Graphite Machining Tips from a Pro
The industry legend Tony Mucha's tips and tricks for adjusting to graphite's unique machinability characteristics is a must read for every EDM machinist.
Custom Graphite Machining at Tri-Gemini
Electrodes to your exact specifications; graphite or metallic, as well as graphite components for non-EDM applications. Redressing services are available to utilize the same block of graphite multiple times.
Copper Impregnated Graphites
Electrode materials with the brilliant surface finishes of copper and the machinability of graphite. Learn more about copper impregnation and the performance it will bring to your EDM operation
Technical Specification Overview
A quick breakdown of the key performance indicators (KPIs) for EDM operations and their relationship to graphite technical specifications
Metal/Material Removal Rate (MRR) - measured by volume of removed material over time. MRR is mostly influenced by power setting and the amperage applied to the electrode. When looking at graphite technical specifications both larger particle size & low electrical resistance will correlate to higher MRR. Performance will be lost in the form of rougher surface finish and an increased over-burn will need to be calculated into the electrode design.
Electrode Wear Rate (EWR) - There are three types of wear that an electrode will experience. Corner Wear, End Wear, & Side Wear. Corner wear is considered the most critical to high accuracy EDM operations. Small details and sharp corners generate the most sparks and thus are subject to the greatest heat exposure. Small particle size allows best EWR performance on these small details. This detail comes in a trade off with a slower MRR
Surface Finish (SF) - can be measured by VDI, Microns by micro-meter or micro-inch or various other conversions based on the manufacture of your EDM machine. Finer surface finishes can be achieved with smaller particle sizes. Amperage and polarity settings on your EDM machine can also be used to affect the finish.
Electrode Machinability - EDM graphite's incredible flexibility characteristics allow for machining of razor thin ribs and very small details into your electrode. Flexibility strength is shown in PSI on the below specification sheets. Optimum machinability can also be gauged by the shore hardness of the graphite. High 60's - Low 70's is ideal with harder graphite chipping more easily and softer graphite creating additional abrasion to the cutting tools.