The Beginner’s Guide to Drawing Dies
As one of the indispensable wire drawing tools, there are various of drawing dies. Only distinguish correctly and choose suitable drawing dies, wire manufacturers can produce high quality wires.This article will introduce detailed matters about drawing dies for you.
What Are Drawing Dies
Drawing dies are one of the traditional dies used to draw many kinds of wires and tubes.Pressed by the deformation part of the drawing dies, inner metal instruction of the wires/tubes was changed from the original diameters to smaller diameters. A group of drawing dies work together to produce a designated smaller diameter wire/tube with a predictable surface.
Common Types of Drawing Dies
Here introduce the categories of the drawing dies for you as follows,
Applications:
According to application, drawing dies can be divided to wire drawing dies and tube drawing dies.
1.Wire drawing dies’ diameters are usually smaller from 0.1mm-5.0mm with high demand.
2.Tube drawing dies’ diameters are usually bigger from 6.0mm-80.0mm with comparatively low demand.
Above mentioned is general from diameters.The real circumstance may be different according to your wires and tubes sizes.
Materials:
According to raw materials of drawing dies,there are diamond drawing dies,tungsten carbide drawing dies and nano diamond drawing dies.
1.Diamond Drawing Dies
Diamond drawing dies is a kind of drawing dies with good performance price.Wires made by diamond drawing dies always have good surface.From the origin of diamond, there are natural diamond drawing dies and synthetic diamond drawing dies. The former was made by natural diamonds with smaller diameter 0.05mm-2.00mm .The later with general diameters 0.1mm-30.0mm, are made by synthetic diamonds.
2.Tungsten Carbide Drawing Dies
Tungsten carbide dies are widely used because their low cost and wide diameter range from 0.5mm to 80.0mm.While the wire surface made by them are not so good as that made by diamond drawing dies.
3.Nano Diamond Drawing Dies
Nano diamond drawing dies combine the advantages of diamond drawing dies and tungsten carbide drawing dies.But it will take longer time to produce nano diamond drawing dies and they can not be repaired.
Shapes：
According to the inner hole shapes, there are common round wire drawing dies and shaped wire drawing dies, which include regular square,rectangular,oval,triangle etc. and some irregular shapes. Customized shapes are available.
Design of Drawing Dies
Parameters mentioned here are all very important to wire drawing dies.Any mistakes of these parameters will affect the dies’ performance and finally affect wire quality.The parameters should be reasonable and suitable for real production circumstance. This can be realized by many years’ production experience.
Appearance of Drawing Dies
You need to pay attention to following parameters of appearance of drawing dies.
1.Generally made by stainless steel,cases support and protect drawing dies.The cases are usually cylinder which need customers to provide diameters and thickness.According to different wire drawing machines,customers may need some cases with angles, say 3° ,5°。
2.Specifications of cases include diameter, thickness,entrance and exit diameters,tolerance and so on.Some customers many request bigger entrance and exit to make the wires pass through easily.
Inner Geometry of Drawing Dies
Inner geometry critical because it is drawing dies’ working area.Its reasonability decide directly the wire drawing result. Generally speaking, inner geometry include following specifications,
1. Entrance angle needs to be big for wires passing.
2.Lubricant part is transition area of entrance and reduction parts.It needs to be well blended to avoid scratching wires.
3.Reduction part are transforming part of wires. The wire diameter start to become smaller here.
4.Bearing part make the final wire diameter to be designated size .
5.Exit angle should be bigger for wire coming out.
Drawing Dies Matching
Dies matching is also an important part to decide your drawing machine work well to get required wire diameters。When match dies, following points need to be considered,
1.Parameters of drawing machine decide the quantity and reduction ratio of drawing dies.
2.Reduction ratio decides the interval of each drawing die.
3.Lubricating method: powder or oil lubricant.
4.Drawing speed.
Production Processes of Drawing Dies
There are usually following production crafts to make drawing dies.Only control each craft strictly can produce high quality dies. When select drawing dies, you can judge the quality from these aspects,
Casing:
Put the blanks into a case with sintering powder then heat it under a high temperature. After cooling, the blanks had been one unit with cases.Drawing dies manufacturers with rich experience can control the sintering temperature well to ensure the case support the dies well.
Drilling Hole：
Laser drilling can get a general geometry of the inner hole. Advanced laser drilling machines can drill the hole quickly and efficiently so the lead time of drawing dies can also be shortened to improve your wire production efficiency.
Refurbish:
The holes will be refurbished further to get an exact geometry.
Polish:
The ultrasonic machines will polish the inner hole to be like mirror, especially reduction and bearing parts. Excellent polishing can not only extent the drawing die’s life time, your wires surface and quality can also be ensured.
Inspect:
Machine inspecting and wire inspecting are normally used methods to check the dies. Inspecting machine can check every specification of drawing dies.Conoptica is one of the usually used inspecting machines.
Drawing Dies for Different Materials
Parameters of drawing dies are different according to different drawing materials as follows,
Nonferrous Materials:
Common nonferrous wires are copper, aluminium, gold, silver etc., which are comparatively softer. When design the drawing dies, reduction angle can be about 16°-18°. Considering production cost,the blanks can be unsupported.
Ferrous Materials:
High carbon wires, low carbon wires, stainless steel and high speed steel wires are all ferrous wires, which are very hard. Reduction angle of drawing dies can be 12°-14°. Drawing power for these hard wires are bigger so tungsten carbide supported blanks are better.
Special Materials:
Besides above mentioned wires, there are also some special wires. You can choose suitable drawing dies to process them.
Common Problems in Wire Drawing Process
According to our rich experience,following problems may happen in wire drawing process for your reference,
1.The Drawing Machine Can Not Work
Except the problems of the machine, this situation is usually caused by the not reasonably designed parameters of the drawing dies, which make the group of dies not cooperate with each other to finish the drawing process. At this time, it is necessary to redesign or modify some parameters of the dies.
2.Wire Breaking Problems
It may caused by small lubricant area or big reduction ration of drawing dies.You can enlarge the lubricant area or decrease the reduction ratio between the drawing dies.
3.Scratching on Wire Surface
The scratch are usually made by a not well polished part, for example, reduction part.You can check the inner hole and repolish it.Moreover, too small reduction angle can also make scratches on wires.
4.Not Good Wire Surface
Wire surface connects closely with the wire blanks’ grain size. If you want excellent wire surface,blanks with fine grain sizes are better choice, say 1 micron,3 micron,5 micron etc..
Which Factors Decide the Drawing Dies’ Life Time?
Drawing dies are precise dies, whose performance will be affected by raw materials,production crafts, parameters design or production circumstance.So only controlling each process can get perfect drawing dies for wires.
Materils:
Raw materials affect much on drawing dies.Wire blanks with even inner structure and high consistency are your first choice.You can also choose suitable sizes and grain sizes according to the wires.
Production Crafts:
Production crafts decide the stability of the drawing dies. Casing,drilling, refurbishing, polishing and inspecting should all be controlled to ensure the drawing dies quality.
Profile Design:
Every parameter of the inner hole must be designed reasonably to make the drawing dies work well.Especially reduction and bearing, as transforming part and diameter forming parts, they are crucial to the drawing dies.
Drawing Circumstance:
Drawing circumstance, mode, power, drawing speed and lubricating methods will all affect wire drawing results.
Maintenance of Drawing Dies
To help customers reduce production costs, some drawing dies can be repaired for 2 or more times. After inspecting the used dies and confirming the damage is not severe an, the dies can be refurbished, enlarged holes, and repolished for reuse. If the die blanks are big enough, some dies can even be repaired for several times.
This article introduces you to the relevant knowledge of wire drawing dies from the aspects of category, design, production process, and maintenance. We HG Super Hard Tools are committed to producing various high-quality wire drawing dies. With over 20 years of production experience and strong technical support, we can solve all problems in the wire drawing process for you. If you have any demand for wire drawing dies, please feel free to contact. We will serve you sincerely!
FAQ
1.How to choose suitable drawing dies？
You can choose drawing dies according to the drawing machine and wires.The former decide the dies quantity and case sizes and the later decide which kind of drawing dies can be used.
2.All drawing dies can be repaired?
Not always.Some dies had been destroyed severely in wire drawing process.If the reduction parts or other working parts were worn out, the dies can not be repaired.
3.Is drawing dies repairing service free of charge?
It’s upon your purchasing quantity. If annual quantity reaches to a certain number, free of charge repairing can be considered.
4.Which drawing dies are you deal in now?
At present we mainly manufacture PCD dies,natural diamond dies,single crystal diamond dies and some tungsten carbide dies.
5.Are customized drawing dies available？Is there any requirements on the quantity of customized drawing dies?
Yes,customized drawing dies are no problems.We are able to manufacture the dies according to your requirements.As for quantity,there is MOQ for tungsten carbide dies because when purchase tungsten carbide, there is also MOQ for us.You can inquiry the MOQ based on the dies you need.