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Wires used in EDM machines

Dec. 27, 2021

Wire Tensile Strength

It is important to understand the tensile strength of EDM (electrical discharge machining) wire. Although the wire does not touch the part during cutting, it is tensioned by the wire-driven feed mechanism of the EDM machine, which consists of upper and lower feed contacts, roller guides and wire tensioners.

The wire is preloaded with tension, but the tension can be increased or decreased to achieve different cuts. The tensile strength determines whether the wire can withstand the tension applied to it during the cutting process. Wires with lower tensile strength are more likely to break, while wires with higher tensile strength are more difficult to break.

Low tensile strength wire can easily cut corners without breaking. The benefit of this wire is that angle cuts and tapers of up to 45 degrees can be achieved by simply offsetting or moving the guides on the UV axis. On the other hand, high tensile strength wire can be stretched more when the UV axis is used to better control the perpendicularity of the vertical wall for more accurate cuts.

In roughing, manufacturers often say that low line tension allows the machine to cut faster without breaking the line. They claim that skim cuts, on the other hand, require higher tensions, allowing for accuracy using less power and lower speeds.

Eco Friendly Wire Cutting EDM Machines


Wire Costs

However, low-tension wire costs more and is known for causing threading problems on automatic threader. Therefore, at LITONG GROUP, we have found a way to use high tension wire in almost all applications. This reduces our turnaround time and saves you money!

Today, EDM wire is typically sold in 16 kg (35.2 lb) spools. Under standard cutting conditions, this requires approximately 65 hours of cutting time.

Some EDM wire manufacturers offer larger spool options (even up to 100 lb. spools) for longer uninterrupted cutting times (up to 180+ hours of continuous cutting). In this case, a single spool can run 24/7 non-stop and can last more than a week before being replaced.


As with many industries, EDM service providers can be impacted by supply chain issues from overseas parts. We have always kept 6-7 months of wire in stock in our stores. This has helped us to weather the storm.

It's our job to get and keep EDM wire in stock with the proper tensile strength! With our expertise and experience, we will select the best wire for your project to produce the best results. If you have any questions or are ready to get started, please feel free to contact us.