A Hydro-Cut Case Study:

Plasma vs Water Jet Metal Cutting

Customer:  Milacron

Part Name:  Jam Bar

Material:  Alloy Steel Plate - A514 Grade H

Background:  A jam bar is part of the safety system for a plastic injection molding machine.  The steel is 1.75” thick and the parts are roughly 4” wide and 90” long.  The customer was having difficulty obtaining parts in a timely manner due to additional secondary processing required to finish the part.

Problem:  The customer had been having the jam bar “blanks” plasma cut.  The heat put into the steel during that cutting process created three problems—the first being straightness; the second being flatness; and the third being the hardening of the cut surface of the steel.  After receiving the plasma cut parts the customer had to have them flattened and straightened.  The parts then required additional machining.  Machining the hardened surfaces used more tools due to wear and breakage, and it took more time.

Solution:  Abrasive water jet cutting does not use heat and therefore does not warp or harden  material.  Parts cut with water stay flat and straight and are easy to machine.

Return:  Even though using a water jet metal cutting machine was slightly more expensive than
plasma cutting, the customer saved money in the long run by eliminating some secondary processes and reducing the time and cost of required machining.