Advantages

Abrasive waterjets have many advantages over other machining methods:

• Wide range of materials
  Abrasive waterjets can machine a wide range of thicknesses and materials, including metals, plastics, glass, and ceramics.
• Quality finish
  Materials cut by the abrasive waterjet have a smooth, satin-like finish, similar to a fine sandblasted finish.
• No heat in machining process
  Abrasive waterjets abrade material at room temperatures. As a result, there are no heat-affected areas or structural changes in materials. Abrasive waterjets can also machine hardened metals and materials with low melting points.
• Environmentally friendly
  Abrasive waterjets use garnet as an abrasive. Garnet is a reddish natural crystal, with a Moh's hardness of 6.5 to 7.5. No noxious gases or toxic liquids are used in abrasivejet machining.
• No tool changing
  A wide range of conventional processes can be performed with this single tool:
  • Drilling
  • Sawing
  • Broaching
  • Gear cutting
  • Profile milling
  • Punching
  • Slitting
  • Spline cutting
  • Blanking
• Minimal burr
  No heavy burrs are produced by the abrasivejet process. Parts can often be used directly without deburring.

Comparing abrasive waterjet machining

Comparing abrasive waterjet to wire EDM

Key Wire EDM strengths

• Extremely precise parts are possible [±0.0001" (±0.025 mm)]
• Very thick parts [over 12" (30 cm)] can be made
• Intentional taper can be put into a part for die clearance and other uses

Key Precision abrasive waterjet strengths

• Five to ten times faster in parts less than 1" (2.5 cm) thick [but, at ±0.003" (±0.1 mm), less precise as well]
• No Heat Affected Zone (HAZ), so no need for secondary operations to remove the HAZ or additional heat-treating to compensate for it
• Works well in non-conductive materials (such as glass, stone, plastic) as well as conductive materials
• Can pierce material directly without the need for a pre-drilled starter hole
• Can produce large parts at reasonable costs
• Simple programming and rapid set-up with minimal fixturing

Comparing abrasive waterjet to laser

Key Laser strengths

• Very fast production in thin, non-reflective materials such as sheet steel.
• Accuracy to ±0.001" (±0.025 mm) or better in thin material.
  

Key Precision abrasive waterjet strengths

• Can produce parts up to 2" (5.1 cm) thick in virtually any material while holding tolerances on the order of ±0.003" to ±0.005" (±0.08 to ±0.1 mm).
• Can machine reflective, conductive and thicker materials such as stainless steel and aluminum, copper and brass.
• Cuts without melting, providing a smooth uniform surface with very little burr or dross.
• No heat-affected zone (HAZ), which may eliminate the need for a secondary operation to remove HAZ and makes conventional secondary operations, such as reaming or tapping, easier to perform.
• No noxious gas or vapors produced during cutting.
• Simple programming and rapid set-up for short-run parts.

Comparison of precision abrasive waterjet to milling

Key mill or machining center strengths

• A well-understood familiar technology.
• Able to make three-dimensional parts.
• Rapid production if set up and programmed for long-run parts.

Key precision abrasive waterjet strengths

• Very rapid programming and set-up does not require a highly trained operator.
• Very low cutting loads means that fixturing is easier and also means that intricate and delicate parts can be machined.
• One cutting tool performs all machining functions in all materials, so there is no need to purchase and calibrate multiple cutting tools.
• Large cutting envelope compared to a machining center of comparable price.
• Minimal burr compared to conventional machining.
• Environmentally friendly; no oil-soaked chips and minimal scrap.

Comparison of precision abrasive waterjet to a punch press

Key punch press strengths

• A well-understood familiar technology.
• Rapid production in thin material once the machine is properly programmed and set-up.
• Relatively low capital cost (although tooling costs can add up).

Key precision abrasive waterjet strengths

• Very rapid programming and set-up for short run parts.
• No distortion of closely spaced parts.
• Minimal burr.
• Ability to work in a wide range of thickness, from sheet metal to plate.
• Ability to work in a very wide range of materials.
• No special tooling required for unusual shapes or profiles.

Comparison of precision abrasive waterjet to high-definition plasma

Key strengths of high-definition plasma

• Relatively low capital costs.
• Very rapid production rates in thin sheet metal, once properly set up and programmed.

Key Precision abrasive waterjet strengths

• No melting or heat-affected zone, so no heat distortion or crusted area to impair secondary machining processes such as tapping holes.
• Wider range of material capabilities.
• Wider range of thickness capabilities.
• Better precision in intricate parts

*Courtesy of Omax Corporation