B type (carburizing and quenching common pull stud)
Technology: High-quality low-carbon alloy steel carburizing and quenching, hard externally and soft internally, excellent resistance to impacts. Moderate price.
A type(carburizing and quenching high quality product pull stud)
Technology: High quality low carbon alloy steel processing thread after carburizing and quenching; the holder with high hardness (Resistance to wear and long service life); the thread with slightly low hardness (contributing to protecting the thread of tool holder); the core with the lowest hardness (resistance to shock ), accurate dimensions and applicable for high-end tool holder.
N type(high quality material competitive pull stud)
Technology: Hiqh quality low carbon alloy steel 20CrNiMo(SNCM220),excellent resistance and tensile stress,rust resistance is much better.
HRC53-57(40#-60#)
Some inventories are subject to:HRC51-55(15#-30#)