Product Review

✔  Screw head style: button ; Screw drive style: hex socket, known as internal hex drives
✔  10.9 grade alloy steel, Hardness: HRC 32-39
✔  Rust proof: black oxide finish and anti-rust oil covering
✔  Easy to store: these screws come in an easy-use storage case

Item-----------Thread Length---------Total Length
M6 x 8 ----------8mm/0.31"-----------11.2mm/0.44
M6 x 10 --------10mm/0.39"----------13.2mm/0.52"
M6 x 12 --------12mm/0.47"----------15.2mm/0.60"
M6 x 16 --------16mm/0.63"----------19.2mm/0.76"
M6 x 20 --------20mm/0.79"----------23.2mm/0.92"

Package Contains:
M6 x 8--------10 Pcs
M6 x 10-------10 Pcs
M6 x 12-------10 Pcs
M6 x 16-------10 Pcs
M6 x 20-------10 Pcs
Total: 50 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 Button Head
 Button head is similar to standard pan head but have a curved top