How long are the screws in Keystone metric hex PCB standoff?

The records range from 6 to 25 mm depending on the position, so match each screw to its own hole.

What is the thread pitch of an M3 screw?

0.5 mm (coarse), which is the standard pitch for M3 machine screws; a 0.35 mm fine pitch exists but is uncommon. The tap drill is 2.5 mm and the normal clearance hole is 3.4 mm.

What screwdriver do I need for Keystone metric hex PCB standoff?

The sources do not name the drive. For M3, Phillips heads normally take PH1 and Torx heads T10; socket heads take a 2.5 mm hex key.

Can I use an imperial screw instead of M3?

No. Imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3. Use a true M3 screw so it does not cross-thread or strip the hole.

Where can I buy replacement screws for Keystone metric hex PCB standoff?

TechSpareWarehouse (our own store) lists M3 x 6mm, M3 x 8mm and M3 x 10mm, which match lengths in the records above.

Keystone metric hex PCB standoff screw size

M3 · 6 to 25 mm long

If you are replacing a screw on Keystone metric hex PCB standoff, the thread is M3 in lengths from 6 to 25 mm.

Where it is used: catalog lists hex standoffs with M3 thread, lengths 6.0-25.0mm.

This entry is marked confirmed and comes from yic-electronics.com.

For reference, M3 is 3 mm across the threads at 0.5 mm pitch. The imperial size people confuse it with: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3.

Keystone metric hex PCB standoff screw specifications

One row per fitment record. Head, drive are shown only where the source states them; pitch is the ISO coarse pitch for the thread.

Thread	Length	Pitch	Head	Drive	Where it goes	Status
M3	6–25 mm	0.5 mm	not stated	not stated	Catalog lists hex standoffs with M3 thread, lengths 6.0-25.0mm	Confirmed

Fitment records and sources

M36-25mmconfirmed

Catalog lists hex standoffs with M3 thread, lengths 6.0-25.0mm

pitch 0.5 mm · tap 2.5 mm · clearance 3.4 mm · PH1 / Torx T10

Source

How to check the screw before you buy

Board standoffs and enclosure bosses set the usable length: the screw should clamp the board without bottoming in the standoff.
Diameter: across the threads an M3 screw measures about 3 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
Pitch: 0.5 mm from one thread crest to the next (20 crests per centimetre). A thread pitch gauge or the pitch-gauge tool settles it in seconds.
Length: measure from under the head to the tip for pan, button, wafer and cap heads; countersunk (flat) heads are measured overall.
The records span 6–25 mm, which means different positions take different lengths — match each hole to its own screw.
Driver: the source does not name the drive. Standard M3 heads take PH1 for Phillips and T10 for Torx, and a 2.5 mm hex key for socket heads; a bit that fits loosely will cam out and strip the head.
Tightening: no device-specific torque is published in these records. The site's general figure for M3 is about 80-130 N·cm into metal threads and 35-60 N·cm into plastic bosses; snug it up and stop.

Common mix-ups with M3

Intel's ATX and microATX specs never state a metric standoff thread; PC motherboard standoffs are usually imperial 6-32, and PC fan screws are commonly 6-32 self-tapping.
Model rocketry altimeter manuals (Apogee AIM USB, Rocketronics AltiMAX G4, RockeTiltometer) contain no explicit metric screw thread callouts in their documentation; mounting is typically via hook-and-loop or generic standoffs, so no metric fitment can be confirmed for this category.

Pitch gauge · Screw size finder · Torque guide

Buy these screws at TechSpare Warehouse

In stock and shipped from South Carolina. Our black screws are Phillips wafer head (low profile); match the head style and length to the original before you order.

M3 x 6mm Replacement Screws for XLR Audio Connectors Phillips Wafer Head 50-Pack $4.99
M3 x 6mm Phillips Wafer Head Carbon Steel Machine Screws for XLR Audio Connectors | 50-Pack (Black) $4.99
M3 x 8mm Screws for Leather Spike Attachments Guitar Straps 10-Pack $4.99
M3 x 8mm Phillips Wafer Head Screw for SLA Resin 3D Printer VAT Film - Single Replacement Black $0.10 each · min. 50
M3 x 10mm Phillips Wafer Head Screw for Sim Racing Wheel Paddle Shifter - Single Replacement Black $0.10 each · min. 50
M3 x 10mm Phillips Wafer Head Screw for RC Car/Truck Chassis Mount - Single Replacement Black $0.10 each · min. 50
M3 x 10mm Phillips Wafer Head Screw for 3D Printer Frame Assembly - Single Replacement Black $0.10 each · min. 50
M3 x 6mm Phillips Wafer Head Screw for 3D Printer Frame Assembly - Single Replacement Black $0.10 each · min. 50

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The same screw also fits

Devices whose records share a thread with Keystone metric hex PCB standoff, closest length match first.

HARTING connector insert fixing screw also M3 × 10 mm
Apple AirPort Extreme internals also M3 × 6–10 mm
Ubiquiti UniFi AP ceiling mount also M3 × 20–25 mm
Guitar pedal enclosure also M3 × 6–10 mm
Eurorack synth rails (standard panel mounting) also M3 × 6–10 mm
Eurorack module/rail mounting screw also M3 × 6 mm
AutomationDirect DPM-BKT1 panel meter bracket also M3 × 6 mm
Network switch & patch panel internals also M3 × 6 mm

Questions about Keystone metric hex PCB standoff screws

What size screw does Keystone metric hex PCB standoff use?: M3 × 6–25 mm for catalog lists hex standoffs with M3 thread, lengths 6.0-25.0mm.
How long are the screws in Keystone metric hex PCB standoff?: The records range from 6 to 25 mm depending on the position, so match each screw to its own hole.
What is the thread pitch of an M3 screw?: 0.5 mm (coarse), which is the standard pitch for M3 machine screws; a 0.35 mm fine pitch exists but is uncommon. The tap drill is 2.5 mm and the normal clearance hole is 3.4 mm.
What screwdriver do I need for Keystone metric hex PCB standoff?: The sources do not name the drive. For M3, Phillips heads normally take PH1 and Torx heads T10; socket heads take a 2.5 mm hex key.
Can I use an imperial screw instead of M3?: No. Imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3. Use a true M3 screw so it does not cross-thread or strip the hole.
Where can I buy replacement screws for Keystone metric hex PCB standoff?: TechSpareWarehouse (our own store) lists M3 x 6mm, M3 x 8mm and M3 x 10mm, which match lengths in the records above.

Heads up: shipping delay