Waterjet cutting: how it works, costs and design rules

A very high pressure stream of water mixed with abrasive cuts almost any flat material, including thick metal, stone, glass and composites, without heating it.

Typical tolerance

±0.1–0.25 mm

Quantities

1 to a few thousand

Lead time

2–10 working days

Materials

Almost anything flat, up to 100 mm+ thick

How it works

Water at up to about 4,000 bar passes through a small orifice with garnet abrasive. The jet erodes through the material along the programmed path.

Benefits

• No heat-affected zone, so material properties do not change.
• Cuts very thick plate and non-metals.
• No tooling.

Limitations

• Slower than laser on thin sheet.
• Edges taper slightly unless the machine compensates.
• Small inside radii limited by the jet diameter (about 0.5 mm).

What drives the cost

• Cut length and thickness.
• Edge quality setting (faster cuts leave rougher edges).
• Abrasive consumption.

Design rules

• Give inside corners at least 0.5 mm radius.
• Use waterjet for thick plate and heat-sensitive materials; use laser for thin sheet.
• Plan to machine critical faces afterwards when tolerance matters.

Preparing your STEP file

• Send a 1:1 DXF of the profile plus the material and thickness.
• Mark faces that will be machined later so the shop leaves extra material.

See also the full STEP export checklist and the comparison of all processes.