Slitting knives, also known as slitter blades, circular slitting blades, or slitting machine knives, are key cutting components installed on slitting machines and coil slitting lines. They are mainly used for longitudinal slitting and cutting of metal coils, strip steel, and sheet materials.
Slitting Knives Selection Guide
Selection Based on Material Properties
1. Thin sheets and soft materials
Suitable for 0.3–3.2 mm cold-rolled steel, copper, and soft aluminum. It is recommended to use SKD11 (Cr12MoV) or similar tough materials with smaller clearance settings to reduce burr formation and blade chipping.
2. Medium and heavy materials
Suitable for 3.2–9.0 mm stainless steel, hot-rolled steel, and high-strength steel. High hardness materials such as SKH51, SKH54, or ACD8 are recommended to ensure better wear resistance and impact resistance.
3. Ultra-thin materials
Suitable for 0.1–0.5 mm silicon steel and other precision strips. High-hardness knives with strictly controlled clearance are required to ensure cutting accuracy and stability.
Machine Compatibility
1. Outer diameter matching
The blade outer diameter must match the machine’s cutting depth, typically more than 40 times the sheet thickness, to avoid incomplete cutting or blade damage.
2. Inner diameter matching
The inner diameter must strictly match the knife holder to prevent eccentricity, vibration, or unstable operation.
3. Thickness consistency
Blade thickness must remain uniform and properly matched with the clearance system. Incorrect thickness may lead to poor cutting quality or blade failure.
Material & Heat Treatment Selection
1. Material selection
SKD11 and SKH51 are suitable for high-strength materials, while ACD8 is suitable for thicker sheets and high-impact working conditions.
2. Heat treatment requirements
Blades must undergo uniform heat treatment (HRC 53–64 depending on material) and maintain excellent flatness and concentricity to ensure stable slitting performance.
Precision Requirements
1. High-precision applications
Used for transformer steel, precision strip steel, and other applications requiring high dimensional accuracy and long service life.
2. Clearance and overlap adjustment
Blade clearance and overlap must be properly adjusted according to material strength to balance cutting quality and tool life.
Important Note:
Slitting knives selection should be based on material properties, thickness, machine specifications, and precision requirements. Final parameters should always be confirmed through actual trial cutting to ensure optimal performance and cutting quality.