ForMatter/Processes/subtractive/Water-Jet Cutting
proc_waterjet_cutting

Water-Jet Cutting

subtractive · abrasive waterjet, AWJ, high-pressure water cutting

Water at extreme pressure — sometimes mixed with garnet sand — cuts almost anything. No heat-affected zone. Cuts inch-thick steel, stone, glass, foam, food. Slow, wet, but the most material-agnostic cutting technology in the shop.

Cold cutting via 50,000–90,000 psi water stream, optionally laden with abrasive (garnet at 80–120 mesh). Pure water for soft materials; abrasive for hard. No HAZ — preserves tempered, hardened, or laminated structures that thermal processes would damage.

Scale & Tolerance

  • scale (mm)5 – 4000
  • tolerance (mm)0.2
  • skillbeginner to intermediate — CAD in, part out; tuning for thick or laminated stacks
  • min skillintermediate
  • whereschool shopprofessionalindustrial
  • costmoderate to high per part; capital cost high

Equipment

  • school_shopoccasionally — OMAX MAXIEM and Wazer desktop systems are reaching schools
  • professionalOMAX, Flow, KMT large-format flatbeds
  • industrial5-axis water-jet for bevel cuts; tilting heads for taper compensation

Environmental

  • energy_usehigh (intensifier pump)
  • waste_streamspent garnet + cut slurry — most facilities settle and recycle the garnet
  • consumablesgarnet abrasive, focusing tube, orifice

Trade-offs

constraints · what is lost · what is gained
Steel 1018 (Mild Steel)
  • constraints
    • minimum kerf ~0.5–1 mm (abrasive jet) or 0.1 mm (pure-water jet on soft materials)
    • taper on thick stock (the jet diverges below the cut-zone); thick parts need taper-compensation
    • no heat-affected zone — material properties unchanged at the edge
  • what is lost
    • matte / abraded edge texture — different from laser's heat-discolored edge
    • striations in thick stock from jet deflection during cut
  • what is gained
    • cuts virtually every solid material — metal, glass, stone, composites, foam — with the same machine
    • no thermal damage to the substrate (critical for hardened steels, composites, food-contact)
    • thicknesses to 200+ mm with multi-pass technique

Plain language. Neutral framing — perfection is contextual, defined by use. Cf. Winchester, The Perfectionists (HarperCollins, 2018).

Second life

reversibilityzero — the cut is permanent.
output recyclabilityyes
waste streams
  • spent abrasive (garnet — recyclable in some systems for several passes before disposal as aggregate)
  • cut-water (closed-loop in modern installations; the slurry is filtered and reused)
  • cut-metal scrap (recoverable if collected)
repair compatible withproc_tig_welding, proc_adhesive_bonding

WJTA Waterjet Technology Association literature; Flow / OMAX / KMT waterjet technical guides.

Citations

  • book · Lefteri, *Making It: Manufacturing Techniques for Product Design*, 2nd ed. (Laurence King, 2012), 'Water-Jet Cutting' p. 42.