head hardness HRC54-57, carburizing process.
Threaded portion: HRC30-40;
Process for subzero treatment and thermal aging treatment, improves the precision and stability of size;
Tensile test every batch: 30 pull stud can be up to 12 tons, 40 pull stud can be up to 15 tons, 50 pull stud up to 20 tons;
Surface coating processing, improve the surface hardness, wear resistance, improve the cleanliness, precision is more stable, more smooth surface, anti-rust, anti-corrosion effect is better, feel more comfortable, more beautiful appearance.
