Water Jet Cutting FAQ

A water jet cutter is a tool capable of slicing into metal or other materials using a jet of water at high velocity and pressure, or a mixture of water and an abrasive substance. the process is essentially the same as water erosion found in nature but greatly accelerated and concentrated. It is often used during fabrication or manufacture of part for machinery and other devices. It is the preferred method when the materials being cut are sensitive to the high temperatures generated by other methods. It has found applications in a diverse number of industries from mining t aerospace where it is used for operations such as cutting, carving and reaming.

In the 1950’s, forestry engineer Dr. Norman Franz experimented with an early form of water jet cutter to cut lumber. However, the technology did not advance notably until the 1970’s when Dr. Mohamed Hashish created a technique to add abrasives to the water jet cutter. Today the water jet is unparallel in many aspects of cutting and has changed the way many product are manufactured. Many types of water jets exist today, including plain water jets, abrasive water jets, percussive water jets, cavitation jets and hybrid jets.

The cutter is commonly connected to a high-pressure water pump where the water is ejected from the nozzle, cutting through the material by spraying it with the jet of high-speed water, Additives in the form of suspended grit or other abrasives, such as garnet and aluminum oxide, can assist inn this process.

An important benefit of the water jet is the ability to cut material without interfering with the material’s inherent structure as there is no “heat affected zone” or HAZ. Minimizing the effects of heat allows metals to be cut without harming or changing intrinsic properties.

Water Jet cutting is considered a “gree” technology. Waterjets produce no hazardous waste, reducing disposal costs. They can cut off large pieces of reusable scrap material that might have been lost using traditional methods. Parts can be closely nested to maximize material use, and the waterjet saves material by creating very little kerf. Waterjets use very little water (a half a gallon to approximately on gallon per minute depending on cutting head orifice size), and the water that is used can be recycled using a closed-looped system. Wastewater usually is clean enough to filter and dispose of down a drain. the garnet abrasive is a non-toxic natural substance that can be recycled for repeated use. Garnet usually can be disposed of in a landfill. Waterjets also eliminate airborne dust particles, smoke, fumes, and contaminants from cutting materials such as asbestos and fiberglass. This greatly improves work environment and reduces problems arising from operator exposure.

1. Uses a high velocity stream of abrasive suspended in a stream of Ultra High Pressure Water (30,000 – 90,000 psi) which is produced by a Waterjet Intensifier Pump.

2. Is used for machining a large array of materials, including heat-sensitive, delicate of very hard materials.

3. Produces no heat damage to work piece surface of edges.

4. Nozzles are typically made of sintered boride.

5. Produces a tapper of less than 1 degree on most cuts, which can be reduced or eliminated entirely by slowing down the cut process or using a dynamic waterjet head.

6. Distance of nozzle from work piece affects the size fo the stream width and the removal rate of material. Typical distance is .125″