1/10pc M3 M4 M5 M6 M8 Black Grade 12.9 Steel Lengthened Long Allen Hexagon Hex Socket Cap Head Screw Bolt Half Thread L=30-300mm(300MM_M8 10PCS)

1.Material SelectionCarefully selected grade12.9 carbon steel for superior durability 2.Cold heading moldingAdopting efficient cold heading molding process, the grade 12.9 carbon steel material is accurately transformed into Lengthened Hexagon Hex Socket Cap Head Half Thread Screw Bolt 3.Hexagon Hex Socket Cap HeadEnsure the precision and reliability of the hexagon structure through professional cap head design 4.Heat treatmentHeat treatment is carried out to enhance the hardness and strength of the screws 5.Polishing treatmentAfter polishing treatment, make the product surface smoother and enhance the appearance of texture