Metal Fabricating & Small Lot Division

Metal Fabricating

The advent of CNC–controlled laser–cutting, press–brake and punch–press machinery allows rapid production of parts with little setup—and little cost related to tooling. CNC punch presses, sometimes referred to as punching machines, manipulate a sheet of material on a table where it is shaped or punched by tools contained in a turret or other tool–holding apparatus. The press chooses, based on instructions, the appropriate tool for that particular operation. These presses contain various standard tools that allow for great machine flexibility in punching, slotting, bending and a host of other operations.

Laser cutters use a laser—typically CO2—positioned over a sheet on a worktable to cut-actually melt or vaporize—the sheet to the desired profile. Shielding gases allow for smoother material edges or increased material combustion.

Press brakes provide bending operations, typically on relatively longer and slimmer workpieces.

Laser cutters and CNC punch presses often are used together in cells, or the two are combined into one machine. Sometimes press brakes are teamed with a robot in an automated bending cell.

Small Lot Stamping

Small lot stamping is the production of stamped parts in relatively low quantities and often with short lead times, enabling improved inventory control for the customer but demanding flexibility in production and the capability to perform rapid job changeover for the stamper.   

Stampers focusing on small lots must be in possession of a large number of part jobs to remain profitable. They also must often carry a high amount of customer inventory. With so many different parts to be produced in compressed lead times, small lot stampers are constantly under pressure and must make their operations as efficient as possible. This means adopting quick–tool–change capability and efficient tool warehousing; acquiring and honing the ability to supply parts in a just–in–time fashion; and developing and maintaining an organized production, inventory, shipping and record-keeping system. Small lot production demands flexible equipment and strict preventive–maintenance procedures to prevent vital tooling and machinery from failing—even limited unscheduled downtime can cost a small lot stamper, and the customer, dearly. To protect against downtime problems, small lot stampers and customers may agree to warehouse certain parts to ensure their supply.

Because part runs are smaller and dedicated tooling still must be built, piece prices may be higher than for longer–run jobs. On the other hand, tooling need not be as hardy for smaller–run jobs, so some cost savings may result.

In recent years, many small lot stampers have incorporated fabrication equipment such as press brakes, turret punch presses and laser–cutting machines to handle very low–volume part runs and prototype production. This equipment does not require dedicated tooling, often resulting in piece-part savings compared to production on stamping presses.

For more information, contact Allison Grealis at 216-901-8800 ext. 104 or agrealis@pma.org.