Motor Carbon Brush 7mm X 11mm X 12/13mm for Electric Tools Repair Parts

Motor Carbon Brush 7mm × 11mm × 12/13mm for Electric Tools Repair Parts

Key Information Analysis:

1. Product Attribute: Motor Carbon Brush for Electric Tool Repair (as Repair Parts)
   Made by pressing a mixture of high-purity graphite and an appropriate amount of copper powder (copper content approximately 20%-30%), it has two core characteristics:
   • Miniaturized adaptability: The compact cross-sectional size (7×11mm) is specially designed for small motors with limited space, fitting the brush holder structure of most light electric tools;
   • Dual-length compatibility: The same cross-sectional size is paired with two lengths (12mm and 13mm), and the small 1mm length difference can cover installation requirements caused by design details differences in tools of different brands or models, improving the versatility of repair parts.
2. Compatibility Range:
   Based on the 7×11×12/13mm specification, it is suitable for brushed motors of various small electric tools. Common compatible equipment includes:
   • Light electric tools: such as micro electric drills, handheld sanders, small polishers, electric screwdrivers, etc. (power 200-600W);
   • Portable devices: some models of jigsaws, edge trimmers, electric scissors, etc.
     The core of compatibility is that the cross-sectional size (7×11mm) must completely match the brush holder (with an error of ≤0.2mm). The two length specifications correspond to the carbon brush installation depths of different devices respectively, and must strictly match the length of the original carbon brush to avoid jamming due to excessive length or poor contact due to insufficient length.
3. Size Specifications: 7mm × 11mm × 12/13mm
   This size belongs to the category of small carbon brushes. The 7mm thickness and 11mm width fit most compact-structured brush holders. The 12mm and 13mm length designs balance wear allowance and installation space constraints – 12mm is suitable for ultra-small motors, while 13mm provides more wear buffer for slightly larger devices (service life is about 600-1200 hours). The dimensional accuracy is controlled within ±0.1mm to ensure uniform contact with the commutator, reducing sparks and noise during operation.
4. Functions and Roles:
   • Serves as the "current conduction medium" for small motors, stably transmitting external current to the rotor through sliding contact with the commutator, ensuring stable power output of light electric tools during fine operations (such as small drilling, grinding, and screw tightening);
   • The self-lubricating property of graphite can reduce wear on the commutator, extend the service life of small motors, and reduce maintenance frequency.
5. Replacement Tips:
   The carbon brush should be replaced in time when the electric tool shows the following conditions:
   • The carbon brush is worn down to less than 1/3 of its original length (about 4mm for the 12mm specification and about 4.3mm for the 13mm specification);
   • There are significantly more sparks at the carbon brush during motor operation, accompanied by a continuous "sizzling" friction sound;
   • The output power of the tool decreases, such as reduced rotational speed, insufficient power, or even difficulty in starting.