Do you have any questions about use of the angle grinder? I'll help you.

When operating an angle grinder, safety is always the top priority. Here are the key points that must be noted, which are easier to understand when combined with actual scenarios: 
1. Put on complete protective equipment
- Must wear goggles (to prevent splashing debris, such as sparks and dust that may fly into the eyes during metal cutting), dust masks (when grinding stone or concrete, there is a lot of dust, and long-term inhalation can damage the lungs), anti-slip gloves (to prevent the machine from slipping and falling off, especially when operating with one hand), long-sleeved work clothes and anti-slip shoes (to avoid skin scratches from debris and clothing burns from sparks).
- Long hair should be tied up and a work cap should be worn to avoid being caught in the machine; wearing necklaces, gloves with fringes, etc. that are prone to entanglement is prohibited.
2. Check the machine and accessories before starting
- Confirm that the grinding wheel/blade is in good condition (no cracks or deformations), the model is matched (for example, a resin grinding wheel is used for metal cutting, and a fiber wheel for grinding; mixing them can cause the wheel to crack), and is installed firmly (the nuts should be neither too loose nor too tight; if too loose, the blade may fly off; if too tight, it may crush the grinding wheel).
- Before starting, idle the machine for 3-5 seconds to listen for normal sounds (no abnormal noises, excessive vibration); observe whether the grinding wheel is eccentrically shaking; if there are any problems, stop the machine immediately for inspection.
3. Operating posture and environmental norms
- Stand firmly with both feet shoulder-width apart, with the body sideways to the working direction (to avoid facing the grinding wheel directly; in case the fragments fly out, it can reduce direct injury); use natural arm force; do not bend over or stretch excessively (to prevent imbalance).
- The working area should be clean; remove flammable materials around (such as sparks from metal cutting may ignite wood chips and paint); maintain ventilation (especially when grinding generates dust); do not operate on slippery or oily ground to prevent slipping.
4. Correct usage and avoiding non-compliant operations
- Do not operate with one hand! Both hands must firmly hold the handles (one hand holds the front grip, the other holds the rear switch); to prevent the reaction force from causing the machine to lose control (for example, when grinding, the grinding wheel may suddenly get stuck, and the counterforce may cause the machine to swing).
- During cutting/grinding, the grinding wheel should be in stable contact with the workpiece; avoid applying excessive force to "press the wheel" (which may cause the wheel to overheat and crack); do not suddenly impact the workpiece (for example, using a cutting wheel to pry something; the instantaneous impact force may cause the blade to crack).
- Operating points for different materials: when cutting metal, move slowly to avoid sparks flying onto oneself or others; when grinding stone, follow the grain to prevent the grinding wheel from getting stuck.
5. Shutdown and subsequent handling
- After the work is completed, first turn off the switch, wait until the grinding wheel is completely stopped before lowering the machine (prohibit placing or touching the grinding wheel while the machine is rotating).
- Regularly check if the power cord is damaged, if the switch is sensitive, if there is abnormal noise from the bearings, and if any problems are found, immediately stop using and repair, do not "operate with a faulty machine". 
Remember, the high-speed rotating parts (the grinding wheel) of the angle grinder, if operated improperly, may cause debris to fly and the machine to lose control, resulting in serious injuries. By strictly following the above precautions, you can ensure safe operation.