✔ Meets/exceeds: ISO7380
✔ Screw Head Style: Button, Screw Drive Style: Internal Hex, Hex Size 2.5 mm, known as Hex Socket Drives
✔ Screws Head Diameter : 7.4 mm; Screws Head Height: 2 mm; Thread Size( Dia. ):4 mm;Thread Pitch :0.7 mm
✔ Nuts outside hex sizes: 6.8mm/0.27", nuts height ( thickness ): 3.1mm/0.12"

[ Sizes ]---[ Thread Length ]----[ Total Length ]
M4 x 6 ------6mm/0.24"------8mm/0.31"
M4 x 8 ------8mm/0.31"------10mm/0.39"
M4 x 10 -----10mm/0.39"-----12mm/0.47"
M4 x 12 -----12mm/0.47"-----12mm/0.55"
M4 x 16 -----16mm/0.63"-----18mm/0.71"
M4 x 20 -----20mm/0.79"-----22mm/0.87"
M4 x 25 -----25mm/0.98"-----27mm/1.07"
M4 x 30 -----30mm/1.18"-----32mm/1.26"

[ Package Contains ]
M4 x 6-----25 Pcs
M4 x 8-----25 Pcs
M4 x 10----25 Pcs
M4 x 12----25 Pcs
M4 x 14----25 Pcs
M4 x 16----25 Pcs
M4 x 20----25 Pcs
M4 x 25----25 Pcs
M4 x 30----25 Pcs

M4 Hex Nuts-------225 Pcs
Hex Key -------1 Pcs

[ About Internal Hex Drives ]
Internal Hex Drives, also known as Hex Socket 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 screws are similar to standard pan head screws, but have a curved top