Juki MF-7900 industrial coverstitch machine screw size
M3 / M4 / M5 / M6 · 4 to 16 mm long
If you are replacing a screw on Juki MF-7900 industrial coverstitch machine, the thread is M3, M4, M5 and M6 in lengths from 4 to 16 mm.
There are 5 separate fitment records for it, including flat machine screw SM-6030800-SP, pitch 0.5 (M3), screw SM-6041202-TP, pitch 0.7 (M4) and set screw SM-8040412-TP (M4), plus 2 more in the table below.
Head and drive, as the sources state them: set screw (headless) head and Hex socket (Allen) drive.
5 of the 5 records are marked confirmed, drawn from 1 source (juki.co.jp).
For reference, M3 is 3 mm across the threads at 0.5 mm pitch. The imperial size people confuse it with: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3.
Juki MF-7900 industrial coverstitch machine 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 | flat machine screw SM-6030800-SP, pitch 0.5 | Confirmed |
| M4 | 12 mm | 0.7 mm | not stated | not stated | screw SM-6041202-TP, pitch 0.7 | Confirmed |
| M4 | 4 mm | 0.7 mm | Set screw (headless) | not stated | set screw SM-8040412-TP | Confirmed |
| M5 | 16 mm | 0.8 mm | not stated | Hex socket (Allen) | hex socket bolt SM-6051602-TP, pitch 0.8 | Confirmed |
| M6 | 12 mm | 1 mm | Set screw (headless) | not stated | set screw SM-8061212-TP | Confirmed |
Fitment records and sources
flat machine screw SM-6030800-SP, pitch 0.5
pitch 0.5 mm · tap 2.5 mm · clearance 3.4 mm · PH1 / Torx T10
screw SM-6041202-TP, pitch 0.7
pitch 0.7 mm · tap 3.3 mm · clearance 4.5 mm · PH2 / Torx T20
set screw SM-8040412-TP
pitch 0.7 mm · tap 3.3 mm · clearance 4.5 mm · PH2 / Torx T20
hex socket bolt SM-6051602-TP, pitch 0.8
pitch 0.8 mm · tap 4.2 mm · clearance 5.5 mm · PH2 / Torx T25
set screw SM-8061212-TP
pitch 1 mm · tap 5 mm · clearance 6.6 mm · PH3 / Torx T30
How to check the screw before you buy
- Industrial parts lists usually give the full callout (thread, length, head, grade); match all four, not just the thread.
- Diameter: across the threads an M3 screw measures about 3 mm with calipers (usually a hair under). This device also uses M4 / M5 / M6, so measure each screw rather than assuming they match.
- 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 4–16 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 / M4 / M5 / M6
- Some sewing-machine screws are labeled with metric-looking but slightly nonstandard sizes (e.g. M3.3) that are not true ISO M3 and are not interchangeable with standard M3 hardware.
- Water heater elements use pipe threads (NPSM/NPT), not metric machine screws.
- Some scooters and appliances use self-tapping screws of similar diameter rather than true M5 machine threads.
- UR cobot flange bolts are commonly sold/quoted as 'M6 bolts' but the required length depends on the tool thickness; UR's own guidance is bolt class M6-8.8 to ISO4762 without a fixed length, so length must be selected per adapter/tool stack-up, not assumed as a fixed mm value.
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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M6 x 12mm Black Wafer Head Brake Line Screws for GOTRAX G3, G4, GMAX & GMAX Ultra – 8-Pack Replacement
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The same screw also fits
Devices whose records share a thread with Juki MF-7900 industrial coverstitch machine, closest length match first.
- Eurodib LB Series Spiral Mixer (bakery dough mixer) electrical control box also M4 × 12 mm
- Makita GB801 also M5 × 16 mm
- Power tool battery pack shell also M4 × 12 mm
- DeWalt DW713 miter saw also M5 × 16 mm
- COSEL power supply terminal block (used in industrial/pump/water-treatment control panels) also M3 × 8 mm
- Power tool trigger switch also M3 × 8 mm
- INOX stainless hexagon head hygienic bolt with seal, for sanitary/food machinery also M6 × 12 mm
- Pinball cabinet hardware (EU restorations) also M4 × 12 mm
Questions about Juki MF-7900 industrial coverstitch machine screws
- What size screw does Juki MF-7900 industrial coverstitch machine use?
- M3 × 8 mm for flat machine screw SM-6030800-SP, pitch 0.5; M4 × 12 mm for screw SM-6041202-TP, pitch 0.7; M4 × 4 mm for set screw SM-8040412-TP; M5 × 16 mm for hex socket bolt SM-6051602-TP, pitch 0.8; M6 × 12 mm for set screw SM-8061212-TP.
- How long are the screws in Juki MF-7900 industrial coverstitch machine?
- The records range from 4 to 16 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 Juki MF-7900 industrial coverstitch machine?
- 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 Juki MF-7900 industrial coverstitch machine?
- TechSpareWarehouse (our own store) lists M3 x 8mm, which matches the length in the records above.