The Basics of Sinker EDM Machining, Common Uses

In the world of fabricating and manufacturing, there are an awful lot of machines to familiarize yourself with. If you’re just starting out or if you’re expanding the scope of your tool, die and mold making operations you’ll want to know about the basics of Sinker EDM machining, or Electrical Discharge Machining. You’ll also want to know about the most common uses and applications for Sinker Electrical Discharge Machining. Here’s an intro to the basics of Electrical Discharge Machining and an overview of what you can use it for. 

What Is EDM?

First off let’s answer the basic question of what is EDM?  EDM is an acronym standing for Electrical Discharge Machining. Simply put, that means the process uses discharging pulses of electrical energy to erode (literally vaporize) metals or anything electrically conductive into shapes desired. The process of electrical discharging happens thousands of times per second and is controlled by the EDM machines generator.  If you have ever pulled a plug from the socket and seen a slight spark then noticed the resulting “burn” on the plug prong then you have witnessed EDM in action, just multiply that action by thousands of times per second and you can begin to imagine the forces capability to remove massive amounts of materials.

What Is a Sinker EDM?

The term “Sinker” became synonyms with 3D erosion in the EDM Process based upon the principle that electrodes were made (usually of graphite) in the reverse 3D image of the cavity to be burned. These electrodes are made slightly smaller to allow for that spark gap needed in the EDM process and suspended vertically from a machine's Ram.  During the process (which is bathed in non conductive oils) the machine slowly lowers the electrode into the workpiece as erosion takes place. This lowering, or sinking effect of the ram is how the term “Die Sinker” or the simpler term ”Sinker” came to be. 

How Does Sinker EDM Work?

So, how does Sinker EDM work? What is a sinker EDM? What is the sinker EDM  process? These are all important questions that you might have before being ready to make a decision when evaluating whether having a sinker EDM machine would add value to your shop or increase productivity. 

Here’s how a sinker EDM machine works, you submerge two conductive components in some insulated liquid (dielectric) that is used to control the spark, cool the workpiece and flush out the eroded particles. The Electrode is suspended from the Ram of the machine and the workpiece s mounted to the table. Each of these components are electrically connected to the machines Generator which is set on and off according to need. The controller will switch the current on and off automatically as needed in accordance with the parameters that were given for the project typically based on the electrode size and material removal rate as well as workpiece surface finish desired. Controlled erosion takes place when a series of powerful sparks are generated one after the other, gradually etching and burning away at the material until the desired shape is achieved.   

Sinker EDM vs. Other EDM Machining

While there are some notable differences between sinker EDM and other forms of EDM machining, the primary difference in most cases is the range of application. Now that we’ve answered questions like what is a sinker EDM and what is the sinker EDM process, you’re about to discover what you can use a sinker EDM machine for. 

Using an Sinker EDM allows you to machine any material, regardless of hardness as long as it is conductive. Advantages to this allow sinker EDM’s to be the last step in machining after workpieces have been sufficiently hardened for wear and other characteristics.  Unlike Milling which typically requires softer material to yield to the brute force of a cutter as well as requiring post machining polishing, the EDM Process never actually touches the material and usually requires no further working of the machined surface. 

Uses of a Sinker EDM Machine

With the more technical details out of the way, you’re now ready to learn more about what you and your shop can actually use a sinker EDM machine for. The most common applications for sinker EDM machines include the production of dies and molds with the production of plastic injection molding cavities being the single largest used for Sinker EDM machinery. 

The detailing made possible by the sinker EDM machine is incredibly helpful when creating these dies and molds in a shop as it can be done to finished hardened tooling. That said, having a sinker EDM machine on hand can make your shop more productive and ultimately help you make more money. 

You can also use a sinker EDM machine to make any number of other parts and components for different industries including the aerospace industry as occasionally engineers design components that can be machined by no other method and a Sinker EDM can be the only possible choice. Also many medical manufactures create implants and surgical tools that can only be produced by the Sinker EDM method. 

Check Out Our Used Sinker EDM Machines For Sales

If you’re looking for used sinker EDM machines for sale look no further than Southern Fabricating Machinery Sales!  Together our staff has over 60 Years of combined experience with Toolmaking and EDM Machining and can help you select the right Sinker EDM for your application and budget. Also we carry generous financing options that can help ease the purchase of new equipment. 

Check out our selection today and see what we can do for you!

When you want sinker EDM machines, you want Southern Fabricating Machinery Sales!