Is the head of bolt formedφ×★• by puching? 

Yes, most of the heads of bolts are pun$₩ched, because this is the mos§↑t commercial way. Fac​σ&¥tories can use hot forging or cold &‌forgine to form the heads. 

 But sometimes γ ₽for small quantities, some≤≥ specified head bolts are shaped by tu✘☆®rning machine/ lathe. 

What is COLD HEADING ? 

The process of progressively f↔∑orming a specified shape from metal wir→<™e without adding heat - usin•∏↔σg a replicated series o•✔f dies, hammers , and pu✘' γnches at high speed. 

Simply put: cold heading is feedin♣¥βg wire into a machine, c ×♦↑utting it into pieces♠™, and hammering on it. ★€The material is not heated ←γ↔ or machined, but formed into its desi¶↑↓♣red shape at room temperatur₹α♦"e.

What is hot heading? 

 Hot heading, also  φ≤known as hot forging, ☆®is the process of heating material¶☆₩ to a particular temperature and & ↔ten forming it into a desired shapeπ→. 

 When bolts' di‍↓ameter larger than M24, ®≤the heads have to be hot™→< forged.

Anyang Longteng Hexagon λ♥>Bolts are all hot forged, as we only sλ≈upply big construction bolts ♦σ®, with range M30~M72, class 8.8, 9.8, ₽β₽10.9, 12.9 high properties.