PC radiator fan screws (Koolance/HWLabs/Swiftech) screw size
M4 · 20 to 30 mm long
If you are replacing a screw on PC radiator fan screws (Koolance/HWLabs/Swiftech), the thread is M4 in lengths from 20 to 30 mm.
The record covers thicker radiators from some brands use M4 instead of M3.
This entry is marked confirmed and comes from mnpctech.com.
For reference, M4 is 4 mm across the threads at 0.7 mm pitch. The imperial size people confuse it with: #8-32 (4.17 mm) — the standard US PC/rack screw, close but not the same.
PC radiator fan screws (Koolance/HWLabs/Swiftech) 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 |
|---|---|---|---|---|---|---|
| M4 | 20–30 mm | 0.7 mm | not stated | not stated | Thicker radiators from some brands use M4 instead of M3 | Confirmed |
Fitment records and sources
Thicker radiators from some brands use M4 instead of M3
pitch 0.7 mm · tap 3.3 mm · clearance 4.5 mm · PH2 / Torx T20
How to check the screw before you buy
- Laptop covers and brackets often mix two or three lengths of the same thread, so lay the screws out in the order they came out (a magnetic mat or a sheet of paper with the hole pattern drawn on it works).
- Diameter: across the threads an M4 screw measures about 4 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
- Pitch: 0.7 mm from one thread crest to the next (14.29 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 20–30 mm, which means different positions take different lengths — match each hole to its own screw.
- Driver: the source does not name the drive. Standard M4 heads take PH2 for Phillips and T20 for Torx, and a 3 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 M4 is about 2.0-3.0 N·m into metal threads and 0.8-1.4 N·m into plastic bosses; snug it up and stop.
Common mix-ups with M4
- M4 and 6-32 UNC share a nominal diameter with different pitch — a classic cross-thread in US-market kits.
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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M4 x 20mm Black Wafer Head Pan Screw Screws for Honda Accord 1980-1989 & Civic 1978-1979 (93500-04020) – 10-Pack Replacement
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M4 x 20mm Black Wafer Head Phillips Machine Screws (8mm Thin Flat Head) for Monitor VESA Brackets & PC Cases
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M4 x 25mm Black Wafer Head TV Stand Screws for Vizio V4K50M-0807, VQD50R-1007, VQP75C-84 & TCL 40S303, 43S303 – 8-Pack Replacement
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M4 x 25mm Black Wafer Head Assembly Screws for xTool D1 Pro Laser Engraver – 10-Pack Replacement
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More in Laptops & PCs
The same screw also fits
Devices whose records share a thread with PC radiator fan screws (Koolance/HWLabs/Swiftech), closest length match first.
- Makita 6095D cordless driver drill also M4 × 22 mm
- LG 50PZ950U also M4 × 20 mm
- Phoenix Contact CHARX EV charging connector also M4 × 20 mm
- Flat-pack cam lock bolt also M4 × 25–30 mm
- LG 55LW9500 also M4 × 20 mm
- Zodiac Vortex 3 Saphir robotic pool cleaner also M4 × 25 mm
- Panasonic TC-L42E60 also M4 × 25 mm
- LG 60PZ950U also M4 × 20 mm
Questions about PC radiator fan screws (Koolance/HWLabs/Swiftech) screws
- What size screw does PC radiator fan screws (Koolance/HWLabs/Swiftech) use?
- M4 × 20–30 mm for thicker radiators from some brands use M4 instead of M3.
- How long are the screws in PC radiator fan screws (Koolance/HWLabs/Swiftech)?
- The records range from 20 to 30 mm depending on the position, so match each screw to its own hole.
- What is the thread pitch of an M4 screw?
- 0.7 mm (coarse), which is the standard pitch for M4 machine screws; a 0.5 mm fine pitch exists but is uncommon. The tap drill is 3.3 mm and the normal clearance hole is 4.5 mm.
- What screwdriver do I need for PC radiator fan screws (Koolance/HWLabs/Swiftech)?
- The sources do not name the drive. For M4, Phillips heads normally take PH2 and Torx heads T20; socket heads take a 3 mm hex key.
- Can I use an imperial screw instead of M4?
- No. Imperial look-alike: #8-32 (4.17 mm) — the standard US PC/rack screw, close but not the same. Use a true M4 screw so it does not cross-thread or strip the hole.