FDM hotend and extruder mounts (general) screw size
M3 · 8 to 20 mm long
Our records put FDM hotend and extruder mounts (general) on M3 screws in lengths from 8 to 20 mm.
Where it is used: creality/Prusa/Voron hotend and extruder bolts are M3.
This entry is marked reported and comes from docs.vorondesign.com.
M3 means a 3 mm nominal diameter with a 0.5 mm thread pitch. Imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3.
FDM hotend and extruder mounts (general) 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 | 8–20 mm | 0.5 mm | not stated | not stated | Creality/Prusa/Voron hotend and extruder bolts are M3 | Reported |
Fitment records and sources
Creality/Prusa/Voron hotend and extruder bolts are M3
pitch 0.5 mm · tap 2.5 mm · clearance 3.4 mm · PH1 / Torx T10
How to check the screw before you buy
- Into printed plastic, the screw either self-taps or needs a heat-set insert; machine screws straight into plastic strip easily.
- 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 8–20 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
- Telescope thumbscrews are sold in a wide non-metric legacy range too (1/4-20, 8-32, 10-32 on many Meade/Celestron mounts), so metric M3/M4 fitment applies mainly to newer/international accessory ecosystems (SkyWatcher, generic 1.25" accessories) and should not be assumed universal.
- M3 (3.0mm, 0.5mm pitch) is not #6-32 UNC (~3.5mm) — they look identical and cross-thread, the single most common PC-building mistake.
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 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
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M3 x 10mm Phillips Wafer Head Screw for RC Car/Truck Chassis Mount - Single Replacement Black
$0.10 each · min. 50
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M3 x 12mm Phillips Wafer Head Screw for Camera Cage & Battery Slide Mount - Pack of 50 Black
$6.49 -
M3 x 12mm Phillips Wafer Head Screw for Electric Scooter LCD Dashboard - Single Replacement Black
$0.10 each · min. 50
-
M3 x 12mm Phillips Wafer Head Screw for RC Car/Truck Chassis Mount - Single Replacement Black
$0.10 each · min. 50
-
M3 x 8mm Phillips Flat Head Countersunk Machine Screws Zinc Silver 100-Pack for RC & 3D Printers
$9.99
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Devices whose records share a thread with FDM hotend and extruder mounts (general), closest length match first.
- RatRig V-Core 3.1 (200x200) also M3 × 12 mm
- Ender 3 V3 KE cooling fan brackets also M3 × 8 mm
- Linear rail carriage block also M3 × 8 mm
- Voron 2.4 3D printer also M3 × 8–20 mm
- Arduino Uno / shield mounting holes also M3 × 8–10 mm
- Arduino Uno / Mega mounting holes also M3 × 8 mm
- ESP32 DevKit boards also M3 × 8 mm
- Arduino Mega 2560 mounting holes also M3 × 8–10 mm
Questions about FDM hotend and extruder mounts (general) screws
- What size screw does FDM hotend and extruder mounts (general) use?
- M3 × 8–20 mm for creality/Prusa/Voron hotend and extruder bolts are M3.
- How long are the screws in FDM hotend and extruder mounts (general)?
- The records range from 8 to 20 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 FDM hotend and extruder mounts (general)?
- 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 FDM hotend and extruder mounts (general)?
- TechSpareWarehouse (our own store) lists M3 x 8mm, M3 x 10mm and M3 x 12mm, which match lengths in the records above.