Cut Off Wheels
According to the difference in the material and hardness of the metallographic sample, the correct selection of the grinding wheel cutting blade can improve the cutting efficiency and minimize the damage to the sample.
According to the different materials of metallographic specimens, our company has developed a series of metallographic cutting blades which are specially adapted for metallographic cutting. Various specifications are complete, suitable for metallographic sample cutting machines of various models and specifications at home and abroad. It can fully replace similar products of professional foreign companies.
All cutting discs are made of high-strength resin and preferably special abrasives, which allow a large linear speed, more than 50 m/s, and are not brittle. Sharp cutting, minimal cutting heat, and shallow heat-affected layer of the sample minimize interference and provide the perfect prerequisite for the next step in metallographic sample preparation.
Key Features
Technical Specifications
| Series | Material | Scope of Application | Linear Velocity | Specification |
| A60 | Alumina, resin-based | Extremely hard ferrous metal (HRC>55) | 30~36m/s | 150×12.7×0.5, 200×22×0.8, 250×32×1.5, 300×32×2.0, 350×32×2.5, 400×32×3.0, 450×32×3.2, 508×50.8×4.0 |
| A50 | Alumina, resin-based | Hard ferrous metal (HRC44~55) | 32~40m/s | - |
| A30 | Alumina, resin-based | Softer ferrous metal (HRC20~40) | 35~45m/s | - |
| S20 | Silicon carbide material, resin based | Very soft non-ferrous metals such as copper alloys, aluminum alloys (HV<2000) | 35~45m/s | - |
Instructions
Installation
● Select the appropriate grinding wheel cutting disc according to the material, hardness, etc. of the material to be cut before use.
● Use a flanged with a diameter of not less than 1/4 of the wheel diameter to compress the cut-off wheel. Make sure there is a tight fit between the contact surfaces, screw in the screw, and tighten the screw with the ejector pin and wrench.
Unload
Use the ejector rod and wrench to loosen the screw, then unscrew the screw, remove the flange carefully remove the grinding wheel along the middle seam of the fixture, and store it properly.
Use
● At the beginning of cutting, use a small force to cut in slowly, and after the grinding wheel is cut in, feed it smoothly according to the feel. The feed rate is recommended to be between 0.1~2mm/s. A slower feed rate is recommended for harder and larger cross-section materials, and a higher feed rate for softer and smaller cross-section materials.
● Make sure you have enough cooling water and inject the water directly into the cut. Cooling must be uniform on both sides of the wheel cutting disc.
● In order to obtain the best cooling effect, try to choose a smaller section for cutting.
● If cut correctly, there will be no burn. If the sample is burnt, reduce the feed rate, improve cooling or use a softer grinding wheel to cut the disc. If the wheel wears too much, reduce the feed rate or use a harder wheel cutting disc.
When grinding wheel cutting discs are used correctly, the edge of the wheel will be straight, concave or convex. If the wheel cutting blade is too hard or the cooling water is not adjusted correctly, the wheel edge wears unevenly.
Rotational Speed Parameters
| Hardness | Linear Velocity | φ200 | φ250 | Φ300 | Φ350 | Φ400 |
| HRC>60 | 30~36m/s | 2850~3400 | 2280~2740 | 1900~2250 | 1600~1950 | 1450~1700 |
| HRC40~60 | 32~40m/s | 3050~3800 | 2450~3000 | 2050~2500 | 1750~2170 | 1550~1900 |
| HRC<40 | 35~45m/s | 3350~4280 | 2660~3400 | 2250~2850 | 1900~2450 | 1660~2100 |
Safety Precautions
● Before working, you must wear labor protection equipment and check whether the equipment has a qualified grounding wire.
● To check and confirm whether the grinding wheel cutting machine is intact and whether the grinding wheel piece has deformation, cracks, chipping and other defects, and prohibit the use of diseased equipment and unqualified grinding wheel pieces.
● Grinding wheel is only allowed to be installed and used in one piece, and it is strictly forbidden to install and use two or more pieces at the same time.
● When cutting materials, do not use excessive force or sudden impact, and turn off the power immediately when there is an abnormal situation.
● It is not allowed to install the grinding wheel that has been worn on the cutting machine with a larger specification on a cutting machine with a smaller specification and continue to use it.
● When replacing the grinding wheel, wait for the equipment to stop stably, and check the grinding wheel.
● Note that the maximum speed of the grinding wheel installed should match the cutting machine, and it should not be used at excessive speed.
● To choose a suitable cutting blade according to the cut sample, you can choose according to the products provided above.
● Store resin cut sheets in a place out of direct sunlight and moisture, and in a horizontal position.
● The cutting blade should be installed as required, and the test start operation should be smooth before starting to work.
● The workpiece must be clamped to avoid loosening, otherwise it will cause the vibration of grinding wheel during cutting, and the partial instantaneous force of the grinding wheel will exceed its bearing limit and an explosion accident will occur.
● It is strictly forbidden to sand objects on the cutting blade.
● The clamping device should be safe and reliable to prevent accidents when the workpiece is loose.
● When cutting, the operator should cut evenly and avoid the front of the cutting blade to prevent accidents due to improper operation of the cutting blade.
● After the work is completed, wipe the dust on the surface of the grinding wheel cutting machine and clean the workplace, rain-proof measures should be taken for outdoor storage.
Common Problems and Solutions
| Common Problem | Possible Reason | Corresponding Solution |
| The grinding wheel wears too fast and the life is short | • The selected grinding wheel is not hard enough to cut this material. • The grinding wheel is too thin. • The speed of the cutting machine is too low. • The cutting pressure is too high and the feed speed is too fast. |
• Select the appropriate hardness grinding wheel according to the technical parameter table above. • Choose a relatively thick wheel. • Refer to the technical data table above to select a higher speed. • Reduce cutting pressure, reduce feed speed. |
| Low cutting efficiency | • The hardness of the grinding wheel is not appropriate. • The selected wheel diameter is too small relative to the diameter of the cutting surface. • The power of the cutter is too low. |
• Select the appropriate hardness grinding wheel according to the technical parameter table above. • Choose a wheel with a larger diameter. • Use a more powerful cutter. |
| Grinding wheel stuck | • Improper selection of grinding wheel. | • Select the corresponding grinding wheel according to the technical parameters in the table above. |
| Burns on the edges | • The grinding wheel is too hard. • The cutting feed is too large and the cutting pressure is too high. • Improper cutting method (eg cutting in one place for a long time). • Too little cutting coolant or incorrect spraying. |
• Choose a wheel with a lower hardness. • Reduce the cutting feed and reduce the cutting pressure. • Try to cut back and forth in a straight line as many times as possible, do not cut in one place for too long, exit the stroke properly, and then carry out the cutting operation. • Replenish the cutting coolant and adjust the coolant nozzle to the right position. |
| Lots of burrs after cutting | • Grinding wheel piece is too thick. • The particle size of the wheel is too coarse. |
• Choose a thinner wheel. • Choose a grinding wheel with a finer particle size. |
| Uneven wear on the edge of the wheel | • Improper way of working (use the cutting discs as grinding discs). • The workpiece is not clamped firmly, resulting in vibration. |
• It is strictly forbidden to use the cutting disc as a grinding disc. Please use a special grinding disc or a multi-purpose grinding wheel. • The workpiece must be securely clamped in a suitable position for cutting or grinding. |
| Broken grinding wheel | • Wheel stuck during cutting. • Incorrect cutting, such as cutting with too much force, grinding wheel piece being used at excessive speed, cutting too fast at the beginning, or cutting multiple pieces of material at the same time. • The structure of the cutting blade is uneven, the flatness of the cutting blade is poor, the hardness of the cutting blade is high, and the resin of the cutting blade lacks toughness. • The diameter of the flange is less than 1/4 of the diameter of the grinding wheel. • Poor lubrication, dry cut. |
• Vertical cutting must be ensured, otherwise there will be excessive lateral pressure on one side, resulting in the rupture of the cutting blade. • Reduce the cutting force appropriately, use it according to the speed limit, put it slowly and gently at the beginning of cutting, and cut only one piece of material at a time. • Replace it with the qualified grinding wheel. • Replace the flange with a diameter larger than 1/4 of the diameter of the grinding wheel. • Add or replace the cutting coolant. |
| Vibration of grinding wheel | • The balance of the grinding wheel is not good. • Improper maintenance of the cutter (e.g. excessive bearing wear) • Improper wheel clamping, resulting in the wheel not being installed in the center. |
• Please replace the grinding wheel. • Replace the bearings. • Check the bearing of the cutting machine, and check the operation after the grinding wheel is clamped. |
| Bias Cutting of workpiece | • The flatness of the grinding wheel exceeds the standard, and there is deflection when rotating. • Uneven texture of the grinding wheel. • Unequal grinding force on both sides of the grinding wheel. |
• Replace the grinding wheel with qualified flatness. • Replace the cutting blade with a uniform texture. • Use a grinding wheel with the same texture on both sides, and spray the cutting coolant evenly on both sides of the grinding wheel. |
Storage Method
Lay the grinding wheel flat or hang it in a ventilated and cool place, avoid direct sunlight and avoid humid environment. The stacking of grinding wheels should not be too high.
Application Fields
Cut Off Wheels are ideal for:
• Ferrous Metals: Extremely hard ferrous metals (HRC>55), hard ferrous metals (HRC44~55), softer ferrous metals (HRC20~40)
• Non-Ferrous Metals: Copper alloys, aluminum alloys, other soft non-ferrous metals (HV<2000)
• Metallographic Sample Preparation: Sample cutting for metallographic analysis
• Industrial Applications: Various industrial cutting applications