M3 x 4mm screws — what they fit & where to buy

the SFF-8201 standard: four M3 side holes, plus two optional bottom holes on 7mm drives

3-4mm side (short, so it can't touch the PCB) · confirmed · source

drive bays, laptop caddies and SSD brackets

3-5mm · confirmed · source

M3 for 2.5in SSD side mounting; 3.5in bays are tool-less or 6-32

3-4mm · confirmed · source

ATX boards thread into brass standoffs with M3 machine screws

3-5mm, thin flat/pan head · confirmed · source

bezel and mounting bracket screws, unlike desktop 5.25in bays

3-4mm · reported · source

many redesign around M3 standoffs for easier sourcing (the board itself is M2.5)

4-6mm screws with 6-11mm standoffs · reported · source

heater block clamp, fan shroud, and headless grub screws

3-4mm grub, 6-10mm shroud · confirmed · source

internal cage assembly screws — the tripod-facing ports are 1/4-20, not M3

4-8mm · confirmed · source

PCB-to-chassis mounting inside rack gear (rail screws are M6 or 10-32)

4-6mm · reported · source

holds the handle nut retainer plate on baitcasters

3-10mm · confirmed · source

locks the timing pulley onto the motor shaft

3-4mm · reported · source

secures the plate to a camera baseplate

4-6mm · reported · source

Small reel handle and drag knob screws

4-8mm · reported

Internal lens and bezel retention

4-6mm · reported

Stainless screws joining handles and ratchets

4-10mm · reported

Faceplate and knob screws in restoration

4-8mm · reported

Official spares kit is predominantly M3 sizes

4-20mm · reported · source

M3 x 0.5 retaining screw reported for Meade 1.25in 2x Ultima Barlow

4-8mm · reported · source

0.50mm pitch, head 5.32-5.68mm, 2.5mm hex key

4-30mm · confirmed · source

Head 5.6mm diameter, 1.65mm high

4-30mm · confirmed · source

ISO 14581 covers M1.6-M10 Torx countersunk screws — the profile behind many laptop and device screws

4-20mm · reported · source

Countersunk M3 x 4mm screws for Dell and HP 2.5-inch drive trays

4mm · reported · source

Zebra scanner attaches to the mounting bracket with 2x M3 x 4mm Phillips flat-head screws

4mm · confirmed · source

M3 machine screws from M3x4 to M3x40 listed by part code in the official Prusa cheatsheet

4-40mm · confirmed · source

disctech product page sells 'Counter-Sunk Screws (M3 x 4mm) for SFF 2.5 Dell & HP trays', explicitly stating M3 thread for drive tray mounting.

4mm · confirmed · source

GPU large-head screw securing GPU in riser cable bracket

4 · confirmed · source

Internal full rewinder module and lower front panel fastened with screws called out as M3*8L (torque 10.5/7.5 kgf.cm) and separate M4*8L screw for rewinder media guard limiter

4 mm, 6 mm, 8 mm · confirmed · source

M3*L4mm mechanical screws for the anti-theft lock

4mm · confirmed · source

Cover, frame and mechanism screws listed as M3x4, M3x6, M3x8

4-8mm · confirmed · source

Four front mounting holes, M3 x 0.5 tapped 4.5mm deep minimum

4-8mm · confirmed · source

Front mounting holes tapped M3, 3.18mm deep

4-6mm · confirmed · source

M3 x 4 hex socket set screws clamping pulley to motor shaft

3-6mm · confirmed · source

Official Aimpoint spare part 11866, M3x4 screws

4mm · confirmed · source

M3x4 mount screws for Micro series sights

4mm · confirmed · source

Four flat head case-to-cover screws

4mm · confirmed · source

M3 x 0.5 self-clinching standoff for sheet metal chassis

4mm · confirmed · source

Three new M3 x 4mm countersunk screws fix the silicone gobo rotation gear; M3 x 8 Torx pan head elsewhere

4mm / 8mm · confirmed · source

M3 x 3mm and M3 x 10mm socket dome screws for heater block / nozzle assembly

3-10mm · confirmed · source

M3 x 4mm and M3 x 8mm hex cap screws in the frame hardware bag

4-8mm · confirmed · source

Washer-head Phillips M3 x 4, 6, 8 and 10mm chassis screws

4-10mm · confirmed · source

Self-tapping Phillips M3 x 4, 6 and 8mm screws

4-8mm · confirmed · source

Trus-head Phillips M3 x 4, 8, 10 and 25mm screws, some with star washer

4-25mm · confirmed · source

Anodized accessory thumb screws explicitly sold in M3 and M4, with M3 commonly used for smaller eyepiece/accessory threads

M3x12, M4x12 · confirmed · source

Service manual specifies M3 fasteners in multiple lengths (M3x4, M3x5, M3x7.5, M3x10, M3x20, M3x25) for internal assembly, sensor brackets and covers

M3x4, M3x5, M3x7.5, M3x10, M3x20, M3x25 · confirmed · source

Parts code AWU 3X4SA = M3x4mm frame screw; AB3X10SA = M3x10mm; AHU3X8SA = M3x8mm

4mm, 8mm, 10mm · likely · source

metal shield to panel (2)

4mm · confirmed · Source: Dell P2425DE Teardown Instructions Rev A00

display middle-frame to panel (17)

4mm · confirmed · Source: Dell P2725DE Teardown Instruction Rev A00

middle frame to panel (11 + 5)

5mm and 4mm · confirmed · Source: Dell U2725QE Teardown Instruction

chassis / panel screws 1-15

4mm · confirmed · Source: Dell S2425H Simplified Service Manual

small bracket retention screws (2)

4mm · confirmed · Source: HP E24d/E27d G4 Maintenance and Service Guide

four case mounting screws for grounding and mechanical integrity

4mm max penetration · confirmed · Source: NovAtel OEM7 Installation and Operation User Manual OM-20000168 v18

SMT PCB standoff for mounting boards to housings or other boards

0.5-16mm standoff height · confirmed · Source: we-online.com WA-SMSI product page

metal frame to panel screws (2x)

4mm · confirmed · source

Non-standard solar panel clip fixed with an M3 x 4 mm pan-head stainless screw and lock washer; base plate to chassis walls and cover plate each use six M3 x 5 screws

4 mm and 5 mm · confirmed · source

Parts listing: 'Diebold Nixdorf ESC Cross Screw M3*4*6 ATM Parts 49221808000F' — screw described explicitly as M3

M3x4x6 mm (head dia x length variant) · confirmed — Diebold Nixdorf OEM parts listing · source