5 X 8 X 14 mm Electric Tool Carbon Brush Set With Auto Stop Replace Parts

5×8×14 mm Electric Tool Carbon Brush Set With Auto Stop Replace Parts

Key Information Analysis:

1. Product Attribute: Small Electric Tool Carbon Brush Set with Auto-Stop Function (as Replace Parts)
   Made by pressing a mixture of high-purity graphite and a small amount of copper powder (copper content approximately 15%-25%), with a built-in auto-stop trigger structure, it has three core characteristics:
   • Automatic protection mechanism: The carbon brush features a built-in wear induction design. When worn down to the critical length (about 4.7mm, i.e., 1/3 of the original length), it will trigger a circuit disconnection or mechanical locking, forcing the motor to stop running. This prevents motor burnout caused by direct friction between the metal base and the commutator after the carbon brush is completely worn out, making it especially suitable for beginners or high-frequency use scenarios;
   • Miniaturized adaptation: The slender cross-sectional size of 5×8mm is specially designed for ultra-small brush holders, adapting to micro motors with power ranging from 100-400W (such as precision electric drills and small sanders). The 14mm length balances wear allowance and installation space, with a service life of about 500-1000 hours;
   • Set integrity: Includes 2 carbon brushes and matching springs (some include mounting clips), ensuring synchronous replacement of both sides, maintaining current balance, and reducing abnormal sparks or power fluctuations caused by uneven wear on one side.
2. Compatibility Range:
   Based on the 5×8×14mm specification and auto-stop function, it is mainly compatible with the following equipment:
   • Precision small tools: Such as mini electric drills, jade carving machines, small edge trimmers, and nail grinders;
   • Household equipment: Motors of some models of handheld vacuum cleaners, small mixers, electric hair clippers, etc. (power 100-400W).
     The core of compatibility lies in the dual matching of size and auto-stop mechanism – the 5×8mm cross-section must fit perfectly with the brush holder (with an error of ≤0.1mm), and it is also necessary to confirm that the motor circuit supports the shutdown function triggered by the carbon brush to avoid protection failure due to compatibility issues.
3. Size Specifications: 5×8×14mm
   This size belongs to the category of ultra-small carbon brushes. The 5mm thickness and 8mm width fit narrow carbon brush mounting slots, and the 14mm length includes a reserved trigger section of about 3mm (used to activate the auto-stop function). The dimensional accuracy is controlled within ±0.1mm to ensure uniform contact with the commutator and guarantee the triggering accuracy of the auto-stop mechanism.
4. Functions and Roles:
   • Basic conduction function: Through sliding contact between graphite and the commutator, it stably transmits current to the rotor, ensuring power output of small tools during fine operations (such as jewelry polishing and circuit board drilling);
   • Automatic protection function: When the carbon brush is worn down to the safety threshold, the built-in structure cuts off the current or jams the rotor, forcing the tool to stop, fundamentally avoiding motor overload or mechanical damage and reducing maintenance costs.
5. Replacement and Usage Tips:
   • When the tool suddenly stops automatically (non-fault power outage) and the carbon brush length is worn down to less than 4.7mm, the set must be replaced immediately;
   • During installation, ensure the spring is reset correctly to avoid poor contact or false triggering of the auto-stop function due to insufficient pressure;
   • After replacement, it is recommended to run the tool under no load for 30 seconds to check for abnormal sparks or noise, and confirm the installation is correct before putting it into use.