October 2008

Water jet cutting: easy machining for the hardest materials

NO DISTORTION – Water jet cutting removed a minimal amount of material, preserving the cylinder’s round shape during subsequent machining operations. Photo by Dan McKeeman/Atlantic Fasteners

For machining components made from composites and high-strength materials, water jet cutting offers significant advantages: shorter machining time, raw material cost savings, and a smoother kerf.

According to Dan McKeeman, director of Atlantic Fasteners’ made-to-print services division, the process is ideal for intricate cutting. “Water jet cutting is effective for any hard material, short of diamond,” explains McKeeman. Capable of producing a kerf as narrow as 0.05 inches wide regardless of material thickness, water jet cutting does not cause mechanical stresses or change the properties of the material, he notes.

McKeeman recently used water jet cutting to solve a customer’s problem that arose from machining a 12-inch-diameter pipe made of resin-hardened cloth layers, similar to phenolic material. The pipe needed to be split lengthwise with an “S” turn in the split for alignment purposes. Using a CNC milling machine to split the sections of pipe with an end mill wasn’t working. Even a small 3/16 diameter end mill was removing too much material, causing the round pipe to become egg-shaped. Without enough material left to restore the pipe’s concentricity and complete the finishing process, the customer was scrapping the part.

Water jet cutting removed a minimal amount of material, keeping the cylinder nearly round after being split. This enabled the customer to buy pipe with thinner walls, saving 30 percent, according to McKeeman. Using thinner material also cut machining time dramatically. In addition, the kerf was much smoother than end mill cutting.

Today, the customer trusts Atlantic to also do the finished machining of the split pipe when their own machine shop is too busy.

“Manufacturers should feel free to call Atlantic Fasteners with their cutting and machining challenges when their own machine shops are backed up or an outside vendor isn’t living up to their expectations,” says McKeeman. The Atlantic made-to-print services division can provide support and produce results quickly, he adds.