Wire drawing dies are tools with highly polished, specially shaped holes through which wire is drawn to reduce its diameter. They have a metal case and a nib made of carbide, polycrystalline diamond (PCD), or natural diamond. When selecting wire drawing dies, wire material and drawing parameters are important specifications to consider. Typically, wire materials include:
- stainless steel
- aluminum alloy steel
- galvanized high-carbon steel
- stainless steel
- low-carbon steel
Drawing parameters include measurements such as inlet diameter, bell radius, entrance angle, approach angle, bearing, and back relief. Elongation, the ratio of length after drawing to the length prior to drawing, is also an important consideration when choosing wire drawing dies.
There are many different types of wire drawing dies. Examples include standard wire drawing dies, PCD wire drawing dies, and TC wire drawing dies. Standard wire drawing dies have a well-defined reduction angle that reduces drawing force and provides uniform die formation with a consistent surface finish. PCD wire drawing dies use polycrystalline diamond (PCD), a synthetic material that provides superior resistance to cracking and wear. TC wire drawing dies are made from tungsten carbide, an extremely hard and scratch-resistant material that is often used in tool bits.
Tungsten carbide Dies: Versatile and commonly used for drawing various materials including steel, copper, aluminum, and other non-ferrous metals. They provide good wear resistance and are cost-effective for general wire drawing applications
Polycrystalline Diamond (PCD) Dies: PCD dies are made from synthetic diamond particles sintered together under high pressure and temperature. They offer high wear resistance and are suitable for drawing hard and abrasive materials like stainless steel, tungsten, or high-carbon steel wires.
Natural Diamond Dies: Made from natural diamond crystals, these dies are known for their exceptional hardness and durability. They are used for drawing fine wires and in applications where extreme precision and surface finish are required.
Wire drawing dies are used with a variety of wire drawing tools and equipment. Pull-in dogs are used to grip a wire’s end as it enters the die. After the pull-in dog is fastened to the block, the wire is drawn through the die. Wire drawing dies are also used with both single-block and multiple-block machines. With single-block equipment, the wire passes through a die and collects on a standard block.
With multiple-block machines, the wire is pulled through a die and wrapped around a slightly tapered block. The wire then moves upward onto collector pins and exits the upper section to reduce back tension. Typically, inverted drawing machines or gravity blocks are used with coarser wire sizes, or to draw wire that requires superior surface quality. Wire drawing dies for these machines are available from a variety of suppliers.
Lubrication in the drawing process is essential for maintaining a good surface finish and long die life. Various lubricants, such as oil, are employed. The following are different methods of lubrication:
Wet drawing: the dies and wire or rod are completely immersed in lubricants
Dry drawing: the wire or rod passes through a container of lubricant which coats the surface of the wire or rod
Metal coating: the wire or rod is coated with a soft metal which acts as a solid lubricant
Ultrasonic vibration: the dies and mandrels are vibrated, which helps to reduce forces and allow larger reductions per pass.
The selection of wire drawing dies depends on various factors, including the material to be drawn, wire diameter, required tolerances, surface finish, production volume, and cost considerations. Each type of die offers specific advantages that cater to different industrial requirements.
ZHUZHOU UKO CARBIDE has 14 years experience of in production and export in the wire industry. It has broken away from the single sales model to providing complete solutions for the wire drawing industry. UKO will continue to achieve breakthroughs in high-end products with higher technology to help customers gain new competition, and pursue to become an industry leader in segmented fields.