Metal Slitting Knives

Metal Slitting Knives

Persistools metal slitting knives are precision circular cutting tools used in rotary slitting lines to divide wide metal sheets or coils into multiple narrow strips.

The knives are installed in matched positions on upper and lower slitting shafts. During operation, the cutting edges overlap with controlled side clearance, creating a continuous shearing action as the metal strip passes through the machine.

Unlike rewinder slitting systems that use a dedicated top and bottom knife structure, metal slitting lines typically use multiple identical circular knives arranged alternately across the two shafts.

This allows one wide sheet to be divided into several strips in a single pass.

Double-Edge Cutting Design

Most metal slitting knives use double-sided cutting edges.

This provides two usable working edges on the same knife and improves service life before replacement or regrinding.

The double-edge design is particularly suitable for continuous strip slitting, where multiple knives must maintain consistent geometry across the complete shaft.

TCT-Tipped Construction

Most modern metal slitting knives use a tool-steel or high-speed-steel body with a brazed tungsten carbide outer ring.

This construction combines:

• Tough steel core
• High wear resistance at the cutting edge
• Better impact tolerance than solid carbide
• Lower manufacturing cost
• Easier production of larger diameters
• Long service life in continuous slitting

The tungsten carbide ring is concentrated in the working area where wear is highest.

Solid Carbide Designs

Solid carbide metal slitting knives were used in some specialized applications where extremely high wear resistance was required.

However, because large solid carbide circular knives are expensive to manufacture and more sensitive to impact, they are now less common in general metal slitting applications.

TCT-tipped designs provide a more practical balance between cost, toughness, and cutting life.

Controlled Shear Clearance

Metal slitting quality depends heavily on the relationship between:

• Knife overlap
• Side clearance
• Blade thickness
• Spacer accuracy
• Shaft runout
• Cutting-edge parallelism

Elastic or precision spacer systems are used between the knives to control the working position and penetration depth.

Because thin metal sheet requires only limited overlap, the cutting depth is relatively shallow.

Correct setup helps maintain:

• Uniform strip width
• Clean slit edges
• Reduced burr formation
• Stable cutting load
• Lower edge deformation
• Consistent multi-strip production

Typical Applications

Persistools metal slitting knives are commonly used for:

• Carbon steel strip
• Stainless steel strip
• Electrical steel
• Copper strip
• Aluminum strip
• Galvanized sheet
• Coated metal sheet
• Thin metal coil processing

Knife diameter, thickness, bore, carbide grade, edge geometry, and clearance requirements can be customized according to material type, sheet thickness, line speed, and slitting width.