I'm curious how long I should be able to cut on my material support slats before I need to replace them? 

Thank you!

The answer to this question depends upon several variables. 1) What type of material do you typically cut? Thick metal? Thin metal? Foam? Cutting thick metal will cause you to wear out your slats quicker because the jet will always be moving slower across them. Cutting with foam and water-only, your slats should never wear out. 2) How good you are at alternating around your work envelope? If you always tend to cut your parts in the same area of the worktable, your slats will obviously wear out quicker in that area. To maximize the life of your slats, try cutting in different areas of the table to spread the cutting around. 3) How many hours a day/week do you run? Somebody running 2 hours per day will have their slats wear out much quicker than somebody running 16 hours per day. Generally speaking, if you don't pay any attention to where you are cutting, process a mixed batch of varying materials, and cut about 8 hours per day, expect your slats to last about 6-12 months. On the other hand, if you cut thinner materials, spread the cutting area around, run 8 hours a day, flip the slats upside down when they begin showing wear, you can easily expect to see 12 months or longer on your slats. Hope the info helps! Tim

Tim,
Good Info!

i cut some 38mm thick mild steel plates and my slats got cut straight through the 4" high slats

How slow were you cutting?  What was the condition of the slats before you cut the material?  If you were to cut at a 20% edge quality in the same spot a few times, you could certainly cut through.

they were actually pretty new slats... took them out and welded them back together...