What process is better; laser cutting, waterjet cutting, CNC punching, or metal stamping?

Each process has its strengths and limitations in terms of cost, edge quality and accuracy. The manufacurers of the equipment often downplay the limitations which can include nibble marks, dross, scratching, taper, oxidization, scaling, burrs, speed and finish quality. We will recommend the best process to you based on our knowledge of each process and your application.

If you have many holes, as electronic chassis tend to have, CNC punching is often the best method because of punching speed, roundness of holes, and the ability to form features and tap holes. In thin gauge materials that have curves or long cut lines, laser cutting is often the fastest.  A flying optics laser minimizes scratches on the material and can eliminate microjoints. A steel part, laser cut with oxygen assist gas, can have scaling on the edges that can produce problems in welding and powder coating so nitrogen gas is often used. As soon as the material approaches half an inch in thickness, waterjet produces superior edge quality. You can also stack material on a waterjet machine and the cold processing allows welding and powdercoating without problems. Copper parts are too reflective to cut on a CO2 laser so waterjet or a fibre laser is often the best process to minimize wastage of the expensive material. Metal stamping can reduce the part cost by an order of magnitude and becomes cost effective when run sizes are 1000 or more or repeat often. EDM is the highest precision cutting method but it is also the most expensive.

KERF WIDTH

Laser .008"-.025", changes with material thickness.
Wire EDM .012"-.013 if using a .010" wire.
Waterjet .020"-.060", depending on mixing tube and orifice used.

ProcessAccuracySpeedEdge QualityOther Benefits
EDM (Electrical Discharge Machine)+/- .0001"SlowHighAdjustable Taper
Machining+/- .001"MediumHighMilling, Turning
High Volume Metal Stamping+/- .001"HighHighForming
Water Jet+/- .003"MediumMedium - taperCopper, stone, chicken, diapers
Laser+/- .004"High in thin materialsMedium - dross, breakawayNo tabs
CNC Punch Press+/- .005"High with holesMedium -nibble marksForming, tapping, countersinking