A Guide to Steel Processing

By October 24, 2017News, Your Advantage

At Pacesetter, we start with prime flat rolled steel (from domestic and offshore mills) to provide our customers with galvanized, cold rolled, galvanneal, aluminized, stainless, and bonderized steel products.

Pacesetter offers three traditional services which include, slitting, blanking / multi-blanking and cut-to-length. Other services that can be added while processing in our service centers are beading sheets and adding strippable. Some of Pacesetters outside processors can perform additional processes such as embossing, perforating and prepainting.

Basic Processing: Slitting, Blanking and Cut-to-Length

Slitting steel is, essentially, a cutting process. Large rolls or coils of steel are cut lengthwise to create strips of metal that are narrower than the original in width. This is an automated process where the master coil is run through a machine that has very sharp rotary blades, one upper and one lower, often called “knives.”

While the knives, clearly, are key to the process the un-coiler, knives and re-coiler must all be aligned and set correctly (knife clearance and uncoil/recoil tension levels are critical) in order to avoid problems. Dull knives along with a bad set-up can lead to burred edges, edge wave, camber, crossbow, knife marks, or slit widths that don’t meet specs.

Another basic processing application is blanking.  A blanking line will uncoil the material, level it, and cut it to a specified length and width.  As a result, a blank normally goes directly into the manufacturing process without being re-sheared. In order to achieve the desired tolerance, blanking lines utilize a close tolerance feed system, side trimmers and in-line slitters.

Cut-to-length lines are generally thought of as systems that produce sheets. Sheets are cut to a standard size and typically re-sheared at the end user. In order to achieve flatness tolerances, cut-to-length equipment needs to have precision corrective levelers. These levelers elongate the steel beyond its yield point (the amount of stress the steel can take at the onset of permanent deformation) in order to remove internal stresses and produce a flat sheet.

Common Finishing Options in Steel Processing

The most common method of perforating metal uses a rotary pinned perforation roller. This is a large cylinder with sharp, pointed needles on the outside to punch holes into the metal. As the sheet metal is run across the perforation roller, it rotates, continuously punching holes in the passing sheet. The needles on the roller, which can produce a wide variety of hole sizes, are sometimes heated to simultaneously melt the metal which forms a reinforced ring around the perforation.

Pre-painting steel is common customer need. Pre-painted steel is produced by a direct application of paint (after cleaning and priming) onto steel sheet in a coil-coating line. Coil-line painting can be used to apply a paint coating directly on the uncoated steel sheet or on metallic-coated steel sheet, including galvanized. Pre-painting increases the anti-corrosive properties of steel.

Embossing is a metal forming process for producing raised or sunken designs or relief in sheet material by means of matched male and female roller dies, theoretically with no change in metal thickness, or by passing sheet or a strip of metal between rolls of the desired pattern.

Finally, there is fabrication, where steel is actual made into a “part.” Usually the metal is bent, or formed, into specific shapes to be used in manufacturing. Fabricating can create a piece that’s as complicated as a car body, or as simple as a panel.

Steel is strong, durable and the ideal material for everything from HVAC ductwork to railway cars. It takes steel processing and finishing to turn a master coil into a finished part.