The molding process, bonding strength, and structural characteristics of different manufacturing processes directly determine the safety risk level. This also provides a basis for routine inspections. Below are three common manufacturing processes.
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Process |
Sintering |
Laser Welding |
Brazing |
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Manufacturing Principle |
Metal powder and diamond are fused together at high temperature, which is a one-time molding process. |
The metal powder is first sintered into rings or serrations, and then laser-welded to the main body, which is a secondary forming process. |
The body is first coated with a layer of metal solder, then coated with a layer of diamond, and then fused at high temperature. This process involves secondary processing and one-time molding. |
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Advantages |
Low cost, simple and mature technology |
High bonding strength, abrasive does not detach, extremely high temperature resistance and safety. |
Extremely high bonding strength, extremely low abrasive shedding rate, excellent heat dissipation, and suitable for ultra-thin slicing. |
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Shortcomings |
Low overall strength, abrasive particles easily detach, poor heat dissipation. |
High cost and high requirements for body thickness |
Extremely expensive and with the most complex process |
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Scope of Application |
Ordinary carbon steel |
Stainless steel, alloy steel |
cemented carbide |
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Conclusion |
Economical products with limited performance are gradually being phased out by high-end technologies. |
High-end metal cutting discs are the mainstream, achieving a perfect balance between safety and performance. |
Manufactured to the highest standards, with unparalleled performance, but at a high price. |
Understanding the operating principles of a cutting machine and the composition of its cutting discs is fundamental to selecting the right blades and mitigating safety risks.
The cutting disc cuts the essence
The cutting wheel uses high-speed moving hard abrasive grains to "micro-peel" the surface of the workpiece-countless tiny material detachments accumulate to ultimately cut and shape the workpiece.
Characteristics of the cutting disc composition
Both abrasive wheel cutting wheels and alloy cutting wheels are composed of "fine abrasive grains + binder + body," making it impossible to manufacture a monolithic structure (due to technological limitations). A monolithic structure offers the optimal safety performance; therefore, non-monolithic cutting wheels are considered "high-risk components" in handheld machinery, requiring enhanced daily management and hazard identification.
Routine inspections should ideally have quantifiable results, as this effectively demonstrates diligence and responsibility.
The breakage and fragmentation of the cutting disc are major safety hazards. A rigorous four-step inspection process-"listen, look, measure, and manage"-is employed, with the specific procedures as follows:
1. Listen: Tapping to determine the internal condition
• Operating Instructions: Gently tap the edge (non-abrasive surface) of the cutting disc with a non-metallic rod (such as a screwdriver handle or plastic rod).
• Judgment Criteria:
• A clear, metallic sound: No internal cracks, in good condition, and ready for normal use.
• A dull, hoarse sound: Hidden cracks exist (difficult to detect with the naked eye), requiring immediate disposal and prohibiting use (cracks can cause the disc to shatter during high-speed rotation).
2. Observe: Check the cutting fit
• Core checkpoint: Does the "saw jamming" phenomenon occur (the saw blade gets stuck on the workpiece during cutting, causing a sudden increase in feed resistance)?
• Cause of the problem: Saw jamming is usually caused by "mismatch between the cutting wheel and the workpiece" (e.g., using a sintered blade to cut cemented carbide, or using an ultra-thin brazed blade to cut thick carbon steel).
• Solution: Immediately stop using the blade and replace it with a cutting disc that matches the material.
3. Measurement: Key Dimensions and Angle Inspection
• Tooth Thickness: Measure the abrasive layer thickness with calipers. If it is less than 1mm, the saw blade must be scrapped (too thin a blade will result in insufficient strength and easy breakage).
• Rake Angle: Measure the rake angle of the saw blade (the angle between the abrasive surface and the feed direction) with an angle gauge. It must be maintained between 15° and 20°. If the angle deviates (e.g., less than 10° or greater than 25°), it will significantly increase the risk of "tooth breakage," requiring repair or scrapping.
4. Tube: Storage and Handling
• Storage Requirements: Cutting discs must be stored separately (avoid stacking with other tools), and heavy objects must not be placed on them (to prevent cracking under pressure).
• Additional Notes: The storage environment must be dry (humidity will cause the metal body to rust, affecting the bond strength), and kept away from high-temperature sources (to prevent the bond agent from softening).
