Master steel rolls ready for slitting held together by black bands in a factory setting, which has a large yellow sky-hook and bright lighting.


The steel slitting process involves taking large coils of rolled steel (main or master coils) and creating smaller coils by slitting the sheet to two or more strands. It is typically the final step in steel processing and sets the final dimensions of the steel coils for manufacturing.


This process begins at the uncoiler, where the master roll is loaded. The metal is uncoiled and fed to the slitter. The slitting component is comprised of sets of rotary knives that are positioned with perfect precision to ensure proper final dimensions. After slitting, the metal is then wound into separate coils (mults) at the recoiler.

The downward view of slitting a master roll into two mults. The metal looks like a large piece of duct tape sliced down the middle and going down a deep concrete shaft with yellow, metal railing at the top of the shaft.


This process delivers steel coils that match the customer’s specific requirements, removes the need for processing of extra waste from the manufacturing workflow, and allows for the manufacturing of a variety of goods including pipes, tubes, straps and other applications.


The slitter recoiler system, with a large roll of metal wound around a huge metallic cylinder, which is part of a red machine.


Master coils are typically wider than the need for the final application, and the slitting process produces coils to the final specification. National Material of Mexico’s (NMM) slitting capabilities can handle thickness ranges from 0.009″ to 0.250″, and master coil widths from 12″ to 72″, creating up to 30 mults.


High strength steel, often used in automotive manufacturing, requires specialized slitting capabilities. NMM is proud to offer, among other steel service capabilities, the capabilities of the Red Bud Advanced High Strength Steel (AHSS) wide-slitting line. The Red Bud slitting line is capable of processing advance high strength steel and widths up to 72″ and sets a standard for performance and productivity.

A panoramic view of the Red Bud Slitting machine, with an uncoiled length of metal going down the slitting shaft, the red structure of the slitter extending around the factory floor, a workman in white hat and dressed in blue, and a rolls of steel waiting to be slitted.


The Red Bud line maximizes productivity and uses a “hand’s free” threading system that further improves safety and minimizes downtime, leading to faster turnaround. You can see this fantastic line in action here.


About National Material of Mexico– NMM is a subsidiary of National Material L.P. (NMLP), operating 16 steel service centers and processing facilities in the United States, Canada, and Mexico and shipping over 2,000,000 tons of steel annually. NMLP specializes in supplying, servicing, and processing steel with unmatched efficiency and capacity due to the company’s substantial list of capabilities. Proud to be ISO-certified and uncompromised in its safety standards for their employees, NMLP is a leader through efficiency, innovation, and performance.


National Material of Mexico is one of the largest steel service centers in Mexico serving automotive, HVAC, home appliance, motor and transformer manufacturers in Mexico. At NMM we specialize in storage and processing of hot rolled, cold rolled, grain oriented and non-oriented electrical steel, galvanized, galvannealed, aluminized, prepainted and other coated metals. NMM excels in supply-chain management, just-in-time programs and inventory control.

Become a customer today! For more information, visit our website: You can also contact us via our website, email our sales department at, or call us at 011-52-81-8319-4828.