Product Review

✔ Meets/Exceeds: DIN912
✔ 12.9 alloy steel, hardness: HRC 39-44, tensile strength 1220 N/mm²
✔ Screw Head: socket cap; screw drive: hex socket, known as internal hex drives
✔ Rust proof : black oxide finish, covered with anti-rust oil
✔ These screws come in an easy-use separated girds storage box

Item---------------Thread Length------------Total Length
M6 x 35mm--------------35mm/1.38"--------------41mm/1.61"
M6 x 40mm--------------40mm/1.57"--------------46mm/1.81"
M6 x 45mm--------------45mm/1.77"--------------51mm/2.01"
M6 x 50mm--------------50mm/1.97"--------------56mm/2.22"
M6 x 55mm--------------55mm/2.17"--------------61mm/2.42"

Package Contains:
M6 x 35mm------------4 Pcs
M6 x 40mm------------4 Pcs
M6 x 45mm------------4 Pcs
M6 x 50mm------------4 Pcs
M6 x 55mm------------4 Pcs
Total : 20 Pcs

About Hex Socket Drives:
  Hex socket drives, also known as internal hex drives, have a hexagonal hole in the center that requires an Allen key, also known as a hex key or Allen wrench
About Socket Cap Head:
  Socket cap head screws, also known as Allen head screws, have a recessed drive, and are commonly used when there is not enough clearance for a conventional wrench or socket. They are fastened with an Allen wrench, which is also called a hex wrench or hex key