Fully threaded rods (all-thread) are manufactured by selecting high-strength steel (carbon, stainless), followed by straightening and cutting to length. Threads are created primarily via cold rolling (high efficiency, high strength) or cutting, followed by optional surface treatments like galvanizing (zinc coating) for corrosion resistance. The process ensures uniform threads along the entire length.Key Product Processing Steps:
* Raw Material Selection: Common materials include low carbon steel, alloy steel (ASTM A193 B7), or stainless steel for high-load or corrosive environments.
* Straightening: Raw steel coils are straightened before threading to ensure axial alignment.
* Threading Method:
* Thread Rolling (Common): Cold-forging process where hardened dies press into the steel, displacing material to form threads without cutting. This creates higher fatigue strength.
* Thread Cutting: Cutting into the metal, usually for larger diameters or special projects.
* Cutting to Length: Rods are produced in long lengths (e.g., 1–3 meters) and cut down to standard sizes like 1-foot or 6-foot,or custom lengths.
* Chamfering: Ends are beveled to allow for smooth installation of nuts and prevent damaged thread entry.
* Surface Treatment/Finishing:
* Plain Finish: Oiled or untreated.
* Zinc Plating: For corrosion resistance in dry environments.
* Hot-Dip Galvanizing (HDG): Heavy coating for outdoor/coastal applications, often requiring centrifugal spinning to ensure threads are not blocked by excess zinc