Pc Case Screw Size: A General Guide

Computer case screws are the hardware used to secure parts of a PC to its case. While there are many computer case manufacturers, they generally use three thread sizes: the Unified Thread Standard (UTS), which originates from the United States, and the ISO metric screw thread, which is standardised worldwide. The third is the M3 screw, which is thinner than the #6-32 UNC and #4-40 UNC screws used in the UTS.

#6-32 UNC screws for 3.5 hard disk drives

#6-32 UNC screws are commonly used to fasten 3.5" hard disk drives to the case of a PC. They are also used to secure the covers of the case and to hold expansion cards in place. These screws are typically made of steel and feature a nickel-plated finish.

The #6-32 UNC screw is a UTS (Unified Thread Standard) screw, which originates from the United States. It has a major thread diameter of #6, which is defined as 3.51 mm or 0.1380 inches, and 32 threads per inch (tpi), resulting in a thread pitch of 0.7938 mm or 0.031250 inches. The "UNC" specification indicates that it uses a standard coarse thread, although this is considered redundant as "32" already denotes a coarse thread.

The most common lengths for #6-32 UNC screws are 3/16 inches (4.76 mm) and 1/4 inches (6.4 mm), although they can also be found in less common lengths such as 5/16 inches (7.94 mm) or non-standard metricized lengths like 5 mm (0.20 inches).

When purchasing #6-32 UNC screws for 3.5" hard disk drives, it is important to ensure that the thread size matches the drive's requirements. The thread size of #6-32 UNC screws is M3.5 or 3.5 mm, which is suitable for 3.5" HDDs.

These screws typically feature a Phillips drive, although they may also be found with a Green Robertson or Torx drive. The head style of #6-32 UNC screws can vary, with flat, pan, and hex heads being common options. Flat-head screws have a flat top that sits flush with the surface, while pan heads have a low disk shape with a chamfered outer edge. Hex heads, also known as Allen heads, feature a hexagonal recess that requires an Allen key or hex key for tightening and loosening.

When shopping for #6-32 UNC screws, it is important to consider the quantity needed for your project. They are commonly available in packs of 50, 100, 200, and 400.

In addition to the screw size and quantity, the material and finish of the screws are also important considerations. As mentioned earlier, #6-32 UNC screws are typically made of steel and feature a nickel-plated finish. This finish provides corrosion resistance and a decorative appearance.

When assembling or disassembling PC cases, it is essential to handle the screws with care to avoid cross-threading or stripping the threads. Properly sized tools should be used to tighten and loosen the screws, ensuring that they are not overtightened, which can damage the threads or the material into which the screw is threaded.

M3 screws for 5.25 optical disc drives

M3 screws are commonly used to secure 5.25-inch optical disc drives to a PC case. The M3 screw is a metric screw with a nominal diameter of 3 millimetres (0.12 inches) and a standard coarse thread pitch of 0.5 millimetres (0.02 inches).

M3 screws are the second most common type of screw found in PCs, after the #6-32 UNC screw. They are typically used to secure a range of devices, including optical disc drives, 2.5-inch hard disks and solid-state drives, and 3.5-inch floppy drives. They are also used for motherboard standoffs, which provide a margin of space between the motherboard and the case to prevent short circuits.

M3 screws are available in a variety of lengths, typically ranging from 1 to 20 millimetres. They usually accept a #2 Phillips screwdriver tip, although a Green Robertson or Torx drive may also be used.

When purchasing M3 screws for 5.25-inch optical disc drives, it is important to ensure that the screws are short enough to fit the drive and case.

#4-40 UNC thumb screws for DVI, VGA, serial and parallel connectors

#4-40 UNC thumb screws are commonly used to secure DVI, VGA, serial, and parallel connectors. These connectors are typically found on computer cables, such as monitor cables. The screws help to prevent connectors from falling out, which was particularly important for older, heavier connections.

#4-40 UNC thumb screws are available in packs of 10 or 30 from various retailers. They are usually made of stainless steel and measure 47mm in length.

In addition to the thumb screws, plastic grips may be used to allow for easy and fast assembly.

#6-32 UNC screws for power supply

#6-32 UNC screws are used for securing a power supply to a PC case. They are also used for 3.5-inch hard disk drives, expansion cards, and case panels.

The #6-32 UNC is a UTS (Unified Thread Standard) screw, which originates from the United States. The diameter of the screw is 0.1380 inches (3.51 mm), and it has 32 threads per inch (tpi), resulting in a thread pitch of 0.031250 inches (0.7938 mm). The UNC specification indicates that a standard coarse thread is used. It is typically provided with a #2 Phillips drive and a 1/4-inch (6.4 mm) flanged hex head.

The #6-32 UNC screw is commonly used in computers due to its compatibility with various components. It is typically available in lengths of 3/16 inch (4.76 mm) and 1/4 inch (6.4 mm), although other lengths such as 5/16 inch (7.94 mm) and 5 millimetres (0.20 inches) can also be found.

When purchasing a new PC case, it is common to receive a bag of #6-32 UNC screws, along with other types of screws and small components. It is important to identify the correct type of screw for each application to avoid damage to the computer components.

In addition to the #6-32 UNC screws, there are two other common thread types used in PC cases: the self-tapping screw for fans and ventilation-related parts, and the M3x0.5 standard screw for optical drives, floppy disk drives, and motherboards.

M3 screws for 2.5 hard disks and solid-state drives

M3 screws are used for mounting 2.5-inch hard disks and solid-state drives (SSDs) in computers. They are the second most common type of screw found in PCs, after the #6-32 UNC screw. The M3 screw has a nominal diameter of 3 millimetres and a standard coarse thread pitch of 0.5 millimetres.

M3 screws are typically used to secure the following devices:

• 5.25-inch optical disc drives
• 2.5-inch hard disks and solid-state drives
• 3.5-inch floppy drives

M3 screws are also used as motherboard standoffs, which provide a margin of space between the motherboard and the case to prevent short-circuiting.

When it comes to 2.5-inch hard drives and SSDs, M3 screws are often used in conjunction with a mounting tray or caddy. These trays or caddies allow the drive to be securely fastened and mounted in the computer case.

The length of M3 screws can vary depending on the specific application. For example, M3 screws used for 2.5-inch drives typically have a length of 4mm, 4.7mm, 4.8mm, or 5mm. It is important to use the correct length screw to ensure a secure fit and avoid any damage to the drive or surrounding components.

In addition to the screw length, the head type of the screw is also an important consideration. Common head types for M3 screws include flat head, countersunk, and pan head. The type of drive is also a factor, with Phillips and Torx drives being commonly used for M3 screws.

When purchasing M3 screws for 2.5-inch hard disks and solid-state drives, it is important to ensure compatibility with your specific drive and computer case. While M3 screws are a standard size, there may be variations in the length and head type required for your particular setup.

Overall, M3 screws play a crucial role in securely mounting 2.5-inch hard disks and solid-state drives in computers, ensuring stable and reliable performance.

Frequently asked questions