Steel slitting is an essential process in the metals supply chain.  By slitting large steel coils into narrower coils or strips, steel suppliers can provide the customized strip widths needed by end users in industries from construction to appliances and automotive manufacturing.  In this blog, we’ll look at the basics of what steel slitting entails and how it benefits metal producers and consumers.


WHAT IS STEEL SLITTING?

Steel slitting is the process of cutting wide steel coils lengthwise into multiple narrower coils or strips.  It emerged as an efficient alternative to time-consuming and labor-intensive methods of slitting metal, such as band saws or cut-to-length operations.  With high-speed steel-slitting lines, steel suppliers can process more material faster and supply slit coils and sheets more cost-effectively.


HOW DOES METAL SLITTING WORK?


During the slitting process, a steel coil is loaded by crane onto a decoiler, which feeds the coil into the slitting line.  As the coil feeds through the line under tension, rotary slitting blades slice the width into the required strip widths and gauges.  Slitting blades typically slice the steel cleanly and precisely from edge to edge with minimal material loss.


After slitting, the coil can be edge-trimmed, leveled, recoiled, or cut to length.  The finished slit steel output is then usually packaged and shipped to customers.  Depending on the application, common slit widths can range from 1/2 inch up to 60 inches.  Slitting lines can accommodate steel coils up to 1/4 inch thick and over 60 inches wide.


SLITTING EQUIPMENT

Various types of metal slitters are available, from single-shaft equipment to high-volume, multi-shaft slitting lines, each with advantages and limitations.  High-speed steel razor slitters are the most common machines used today since they produce clean and accurate slit edges even on high-strength steels.


Below are a few of the main types of slitting equipment:


Slitting Saws are circular saws with hardened teeth that spin to cut metal widths.  They are typically best for shorter runs.

Rotary Shear Slitters are rotating blades that use a scissor-like shearing action to slit the coil clean through, leaving no residual saw teeth marks.

High-Speed Steel Razor Slitters are carbide blocks with razor blades attached that slit with precision at high speeds, leaving a smooth edge finish.  Most modern lines use razor slitters.

TYPES OF SLITTING STYLES

Different Metal Slitting Styles


The two main styles of slitting are longitudinal and crosscut slitting.  Let’s take a more in-depth look at these two types.


LONGITUDINAL SLITTING


Longitudinal slitting is most common for coil processing.  The process involves cutting wide coils into narrower strips, typically in a continuous manner, where the cutting direction is parallel to the length of the original metal coil.


The end product of longitudinal slitting is narrow strips or coils of material with customized widths.  These strips are used in various applications, including roofing, construction, automotive components, and more.


CROSSCUT SLITTING


Crosscutting allows slitting sheets into smaller sheets or strips.  The process involves cutting wide sheets or coils into shorter lengths to create individual pieces.  In this instance, the cutting direction is perpendicular to the length of the original metal coil.


The end product of crosscut slitting is individual sheets or smaller lengths of material.  These sheets are often used for packaging, manufacturing smaller parts, or any application that requires shorter pieces of material.


BENEFITS OF SLITTING

There are several key benefits to slitting steel coils and sheets compared with other methods, including better efficiency, precision, and cost savings.


1.  COST SAVINGS


Slitting is a continuous operation that is far more cost-efficient per pound than cutting sheets from a shear.  Slitting one wide coil on a high-speed line equates to multiple cuts from a sheet shear or sawing operation where labor, time, and consumable blade costs add up.


For example, slitting a 40,000-pound coil into ten slit coils takes less than an hour.  Comparatively, shearing 40,000 pounds of sheets would take 8-10 hours or more of cutting time while wearing shear blades faster in the process.


2.  CUSTOMIZABLE


Slitting enables steel suppliers to produce coils and sheets in custom widths based on customer needs, reducing the need for additional processing.  For example, rather than purchasing a standard width sheet, slitting allows custom widths like 15.875″ for specific parts or roll-forming applications.


3.  PRECISION TOLERANCES


Modern high-speed slitting lines with razor slitters can hold extremely tight width tolerances.  This precision permits steel to be used directly in automated stamping presses or CNC machining centers with minimal secondary processing required.  Similarly, slit-edge squareness of under .010″ per inch of coil width is standard.  Customers can stamp or form parts t