ELECTRICAL DISCHARGE MACHINING (EDM)
With over 100 years combined experience and the latest state-of-the-art software and equipment, HDT’s EDM technicians are among the best in the industry. Our team has provided high quality EDM manufactured products to clients in a variety of major markets including automotive, aerospace, defense, medical, and agriculture to name a few. Our machine capacity can handle parts ranging from .040” in diameter to 20” x 30” x 14” with the ability to offer surface finish control without compromising structural integrity.
The knowledge and expertise of our certified EDM technicians is second to none. Our team looks forward to a challenge and the chance to demonstrate the extraordinary craftsmanship that can be achieved through skilled EDM manufacturing.
Electrical Discharge Machining is an advanced machining technique that allows for precise, detailed cuts that were once thought to be out of reach with traditional machining. Years ago, EDM machining was used mainly for mold-making, however it has now become a crucial part of tool making especially for prototype and production work. With the ability to repeatedly and consistently complete parts with minute tolerances, EDM machining has become the ideal solution for manufacturing parts with unique cuts, angles, tolerances and materials. Materials used in the EDM process must be electrically conductive such as copper, aluminum, bronze, tungsten, carbon steel, high alloy, Inconel, Hastelloy, medical grade stainless steel or carbon graphite.
Header Die & Tool employs three types of EDM technologies in an effort to offer our customers the best solution for their machining needs.
The Wire EDM process is achieved by creating an electrical discharge between the wire and the workpiece. A spark is sent from the shortest distance between a single strand of wire, usually brass, and the workpiece where it jumps the gap (known as the spark gap) at which point material is burned away from the workpiece. In order to control the sparking process from shorting out, dielectric, a non-conductive fluid solution is used to either flush or submerge the entire Wire EDM process. The eroded waste material is removed by the continuous flow of the dielectric fluid which is cooled and filter throughout the entire process. Since Wire EDM is mainly used for cutting shapes through assemblies and inserts, it is usually necessary to predrill a hole for the wire to be fed through in order for machining to be completed. The Wire EDM process is utilized only when the required cut goes through the entire workpiece.
BENEFITS OF WIRE EDM
- Precision cuts; Wire EDM accuracy can be within +/- .0003”
- Internal corner cuts with nearly square edges
- Ability to cut long tapers that would otherwise be impossible
- More accurate production & prototype runs with shorter lead times
- Capability to accurately and repeatedly machine delicate & intricate parts with no deflection
- Wire EDM does not generate burrs
- Does not require tooling
- Ability to machine pieces up to 12″
- Machining takes place after heat treatment so dimensional accuracy is not affected by heat treat distortion
WIRE EDM SPECIFICATIONS & CAPABILITIES
- Maximum angle for taper is 45°
- Maximum cutting height is 16.5”
- Tolerance can be maintained to .0003”
- Wire Diameters from .002”-.010”
- Materials from copper, bronze, tungsten, carbon steel, high alloy, Inconel, hast alloy, stainless steel or carbon graphite
- Maximum weight for workpiece: 1800 lbs.
- Maximum angle: +/- 10° at 12” thick workpiece; 30° at 3.25” workpiece; 45° at 1.93” workpiece
- Maximum travel: X=21.7”, Y=14.6”, Z=12.2”
CONVENTIONAL or RAM EDM (DIE SINKER EDM)
Conventional EDM is commonly known as Spark EDM. This process is often used when the desired cut or design feature does not penetrate through the entire workpiece. Electrodes for Spark EDM are mostly manufactured from graphite or copper tungsten. RAM EDM electrodes utilize a negative-formed shape which contains all the detail of the final workpiece. Through CNC programming, the electrode is moved along the workpiece, never contacting the piece but creating an area between the electrode and workpiece referred to as Spark Gap. As the electrode moves along the x, y, c, and z axes, complex indentations, shapes, vents and cavities are created. The intricacy that can be achieved with conventional EDM is unmatched by any other method of machining.
Typically RAM EDM applications are performed with the workpiece fully submerged in solution bath. This fluid serves various purposes including flushing away of the eroded material, cooling the heat affected zone and preventing damage to the workpiece, and acting as a conductor between the electrode and the workpiece. Spark EDM has become a standard method for machining production prototypes due to the precision and abstract cuts allowed by EDM that are not available through alternative machining systems.
HDT electrodes are created through a 4-axis high speed milling process. Our electrodes are milled to completion and incorporate all features of the final product with no hand-scraping required.
Benefits of RAM EDM
- A variety of shapes and sizes inside blind cavities
- Remarkable accuracy and fine finish control with no compromise to structural integrity
- Shapes are burned into hardened materials eliminating the chance of size change caused by heat treating
- Production with greater consistency, repeatability, and efficiency
- Little required tooling means reduction in set-up time
- Internal splines, blind keyways, molds
- Hexes for special bolts and parts & helical cut gears and shapes
- Complex shapes that would otherwise be difficult or impossible to produce with conventional cutting tools
- Extremely hard material machined to very close tolerances
- Very small work pieces where conventional cutting tools may damage the part from excess cutting tool pressure
- There is no direct contact between tool and work piece. Therefore delicate sections and weak materials can be machined without any distortion.
Small Hole Drill EDM (Hole Popping)
Small hole drilling EDM machining allows a 0.3mm-6.1mm diameter hole to be drilled through a 100mm piece of soft or hardened steel in about 10 seconds with an average wear rate of 50% to 80%. This process uses a long brass or copper electrode in the form of a tube. The electrode is held in a chuck and rotated as a flow of distilled water flows through the electrode and flushes away the eroded material.
Though small hole drilling EDM was initially used mainly for pre-drilling holes for wire EDM, its uses have since become more widely recognized. Mold and part manufacturing-injection nozzles, oil drain holes, hydraulic cylinders and dowel pins, as well as turbine blades, ball bearings and safety wire holes in hex nuts are just some of the manufacturing areas that benefit from the use of small hole drill EDM.
HDT has found that small hole drill EDM also has a place in venting, small ID work as well as workpieces with small diameters.
BENEFITS OF SMALL HOLE DRILL EDM
- Less time spent means shorter lead times
- Drilling is done into hardened materials eliminating the chance of size change caused by heat treating
- Little required tooling means reduction in set-up time
SMALL HOLE DRILL EDM SPECIFICATIONS & CAPABILITIES
- x-axis movement 6.75”
- z-axis movement 10.75”
- Axis vertical movement (w-axis 8.5”
- Maximum workpiece weight 440lbs
- Maximum workpiece dimensions (14.5” x 15” x 10.75”)