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.

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.

Omron E3T ultracompact photoelectric sensor (used for conveyor/AGV object detection) screw size

M3 · 6 to 15 mm long

If you are replacing a screw on Omron E3T ultracompact photoelectric sensor (used for conveyor/AGV object detection), the thread is M3 in lengths from 6 to 15 mm.

Where it is used: datasheet explicitly lists 'M3-mounting Sensors' with accessory 'Bolt with hexagonal hole (M3×6)' and a second mounting bracket bolt 'M3×15'; tightening torque spec given as 'M3-mounting Sensors: 0.5 N·m max'.

This entry is marked confirmed and comes from edata.omron.com.au.

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.

Omron E3T ultracompact photoelectric sensor (used for conveyor/AGV object detection) screw specifications

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

Thread	Length	Pitch	Head	Drive	Torque	Where it goes	Status
M3	6–15 mm	0.5 mm	not stated	not stated	0.5 N·m	Datasheet explicitly lists 'M3-mounting Sensors' with accessory 'Bolt with hexagonal hole (M3×6)' and a second mounting bracket bolt 'M3×15'; tightening torque spec given as 'M3-mounting Sensors: 0.5 N·m max'	Confirmed

Fitment records and sources

M36-15mmconfirmed

Datasheet explicitly lists 'M3-mounting Sensors' with accessory 'Bolt with hexagonal hole (M3×6)' and a second mounting bracket bolt 'M3×15'; tightening torque spec given as 'M3-mounting Sensors: 0.5 N·m max'

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 6–15 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.

Common mix-ups with M3

Many gas-detector and sensor manuals only give a torque spec (e.g. '0.5 N·m max') without repeating the thread size at every mention — the explicit M3 callout is usually only in the accessories/spare-parts table, not the main installation steps.
Terminal-block clamp screws have manufacturer-specific torque values — over-tightening cracks the block or crushes the wire.

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
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M3 x 8mm Phillips Wafer Head Screw for SLA Resin 3D Printer VAT Film - Single Replacement Black $0.10 each · min. 50
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M3 x 6mm Phillips Wafer Head Screw for Boutique Guitar Pedal Enclosure - Single Replacement Black $0.10 each · min. 50

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The same screw also fits

Devices whose records share a thread with Omron E3T ultracompact photoelectric sensor (used for conveyor/AGV object detection), closest length match first.

PEM self-clinching flush-head stud, sheet-metal enclosures (ATM/kiosk/POS chassis use case) also M3 × 6 mm
Eurorack modular synthesizer cases also M3 × 6–10 mm
Metcase Technomet-Control instrument enclosure also M3 × 6–8 mm
Samsung WA50M7450AW top-load washer service manual - control board/wire harness connector screws also M3 × 8 mm
J-GUANG 301R / 2EDGK-5.0 & 5.08 PCB screw terminal block also M3 × 6 mm
Canford D-series BNC panel connector (broadcast/RF) also M3 × 6–10 mm
2.5in SATA / SAS hard drives and SSDs (SFF-8201) also M3 × 6–7 mm
Eurorack module panel mounting also M3 × 6–10 mm

Questions about Omron E3T ultracompact photoelectric sensor (used for conveyor/AGV object detection) screws

What size screw does Omron E3T ultracompact photoelectric sensor (used for conveyor/AGV object detection) use?: M3 × 6–15 mm for datasheet explicitly lists 'M3-mounting Sensors' with accessory 'Bolt with hexagonal hole (M3×6)' and a second mounting bracket bolt 'M3×15'; tightening torque spec given as 'M3-mounting Sensors: 0.5 N·m max'.
How long are the screws in Omron E3T ultracompact photoelectric sensor (used for conveyor/AGV object detection)?: The records range from 6 to 15 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 Omron E3T ultracompact photoelectric sensor (used for conveyor/AGV object detection)?: 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.
How tight should the M3 screw on Omron E3T ultracompact photoelectric sensor (used for conveyor/AGV object detection) be?: The source gives 0.5 N·m for datasheet explicitly lists 'M3-mounting Sensors' with accessory 'Bolt with hexagonal hole (M3×6)' and a second mounting bracket bolt 'M3×15'; tightening torque spec given as 'M3-mounting Sensors: 0.5 N·m max'.
Where can I buy replacement screws for Omron E3T ultracompact photoelectric sensor (used for conveyor/AGV object detection)?: TechSpareWarehouse (our own store) lists M3 x 6mm, M3 x 8mm and M3 x 10mm, which match lengths in the records above.

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