x 16 x 15.5 mm with a total length of 53 mm including terminals, and the mounting hole diameter is 3.5 mm. The aluminium housing is intended for direct attachment to a cooling plate or metal chassis; without adequate thermal coupling the 25W rating cannot be sustained. The wirewound construction offers good vibration resistance but introduces inductance that may affect high-frequency circuits. Designs requiring non-inductive loads or forced-air cooling without a solid mounting surface will not meet the rated performance.

120 Ohm 5% Tolerance Value

The critical specification is the 120 ohm resistance with a +/- 5% (J) tolerance at the full 25W rating. This value determines whether the component matches the circuit design for current limiting, braking or voltage division tasks. The pack supplies five identical units weighing 67 g total, allowing spares for prototyping or maintenance. Engineers specifying a different resistance, tighter tolerance or higher power density must select a different part.