How to Sharpen Shear Blades

How to Sharpen Shear Blades?

Hydraulic shearing machine is an important tool in the manufacturing and metalworking industries. Hydraulic shear uses hydraulic power to drive the shearing blades to complete various shearing tasks. Sharpening shear blades is an important maintenance task to ensure they continue to provide clean, precise cuts.

Understanding the key components of hydraulic shear machines, such as blades, and maintaining them appropriately can ensure that these machines remain reliable and efficient in modern production environments.

 

Type of industrial shear blade sharpening material

Carbon tool steel blades are known for their cost-effectiveness and are best suited for light to moderate cutting tasks. These blades are made of rich carbon steel such as T10, T8, and 65, and undergo heat treatment to improve durability, making them a common choice in industries such as automotive and construction.

Low alloy tool steel blades contain elements such as chromium, silicon, and tungsten, designed specifically for higher demand applications. Compared to carbon steel, they have stronger blade retention, wear resistance, and toughness.
9CrSi, 6CrW2Si, and Cr12MoV grades can improve cutting efficiency, and handle harder materials such as hot-rolled steel plates, stainless steel, and medium thick steel plates with higher tensile strength. Industries such as heavy machinery manufacturing and metal processing prefer low alloy shear blades because they can withstand long-term operation without frequent replacement.
Low alloy tool steel is particularly suitable for applications that require stable cutting performance at medium to high strength, such as processing thicker plates or harder metals.

High alloy tool steel blades are suitable for harsh environments that require high stress, high temperature, and high cutting force. For example, alloys such as 4Cr5MoSiV1 (H13) and W6Mo5Cr4V2 contain chromium, molybdenum, vanadium, and tungsten. The characteristics of this material are high temperature resistance and resistance to annealing.

 

How to Sharpen Shear Blades?

Sharpening shear blades involves a few straightforward steps to restore their cutting efficiency. It is a specialized process that requires care, accuracy, and the right tools. Here’s a step-by-step guide on how to sharpen shear blades:

1. Remove the Shear Blades from the Machine:
Before sharpening shear blades, make sure the machine is turned off and has cooled down . Use the wrenches to remove the shear blades from the machine. Keep track of the blade’s orientation for reinstallation.

2. Clean the Blades:
Before sharpening machine blades, thoroughly clean the blades to remove any metal shavings. Use a brush or solvent to clean the surfaces. Clean blades will help you avoid contamination during the sharpening process.
3. Inspect the Blade for Damage:
Check the blades for any nicks, cracks, or excessive wear. If there are significant defects, it may be better to replace the blades rather than sharpen shear blades.
4. Set the Correct Angle:
Shear blades typically have a specific cutting angle, which is important for achieving sharpness and precision. Common angles for shear blades range from 30° to 45°, depending on the type of shear. Use an angle gauge or protractor to set the correct angle on the grinding wheel. and make sure that the angle is consistent across the entire cutting edge process.
5. Sharpen shear Blades:
Using a Bench Grinder: If you’re using a bench grinder, carefully position the blade against the grinding wheel. Hold the blade firmly and move it back and forth across the wheel to remove material evenly from the edge. Keep the blade cool to avoid overheating, which can reduce its hardness. Use water or a cooling system if available to prevent heat buildup.
Using a Surface Grinder: If you’re using a surface grinder, place the blade on the bed and set the machine to the correct angle. The surface grinder will offer more control and precision compared to a bench grinder. Move the blade slowly across the grinding wheel to achieve an even, sharp edge.

Grinding Technology:

Avoid Overheating: Do not apply excessive pressure or overheat the blade. High temperatures can alter the metal’s properties, making the blade brittle.
Keep the Blade Even: Ensure the blade edge remains even and consistent across the entire length. Uneven sharpening can lead to poor cutting performance.
6. Check the Blade Flatness:
After shear blade sharpening, check the flatness of the blade using a dial indicator or a straight edge. The cutting edge should be straight and free of any warps or bends. If the blade is not flat, it can cause uneven cuts.
If necessary, use the grinding machine to lightly touch up any areas that are not perfectly flat.
7. Deburr the Edges:
After sharpening, use a fine abrasive stone to remove any burrs along the cutting surface. Burrs can affect the performance of the shearing machine and damage the material being cut.
8. Reinstall the Blades:
Once the blades are sharpened and deburred, carefully reinstall them onto the shearing machine. Ensure they are properly aligned and securely fastened. Follow the manufacturer’s instructions for blade installation and torque specifications.
9. Test the Shear Blades:
After installation, run a test cut to check the sharpness and performance of the metal shear blades. Ensure the cuts are clean and smooth. If the cuts are rough or uneven, the blades may need further adjustment or sharpening.

Additional Tips:
Grinding Wheel Selection: Choose the right grinding wheel based on the material of the shear blades. For high-speed steel (HSS) or other hard metals, a diamond grinding wheel or a silicon carbide wheel is best.

Consistency: Regularly inspect and sharpen shear blades to maintain optimal cutting performance. Prolonged use without sharpening can result in excessive wear and poor cutting quality.

Sharpening Frequency: The frequency of sharpening depends on the amount of use the shear blades get. For high-volume operations, blades may need sharpening more frequently, while for lighter use, it could be done less often.

Sharpening shear blades is a delicate process that requires attention to detail and the right tools. Properly maintaining and sharpening shear blades will ensure the longevity and efficiency of your shearing machine, allowing for cleaner cuts and reduced operational costs.