SODIAL(R) 50 PCS Quadrex Head Short Computer Case Motherboard Screws Quadrex Head Motherboard Screws in packs of 50 to be used for PC computer cases motherboards PCI cards etc. These screws are made of iron material. ROM CDROM Screws are standard course thread. Each screw size: 9mm(L) x 3mm(diameter) Head diameter: 6mm