What Size Screwdriver Bits Do You Need for PC Building?

The short version: PH2 does most of the work

Most screws in a desktop PC use a Phillips head. The common sizes are M3 and 6-32, and a Phillips #2 (PH2) bit fits both. If you own only one bit for the job, make it PH2.

The M3 and 6-32 screws turn up in many places: case side panels, motherboard standoffs, the power supply, drive trays and expansion slot brackets. That is why a single PH2 driver can build a whole system.

A magnetic tip is handy, but keep it away from nothing more than normal care. The small magnets in a driver tip are not a danger to modern PC parts. The real risk is a screw dropping onto the motherboard, so a magnetic tip usually helps more than it hurts.

Bit sizes by part

Sizes vary a little by case and brand, so treat this table as a starting point and check the screw head before you press down.

If a bit wobbles or sits loosely in the screw head, it is the wrong size. A loose fit is the most common reason a screw head gets chewed up.

Why the small sizes matter

The M.2 screw is the one that surprises first-time builders. It is tiny, it sits right next to the board surface, and a PH2 bit is usually too large for it. A PH0 or PH1 bit fits better and gives you control.

Some cases and coolers also use hex or Torx heads. You may not need them, but they are cheap to have in a kit and save you from improvising with the wrong tool.

Long bits are worth having too. Screws sit deep inside some cases, and a longer shaft lets you reach them without your hand crowding the parts around them.

Do you need an electric screwdriver?

No. A basic manual PH2 screwdriver can build an entire PC. An electric precision driver makes the repetitive screws faster and easier on your wrist, but it is a convenience, not a requirement.

The catch is torque. Motherboard and M.2 screws strip easily and a board can crack if you overtighten. Our electric screwdriver for PC building comparison suggests looking for an electric setting under about 0.5 N·m. Household drivers can start at several N·m, which is far too much for delicate parts.

Here is how a few of the PC-friendly drivers on that page compare, using the published specifications:

• JAKEMY 3-torque kit: 0.12 to 0.3 N·m across three settings, with 160 bits included.
• STREBITO 155-in-1: three gears at 0.15, 0.35 and 0.5 N·m, with 140 bits, an LED light and a 650mAh battery.
• STREBITO 144-piece: five settings from 0.15 to 0.7 N·m, with 120 bits.

What to look for in a bit set

Bit counts in kits look impressive, but a PC build uses only a handful of them. What matters is that the set includes the sizes you need and that the bits fit snugly.

A short checklist helps when you compare kits:

• Phillips PH0, PH1 and PH2 bits, which cover nearly every Phillips screw in a PC.
• A few hex and Torx bits for coolers, fans and some cases.
• At least one long bit for recessed screws.
• A magnetic tip so screws stay on the driver.
• A labeled case or holder so small bits do not get lost.
• A manual mode or a separate hand driver for loosening stuck case screws.

A simple bit order for your build

You do not need to swap bits constantly. Most builders use PH2 for nearly the whole job and change bits only for a few steps. You can see more kit options on our PC building screwdriver comparison page if you want to pick a set before you start.

• Open the case with PH2, or by hand if it uses thumbscrews.
• Install motherboard standoffs if needed, using PH2 or a hex bit.
• Mount the motherboard with PH2, tightening each screw until snug and no further.
• Fit the M.2 drive with PH0 or PH1.
• Secure the power supply and graphics card bracket with PH2.
• Mount the cooler and fans with whichever bit the hardware calls for.
• Close the panels with PH2 and check that nothing rattles.

Safety notes

Unplug the power cable and switch off the power supply before you put a tool inside the case. Never work on a PC that is plugged in and running.

Touch bare metal on the case to discharge static before handling parts, and avoid working on thick carpet. Keep screws and loose bits out of the case when you power on, since a stray metal screw can short a board.

If you use a power driver, start on the lowest torque setting and stop as soon as the screw feels snug. Wear safety glasses if you are cutting zip ties or snapping off plastic tabs, since small pieces can fly.

Frequently asked questions

Can I use a magnetic screwdriver inside a PC?

Yes. The magnets in a driver tip are weak and will not harm modern components. The bigger risk is dropping a screw onto the board, which a magnetic tip helps prevent.

Is a PH1 bit better than PH2 for PC building?

PH2 suits most screws, while PH1 is a better fit for smaller screws such as some drive and M.2 fasteners. Having both is the safest choice.

Do I need a torque screwdriver for a PC build?

It is not required, but a low-torque electric setting helps prevent stripped threads and cracked boards. If you work by hand, simply stop turning once the screw is snug.

What if a screw head is already stripped?

Try a slightly different bit size that grips the damaged head, apply gentle downward pressure and turn slowly. If it will not move, switch to a manual driver for better feel rather than forcing it.