Where Are PSU Screws Located in Your PC Case?

When building or upgrading a computer, securing the power supply unit (PSU) is crucial to the machine’s functionality and safety. The PSU is the lifeblood of the computer, converting power from the electrical outlet into usable current for other components. But, if you’ve ever found yourself ready to install a PSU only to realize you’re not quite sure about the screws, you’re not alone. It’s a common stumbling block.

Often, the appropriate screws for your PSU should be included with the product, but occasionally you might need to use the ones provided with your computer case or source them separately. As we have faced this ourselves, we know that the frustration is real. Whether it’s at a local computer hardware store or scavenging through your collection of computer spares, finding the right screw size—typically a 6-32 hexagonal head—is paramount for a secure installation.

If your PSU did not come with screws or you’ve misplaced them, it’s not a cause for panic. We can usually find these types of screws where PC components are sold or even included with the case accessories. Power supply mounting screws are standardized for most cases, but always check the compatibility with your particular case and power supply model to ensure a perfect fit and to avoid any potential damage.

Contents

1 Understanding PSU and Screws
- 1.1 Types of PSU Screws
- 1.2 Standard Sizes and Threads
2 Installation Guide
3 Compatibility and Specifications
- 3.1 PSU Models and Case Compatibility
- 3.2 Understanding Documentation
4 Additional Components and Accessories
- 4.1 Securing Expansion Cards and Drives
- 4.2 Using Zip Ties for Cable Management

Understanding PSU and Screws

It’s imperative we comprehend the two common types of screws used with power supply units (PSUs) and their respective sizes to avoid mismatches during installation.

Types of PSU Screws

When working with PSUs, we generally encounter two types of screws: 6-32 and M3. The former are hexagonal, thicker screws often used in North American PC builds, while the latter are slender and typical in European and Asian markets. It’s crucial we use the correct screws provided by the PSU manufacturer or in accordance with case specifications.

Remember:

6-32 screws have a coarser thread and are generally used for the PSU, case, and motherboard mounting points.
M3 screws feature a finer thread, suitable for securing drives or other components within the case.

Standard Sizes and Threads

The size and thread of PSU screws are pivotal for a perfect fit. Screws come in a variety of sizes, commonly measured by diameter and thread count. 6-32 screws have a thread diameter of #6 (which is roughly 0.1380 inches) and 32 threads per inch, making them thicker and more suited for securely mounting PSUs into the case.

In comparison, the M3 screws are smaller with a nominal diameter of 3 mm and fit a finer threading, tailored for components requiring precision, like SSDs and other drive bay accessories. It’s our responsibility to match the screw to the corresponding threaded hole on the PSU and the case to ensure a snug and secure fit.

Diameter	Thread	Use Case
#6 (Approx. 0.1380 inches)	32 threads per inch	PSU, case, and motherboard mounting
3 mm	Standard metric threading	Drive bays, SSDs, and other accessories

Installation Guide

When installing a power supply unit (PSU), the correct placement of screws is essential to secure the component and ensure proper operation. We will guide you through selecting the right tools, the sequence to mount your PSU, and how to verify correct alignment and resistance.

Selecting the Right Screwdriver

To start, ensure you have a Phillips-head screwdriver, which fits the standard screws used in most PSUs. The screwdriver’s size should be appropriate to the screw heads, typically #2 for PSU screws, so it grips tightly without stripping them.

Sequence of Mounting a PSU

Before we place the PSU into our rig, we prepare the screws. Typically, four screws are used to mount a PSU. Here’s the optimal sequence:

Position the PSU in the case aligning its screw holes with the case’s mounting points.
Start with the top-left screw, move to the bottom-right, then the top-right, and finish with the bottom-left screw.

This crisscross pattern ensures even pressure distribution across the PSU, which is vital for a snug fit.

Alignment and Resistance Checks

Proper alignment is crucial when mounting our PSU. Check that the screw holes on the PSU align exactly with the case’s mounting positions. You shouldn’t encounter significant resistance as you insert the screws. If you do, this might indicate a misalignment, and forcing the screw could damage the threads. We gently tighten the screws until just snug, avoiding over-tightening which can damage the PSU housing.

Compatibility and Specifications

When mounting a power supply unit (PSU) in a computer case, it’s crucial that the screws are compatible with both the PSU model and the case itself. This ensures a secure fit and prevents damage to the components.

PSU Models and Case Compatibility

We often see a range of PSU models, each potentially requiring different screw types for mounting. Typically, most PSUs fit standard ATX cases, and they use a common type of screw, which is the #6-32 UNC screw. However, this is not universal, and variations exist, especially among more compact cases or specialty PSUs designed for specific purposes like small form factor builds. We advise checking the PSU’s product specifications or the manual that comes with the PSU or the case which often lists the necessary screw type.

Understanding Documentation

It’s our responsibility to understand the documentation that accompanies both the PSU and the computer case. The documentation typically specifies the type of screws required and may provide additional information about the compatibility of the hardware. For example, if the PSU is provided without screws, the case’s manual may indicate alternative screws that can be used, as well as where they are located – often tucked away in storage compartments or attached to parts such as the HDD trays.

Additional Components and Accessories

When building or upgrading a PC, we pay close attention to the screws and accessories that secure various components in place. These often include specialized bolts and mounting screws essential for the stability and reliability of the system.

Securing Expansion Cards and Drives

For the motherboard and expansion cards like the graphics card, we use specific types of screws. Typically, a motherboard standoff and screw secure the board to the case, while thumbscrews or other provided screws fasten expansion cards into the case’s backplate. For drives, be it an HDD or a floppy drive, we generally utilize screws that may be fine-threaded or coarse-threaded based on the case’s design. Corsair cases, among others, often come with these screws, and if not, they’re readily available at hardware stores.

Using Zip Ties for Cable Management

Zip ties are our best friends when it comes to clean cable management. Not only do they help in routing cables neatly around the fan housings to avoid impedance, but they also ensure optimal airflow. When using zip ties, we make sure to not overtighten them, as they could damage the insulation of the cables. After setting up everything neatly, we replace the side panel using the panel’s securing screws, usually thumb screws for easy access.