Computer case screws are the hardware used to secure parts of a PC to the case. Although there are numerous manufacturers of computer cases, they have generally used three thread sizes. The Unified Thread Standard (UTS) originates from the United States, while the ISO metric screw thread is standardized worldwide. In turn, these thread standards define preferred size combinations that are based on generic units—some on the inch and others on the millimetre.
From left to right: a #6-32 UNC thumbscrew, a #6-32 UNC screw, an M3 screw and a self-tapping screw for case fans
Various types of motherboard standoffs
A male DE-9 connector showing hex jackposts on either side of the D-shell. Note the limited clearance.
Close-up of a #6-32 UNC screw with a flanged hex/Phillips head, commonly provided in PC cases
A computer case, also known as a computer chassis, is the enclosure that contains most of the hardware of a personal computer. The components housed inside the case are referred as the internal hardware, while hardware outside the case are known as peripherals.
An ATX case. The motherboard (microATX) is in a horizontal position at the top, and the peripheral connectors go at the panel located at the rear of the case and USB ports at the top. The fans are also at the rear and front. The power supply is on the bottom rear.
A full tower case. Accessories shown include: a fan controller, a DVD burner, and a USB memory card reader.
An empty computer case
Interior of a 2018 ATX computer tower
