advantage of wjm over lasers

• Abrasive waterjets can machine many materials that lasers cannot. (Reflective materials in particular, such as Aluminum and Copper.
• Uniformity of material is not very important to an Abrasivejet.
• Abrasive jets do not heat your part. Thus there is no thermal distortion or hardening of the material.
• Precision abrasive jet machines can obtain about the same or higher tolerances than lasers (especially as thickness increases).
• Your capital equipment costs for water jet are generally much lower than that for a laser. I.e. for the price of a laser, you can purchase several abrasivejet-machining centers.
• Abrasive jets can machine thicker materials. How thick you can cut is a function of how long you are willing to wait. 2" (50mm) steel and 3" (76mm) aluminum is quite common. I heard of people doing up to 10" (250mm) steel, and 24" (600mm) thick glass with high horsepower systems. Once you get over 2" (50mm) thick it is very difficult to get precision, however. Lasers seem to have a maximum of 0.5" (12mm) - 0.75" (19mm).
• Abrasive jets are safer. No burnt fingers, no noxious fumes, and no fires. (You still have to keep those fingers out of the beam.)
• Abrasive jets are more environmentally friendly.
• Maintenance on the abrasive jet nozzle is simpler than that of a laser, though probably just as frequent.
• Abrasive jets are capable of similar tolerances on thin parts, and better on parts thicker than .5"
• Abrasive jets do not loose much "focus" when cutting over uneven surfaces.
• While lasers are often faster on thinner materials...
• it may be cheaper and faster to simply buy two or three abrasive jet machining centers to do the same work
• you can stack materials, so you are cutting multiple thin parts simultaneously.
• you can run additional cutting heads in parallel on a single machine
• Modern Abrasive jets are typically much easier to operate and maintain than lasers, which means that every employee in your shop can be quickly trained to run one!
• Abrasivejets don't create "scaley" edges, which makes it easier to make a high quality weld
• Many shops that have lasers also have waterjets, as they are complimentary tools. Where one leaves off, the other picks up.