How long are the screws in GT2 timing pulley grub screws?

The records range from 3 to 6 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 GT2 timing pulley grub screws?

The source lists a Hex socket (Allen) drive. Standard M3 heads otherwise take PH1 (Phillips) or T10 (Torx), or 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 GT2 timing pulley grub screws?

TechSpareWarehouse (our own store) lists M3 x 3mm, M3 x 4mm and M3 x 5mm, which match lengths in the records above.

GT2 timing pulley grub screws screw size

M3 · 3 to 6 mm long

The screws used on GT2 timing pulley grub screws are M3 in lengths from 3 to 6 mm.

It is listed for M3 x 4 hex socket set screws clamping pulley to motor shaft.

Head and drive, as the source states them: set screw (headless) head and Hex socket (Allen) drive.

This entry is marked confirmed and comes from robotdigg.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.

GT2 timing pulley grub screws 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	3–6 mm	0.5 mm	Set screw (headless)	Hex socket (Allen)	M3 x 4 hex socket set screws clamping pulley to motor shaft	Confirmed

Fitment records and sources

M33-6mmconfirmed

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

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

Source

How to check the screw before you buy

Printer and CNC builds usually publish a bill of materials; when it lists a length, follow it, since extrusion T-nuts and motor faces have fixed thread depths.
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: for set screw (headless) screws, measure from under the head to the tip (countersunk heads are the exception: they are measured overall).
The records span 3–6 mm, which means different positions take different lengths — match each hole to its own screw.
Driver: the source names a Hex socket (Allen) drive. For comparison, standard M3 heads take PH1 (Phillips) or T10 (Torx), or a 2.5 mm hex key.
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

On FPV motors, screw length is safety-critical: one turn too long and the screw crushes the motor windings. Measure arm + base depth, and dry-fit before powering up.
M3 is the most common FPV screw, but length must match arm and stack thickness — too long can short motor windings or crack frame plates.

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 GT2 timing pulley grub screws, closest length match first.

Bondtech 17-tooth steel gear also M3 × 3 mm
Voron 2.4 / Trident also M3 × 6 mm
Voron 2.4 gantry and carriage hardware also M3 × 6 mm
Bambu Lab X1 / P1 / A1 frame and toolhead also M3 × 6 mm
Bambu Lab X1/P1/AMS spare screw kit also M3 × 4–6 mm
Robotiq low-profile gripper coupling also M3 × 5 mm
CNC / V-slot limit switches & sensors also M3 × 6 mm
NEMA 17 stepper motor faceplate also M3 × 4–6 mm

Questions about GT2 timing pulley grub screws screws

What size screw does GT2 timing pulley grub screws use?: M3 × 3–6 mm for M3 x 4 hex socket set screws clamping pulley to motor shaft.
How long are the screws in GT2 timing pulley grub screws?: The records range from 3 to 6 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 GT2 timing pulley grub screws?: The source lists a Hex socket (Allen) drive. Standard M3 heads otherwise take PH1 (Phillips) or T10 (Torx), or 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 GT2 timing pulley grub screws?: TechSpareWarehouse (our own store) lists M3 x 3mm, M3 x 4mm and M3 x 5mm, which match lengths in the records above.

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