Introduction of an ultra-fine wire used in wire-cutting of special electrode products that KANOU Japan is providing to our Chinese customers: SP WIRE.

Main applications of SP Wire electrode wire

In the past, only tungsten wire and molybdenum wire can be used for ultra-precision and micro-machining (processing of electrode wire diameters below 0.1 mm).

Now SP WIRE has been recommended as the most suitable electrode wire by major EDM (Electrical Discharge Machining) users.

• Electrode wire for ultra-precision mold processing

Molds for Lead frame, connector, engineering plastic & precision parts.

• Wire electrode for micro-EDM

Precision gears, fiber spinning nozzles, odd profile molds, precision component processing, and micro-hole processing.

Overview of SP Wire electrode wire

It is a two-layer hybrid electrode wire with a core wire made of high-strength special steel wire (piano wire) and an outer layer made of brass with superior conductivity. It combines the advantages of tungsten wire and brass wire. SP Wire is developed by combining filament processing technology and superb surface treatment technology obtained through many years of research and development.

SP Wire not only has high tensile strength and excellent discharge performance, but also has excellent performance in all aspects such as processing characteristics, mechanical/electrical properties, and cost-effectiveness. In the field of difficult and ultra-precise wire cutting processing, it is a high-performance electrode wire that completely surpasses traditional brass wire and tungsten wire.

 SP Wire electrode wire – Unique Features

A composite electrode wire composed of a core wire with high tensile strength and a brass coating with excellent electrical conductivity. Therefore, in general applications, it not only has the same tensile strength as tungsten wire, but also has better discharge performance than brass wire, and can effectively reduce the wear on the roller shaft, guide rail & other wire feeding systems.

In the field of ultra-precision machining, it is unquestionable that SP Wire electrode wire is more superior than tungsten wire.

In areas where brass wire is being used, SP Wire is also easier to perform precision cutting processing than brass wire due to its high tensile strength.

In addition, when processing corners, the R angle can be made smaller due to the narrow cross-section of SP Wire; when processing the same R angle, compared with other electrode wires, SP Wire can choose a thicker wire diameter grade, thereby achieving faster cutting speed.

Therefore, in the field of fine wires with a wire diameter of less than 0.1 mm, if the usual combination of using both BS wire & SP wire is replaced with only SP wire, the changes during the processing operations can be reduced drastically. Combining the above conditions, the processing time can be shortened, leading to reduction of cost & delivery leadtime.

SP Wire electrode – Processing characteristics

SP Wire electrode, which has a clear advantage in ultra-precision cutting processing, consists of a two-layer structure consisting of a core wire with high tensile strength and a coating with excellent conductivity. High-voltage current is almost entirely conducted through the outer layer, so the discharge performance is excellent. SP Wire electrode has the processing advantages of both tungsten wire and brass wire. The processing characteristics will vary depending on the processing conditions. The following is an example for comparison.

SP Wire – Advantages

• High tensile strength

Tensile strength has a great influence on the precision and processing speed of the workpiece. Since the core wire of SP Wire uses a special piano wire with high tensile strength, it has sufficient tensile strength for fast precision processing and reduces the problem of wire breakage.

• Fast processing speed

Due to its good electrical conductivity, it is self-evident compared to brass wire, and even compared to tungsten wire, the processing speed is greatly improved.

• Surface roughness and precision

Due to its good discharge stability and high tensile strength, surface roughness and precision achieved are equal to or better than brass wire.

• Cutting cross-sectional width

Due to its high tensile strength and stable discharge performance, the cutting cross-sectional width is narrower than that of tungsten wire and brass wire. Therefore, a sharp R angle can be processed to facilitate ultra-precision cutting.

Besides, due to the narrow cutting cross-sectional width, when performing the same precision processing, a thicker wire grade can be selected, thereby increasing the wire cutting speed.

• Wear & tear of wire feeding system

The surface of SP Wire electrode wire is soft and smooth, so the wear & tear of the wire feeding system components (power terminals, guide rails, rollers, etc.) of the discharge processing equipment will be greatly reduced compared with tungsten wire, further reducing the operating (consumables) cost.

• Automatic wire threading rate

Straightness control of the wire is excellent, which effectively improve the automatic wire threading rate.

• Surface stability

No surface oxidation and wire deterioration issues like tungsten wire, so it is easy to handle the remaining electrode wire during the discharge machining process, reducing material waste.

• HOMO phenomenon

The use of SP Wire electrode wire can effectively avoid the HOMO phenomenon caused by cutting tungsten-containing materials such as tungsten carbide with tungsten wire, and can ensure stable discharge machining performance.

• Easy to understand & setting of usage conditions

Firstly, set the processing conditions of brass wire with similar wire diameter, then gradually increase the tension and current of the electrode wire, and assess the condition of wire breakage. In this way, the most suitable processing conditions can be found. In addition, major manufacturers of EDM equipment generally prepare relevant data on SP Wire processing conditions in advance, and it is also a good idea to discuss with the equipment manufacturer.

• Bigger coil

Compared to the length of tungsten wire, which is only 3,000m~5,000m per coil, the length of SP Wire electrode wire can reach 5,000m~40,000m. This makes continuous and efficient processing possible.

• Price

Although SP Wire electrode wire has many excellent properties, its price is competitive compared to tungsten wire.

Although compared with brass wire, SP wire is higher primarily, but considering the cost savings  from faster processing speed, lesser wire breakage, reduction of your delivery leadtime & lower equipment maintenance, the long term savings are substantial.

Our partnership with the Japan manufacturer of SP Wire has been for many years; and we had successfully introduced SP Wires to many Chinese customers helping them to save cost and improve their delivery leadtime.

Now we want to share this benefit with our Asia Pacific customers too, feel free to contact me for more details.

raymond.chew@kanouprecision.com