Cold Heading
What is Cold Heading
Cold heading manufacturing is a multi-step process used to form metal parts at room temperature. Unlike other metal fabrication processes, hammers and dies are used at a high speed to form the metal without heating the material.
A large coil of wire is fed into a blank and pulled through a drawing machine. The drawing machine compresses the material to the desired diameter. It then passes into the cold heading machine.
Inside the cold heading machine, the blank is hit between a die and a punch block, pushing the material into the die to create the desired shape.
We use two separate techniques for forcing the material into the die. With the upset method, the punch block forces the metal out of the die to produce a head larger than the initial blank.
The extrusion technique includes two methods, forward and backward extrusion. With forward extrusion, the cavity of the two dies is smaller compared to the diameter of the wire, which creates compression. With backward extrusion, the metal is forced backward through a punch to create a hole or cavity.
Cold heading is commonly used for creating custom screws, bolts, and other custom fasteners out of round metal stock.
When should you choose cold heading for your parts?
Cold forming comes with advantages and disadvantages compared to other machining processes, such as screw machining.
While using a screw machine may eliminate the need for dies, cold forming requires dies to set the head shapes, which increases the lead time and initial cost. However, cold heading includes many benefits:
- Less waste
- Faster production
- Stronger parts
- Reduced costs
Using cold heading for your parts reduces material waste. More of the material is utilized during the cold forming process. This limits scrap and overall costs.
Advantages of Cold heading
Because the volume of the blank is being hammered into a die and there is no cutting required, the process has little or no scrap. Cold heading creates stronger pieces much more efficiently. In addition, because no heat is required, there is less environmental impact, and workers are provided with a safer environment. The production is fast with no cooling down process required and creates pieces with closer tolerances without secondary operations.
Disadvantages of Cold Heading
Without heat, the pieces must be created with more force. While dies may be cheaper, the machinery required is bigger and more expensive. The pieces cannot be as thick as they may in machining because hammers can only force so much metal into a given space. Harder metals can require multiple blows to fill a die and certain materials cannot be used in a cold heading machine at all. More complex pieces will require secondary operations as cold heading machines cannot perform operations like rolling, stamping, or bending.
Cold Heading Applications
Cold heading has typically been used to create pieces like simple fasteners, though with technology always improving, cold heading can be used to create highly specialized fasteners and specialty pieces. This includes fasteners used in bridges, automotive manufacturing, electronics, and specialty bolts.
Chengdu JINGBANG Cold Heading Capabilities
Our equipment ranges from your average 2 die/2 blow all the way to the most advanced 5 die/5 blow machines available. We utilize a wide range of materials such as Steel, Stainless, Alloy, Brass, Bronze, Copper, Inconel, 17-4ph, exotics, and specially blended materials.
A shortlist of our strengths are automotive components, gear blanks, ball studs, piston pins, sparkplug shells, valve spring retainers, engine poppet valves (intake and exhaust), transmission shafts, agricultural parts, bearings, screws, bolts, nuts, specialty and per print items.