Wire EDM – The Remarkable Abilities

Wire electrical discharge machining (EDM) is used widely to create punches, mould components, special tooling, extrusion dies, airfoils, medical instruments, gear, tool holders, carbide cutters and thousands of workpieces too numerous to list. Wire EDM Tooling can be used to cut electrically conductive materials to make parts that require a high level of accuracy, intricacy and fine surface finish that is not achievable with traditional machining methods. Wire EDM unit can be programmed to cut complex shapes while there is no cutting force on the workpiece and no residual stress. There is little to no change in mechanical properties of the material. Wire EDM technology virtually leaves no thermal effects on the surface.

Wire EDM is best to cut extremely hard materials and rarely calls for expensive work holding fixtures.

The Working of Wire EDM

Wire EDM is an electrothermal production process where a thin single strand metal wire along with deionized water allows the wire to cut through metal by the use of heat from electrical sparks. The wire EDM works by creating an electrical discharge between the wire and the electrode and the workpiece. As the spark jumps across the gap, the material is removed from the workpiece and the electrode. Wire EDM can easily machine complex arts and precision components out of hard conductive materials.

Types and Size of Wire EDM

The wire used in EDM tooling process may consist of brass, zinc-coated brass, tungsten, molybdenum or a brass with a steel core. Each type of wire EDM has its own purpose, benefit and cost. EDM wire ranges in diameter from 0.0008 to 0.013 inch.

A 0.0008-inch wire EDM will produce 0.00044-inch radius in a corner a feature nearly impossible to manufacture any other way. The plain brass wire is 0.010 inch in diameter and is used in more than 80% of EDM work. These are of 3 types, hard, half-hard and soft. 

Wire with copper core and defused zinc outer layer is often referred to as high-speed wire or stratified wire and is used for roughing cuts.

No matter which type of wire you select, it can only be used once.

Tensile Strength of Wire 

The tensile strength of EDM wire is very important. Even though it does not touch the part during the cutting, but is stretched by the machine drive feed mechanism and if the wire does not have the tensile strength, it will break easily. However, wire with less tensile strength will cut angles without breaking. So, you need to buy the one according to your needs. For example, skim cuts require higher tension so slower speeds and less power are applied to achieve maximum surface finish and precision.

Maintenance

Wire EDM units require little maintenance which includes cleaning the orifices in the wire guides and the surfaces of the power contacts. Power contacts need to be indexed every 50 to 100 hours of cutting time and the wire rethreading mechanism should be checked and adjusted periodically. Follow the OEM’s recommendations faithfully to keep your machine running smoothly.

These are just a few of the abilities of the Wire EDM tooling and if you have been looking to buy a 3R system and CNC Pneumatic Chuck Systems you can rely on Maxx Tooling. They are a leading manufacturer and supplier of EDM tooling products providing custom design and manufacturing solutions. Visit the website today to browse the products you need or call them to know more.