What size screw does RatRig V-Core 3.1 X-axis assembly use?

M3 × 8 mm for 2020 extrusion to X-carriage fasteners.

How long are the screws in RatRig V-Core 3.1 X-axis assembly?

The record gives 8 mm. Measure the original from under the head (overall for a countersunk head) to confirm before ordering.

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 RatRig V-Core 3.1 X-axis assembly?

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 RatRig V-Core 3.1 X-axis assembly?

TechSpareWarehouse (our own store) lists M3 x 8mm, which matches the length in the records above.

RatRig V-Core 3.1 X-axis assembly screw size

M3 · 8 mm long

RatRig V-Core 3.1 X-axis assembly takes M3 metric screws, 8 mm long.

Where it is used: 2020 extrusion to X-carriage fasteners.

This entry is marked confirmed and comes from wiki.ratrig.com.

An M3 screw is 3 mm in diameter with a 0.5 mm pitch, tapped with a 2.5 mm drill; imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3.

RatRig V-Core 3.1 X-axis assembly 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 mm	0.5 mm	not stated	not stated	2020 extrusion to X-carriage fasteners	Confirmed

Fitment records and sources

M38 mmconfirmed

2020 extrusion to X-carriage fasteners

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

Source

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 record states 8 mm. Going longer risks bottoming out or touching parts behind the hole; going shorter loses thread engagement.
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

2020 extrusion T-nuts come in M3/M4/M5 and are not interchangeable — M3 is accessory-only, M5 is structural.
Pond/aquarium equipment manuals aimed at consumers rarely specify exact thread pitch or length for internal fasteners, since these are considered non-user-serviceable; distributor-level assembly/service manuals (e.g., Maytronics internal documents) are a better source than end-user guides.

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.

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The same screw also fits

Devices whose records share a thread with RatRig V-Core 3.1 X-axis assembly, closest length match first.

Voron 2.4 electronics bay also M3 × 8 mm
NEMA 17 stepper motor mounting also M3 × 8 mm
Ender 3 V2 hotend and hotend cover also M3 × 8 mm
Arduino Mega 2560 mounting holes also M3 × 8 mm
ESP32 DevKit boards also M3 × 8 mm
Arduino Uno / Mega mounting holes also M3 × 8 mm
Arduino Uno / shield mounting holes also M3 × 8 mm
Voron 2.4 3D printer also M3 × 8 mm

Questions about RatRig V-Core 3.1 X-axis assembly screws

What size screw does RatRig V-Core 3.1 X-axis assembly use?: M3 × 8 mm for 2020 extrusion to X-carriage fasteners.
How long are the screws in RatRig V-Core 3.1 X-axis assembly?: The record gives 8 mm. Measure the original from under the head (overall for a countersunk head) to confirm before ordering.
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 RatRig V-Core 3.1 X-axis assembly?: 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 RatRig V-Core 3.1 X-axis assembly?: TechSpareWarehouse (our own store) lists M3 x 8mm, which matches the length in the records above.

Heads up: shipping delay