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When a standard pan head screw just doesn't spread the load enough — or when you need a fastener that looks clean and sits low — most builders and makers end up hunting for a truss head. Whether you're assembling electronics enclosures, securing sheet metal panels, building RC frames, or mounting thin acrylic or aluminum stock, the wrong head geometry causes pull-through, wobble, or an ugly finish. These black 304 stainless steel Phillips truss head machine screws are stocked specifically for those jobs.
Each pack contains fully threaded metric machine screws in your chosen size and quantity. Available in M3, M4, M5, and M6 diameters with lengths ranging from 4mm (≈5/32") to 50mm (≈1-31/32"). The truss head features a wide, low-profile dome with a flat underside for maximum bearing surface. Material is 304 stainless steel with a black finish for a clean, corrosion-resistant appearance. Pack quantities range from 5 to 50 pieces, depending on the size selected.
Typical applications include electronics chassis assembly, DIY enclosure fabrication, light sheet metal fastening, 3D printer frame construction, and hobby or RC vehicle builds where a low-profile black fastener is needed. These black metric machine screws are a go-to for makers who want function and a finished look in one fastener.
| Material | 304 Stainless Steel |
|---|---|
| Finish | Black (black oxide / black passivation) |
| Head Type | Truss Head (wide low-profile dome) |
| Drive Type | Phillips (PH1 for M3–M4; PH2 for M5–M6) |
| Thread Standard | ISO Metric (coarse pitch) |
| Available Diameters | M3, M4, M5, M6 |
| Available Lengths | 4mm (≈5/32") – 50mm (≈1-31/32") |
| Thread Type | Fully threaded machine screw |
| Pack Quantity Options | 5 / 10 / 20 / 50 pcs (varies by size) |
| Tensile Strength | See variant options |
| Country of Origin | Contact us to confirm |
Generally, the screw length should equal the thickness of the material being fastened plus enough thread engagement in the receiving part — typically 1.5× the screw diameter. For example, fastening a 3mm panel with an M4 screw into a tapped hole generally calls for a length of 8–12mm (≈5/16"–15/32"). Use the variant selector above to pick your size and length combination.
These screws are made from 304 stainless steel with a black finish. 304 stainless is an austenitic alloy that offers good corrosion resistance in most indoor and light outdoor environments. It is non-magnetic in its annealed state and widely used in electronics, food equipment, and general fabrication.
304 stainless steel generally performs well in light outdoor and humid environments. For harsh marine or highly corrosive conditions, 316 stainless steel is typically recommended. The black finish may show minor wear over time with prolonged outdoor exposure. For most sheltered outdoor applications, these will generally hold up well.
Yes. These are ISO metric coarse-pitch machine screws (M3, M4, M5, M6). They are compatible with standard metric nuts, threaded inserts, and tapped holes of the corresponding size. They are not compatible with UNC/UNF (inch) threads.
A truss head has a wider, lower-profile dome compared to a pan head, giving it a larger bearing surface that distributes clamping force over a greater area. This makes it well-suited for thin or soft materials where a smaller head might pull through. Unlike a flat head, it sits slightly above the surface rather than flush — so no countersinking is needed.
These screws use a Phillips drive. For M3 and M4 sizes, a PH1 bit is typically the correct fit. For M5 and M6, a PH2 bit is generally recommended. Always use a properly sized bit to avoid cam-out and head damage — especially important with smaller M3 screws.
Pack quantity depends on the size and length selected — options include 5, 10, 20, or 50 pieces per pack. The quantity is shown in the "Qty (pcs)" variant selector. If you need quantities beyond what's listed, please contact us to discuss bulk pricing.
Machine screws like these require a pre-tapped hole or a nut — they do not cut their own threads. If you're fastening into a pre-threaded metal insert, a nut, or a tapped hole, a machine screw is the correct choice. If you're driving directly into plastic, wood, or sheet metal without a pre-tapped hole, you would typically need a self-tapping or thread-forming screw instead.
