Cold Heading Tolerances and Technical Data
Geometries
There are geometric limitations to parts that can be cold formed. Above are some sketches of parts showing features that can and cannot be cold formed.
The drawing to the right has some features that can be put on by typical secondary operations. Typical cold formed tolerances are shown on the diagrams. Tighter tolerances can be held if needed.
Material for Cold Forming
This a list (admittedly incomplete) of metals suitable for cold forming, and some that are not. A general guideline for cold formability is that the metal’s elongation must be at least 20%.
View Properties Table
|
Suitable Alloy |
Cold Formability Characteristic |
|
Copper |
Excellent |
|
Gold, Silver and most of their Alloys |
Excellent |
|
Brass- Cartridge Brass |
Good |
|
Platinum, palladium, tantalum, and their alloys |
Most are cold formable. |
|
Titanium and its alloys |
Pure Ti and alloys with high ductility, yes, but alloys like 6-4 are only hot headable. |
|
Nickel and its alloys |
Pure Ni yes, alloys with room temperature elongation of 20% or more, yes. |
|
Iron and steels |
Pure iron, yes. Steels, depends on the steel. Many are cold formable. |
|
Non-Suitable Alloy |
Cold Formability Characteristic |
|
Brass-free machining grades (like C360) |
Poor- chip-breaking additives promote cracking. Use instead 260 brass. |
|
Cast iron |
Too brittle |
|
Silicon |
Too brittle |
|
Tungsten |
Too brittle |
|
Cobalt and cobalt alloys |
Generally too brittle |
|
Rhenium |
Too brittle |
|
Rhodium |
Mostly too brittle |
Useful Links
www.copper.org Copper Development Association
www.onlineconversion.org Conversions from anything to anything else
www.engineersedge.com Engineering Reference Directory
