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When standard hardware isn’t strong enough, Grade 10.9 flanged button head screws deliver the clamping force your application demands. With a tensile strength of 1040 MPa (151,000 psi) — significantly stronger than Grade 8.8 or A2 stainless — these ISO7380-2 fasteners are built for heavy machinery, automotive components, industrial equipment, and structural assemblies where failure is not an option.
Each screw features an integrated wide flange that eliminates the need for a separate washer, distributing load evenly and protecting your work surface. The low-profile button head and hex socket (Allen) drive allow high torque application in tight spaces without cam-out. Available fully threaded in M3, M4, M5, M6, and M8, with lengths from 6mm to 40mm. Hex bits are included with every order.
These black self-color (uncoated) alloy steel screws are the go-to choice for engine bay fastening, CNC machine frames, RC vehicle chassis, and any application where a clean, snag-free head profile and serious holding power are both required.
Grade 10.9 strength handles the vibration and thermal cycling of engine components, brackets, and chassis mounts where standard hardware would loosen or fail.
The high clamping force and integrated flange make these screws ideal for securing linear rails, motor mounts, and structural panels on CNC routers and industrial equipment.
The low-profile button head and compact flange keep assemblies snag-free and aerodynamic, while Grade 10.9 strength handles the shock loads of off-road RC and drone frames.
Wherever a clean, professional fastener with serious holding power is needed — workbench frames, jig fixtures, steel fabrication — these screws deliver without requiring a separate washer.
| Standard | ISO7380-2 (Flanged Button Head Socket Cap Screw) |
|---|---|
| Material | Grade 10.9 Alloy Steel |
| Tensile Strength | 1040 MPa (151,000 psi) minimum |
| Yield Strength | 900 MPa minimum |
| Drive Type | Hex Socket (Allen / Internal Hex) |
| Head Style | Flanged Button Head (low-profile dome with integrated washer flange) |
| Thread Standard | ISO Metric Coarse |
| Thread Diameters | M3, M4, M5, M6, M8 |
| Available Lengths | 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, 25mm, 30mm, 40mm (see variant options) |
| Thread Type | Fully threaded (length measured from underside of head) |
| Finish | Black self-color (uncoated, light oil for storage) |
| Hex Key Sizes Included | M3 → 2mm | M4 → 2.5mm | M5 → 3mm | M6 → 4mm | M8 → 5mm |
| Corrosion Resistance | Not corrosion-resistant — for dry, indoor, or oil-lubricated environments |
| Thread Size | Thread Pitch (mm) | Head Diameter (mm) | Head Height (mm) | Allen Key Size (mm) |
|---|---|---|---|---|
| M3 | 0.50 | 6.9 | 1.65 | 2.0 |
| M4 | 0.70 | 9.4 | 2.2 | 2.5 |
| M5 | 0.80 | 11.8 | 2.8 | 3.0 |
| M6 | 1.00 | 13.6 | 3.3 | 4.0 |
| M8 | 1.25 | 17.6 | 4.4 | 5.0 |
Grade 10.9 has a minimum tensile strength of 1040 MPa (151,000 psi) and a yield strength of 900 MPa. For comparison: Grade 8.8 is typically 800 MPa tensile, and A2-70 stainless is 700 MPa. Grade 10.9 is the standard choice for high-stress bolted joints in automotive, machinery, and structural applications where Grade 8.8 is insufficient.
No. The integrated wide flange acts as a built-in washer, distributing clamping load over a wider bearing area and protecting the work surface. This eliminates the need for a separate flat washer in most applications, saves assembly time, and prevents washer loss.
Yes, all sizes are fully threaded for maximum grip strength. Length is measured from the underside of the head (not including head height). For example, an M5 × 16mm screw has 16mm of threaded shank below the head flange.
Yes, the correct hex (Allen) bits are included with every order: M3 → 2mm, M4 → 2.5mm, M5 → 3mm, M6 → 4mm, M8 → 5mm. You’ll have everything needed to install them immediately without sourcing additional tools.
Grade 10.9 alloy steel is not stainless and will rust if exposed to moisture or outdoor conditions. The black uncoated finish includes light oil for storage protection only. For outdoor or wet environments, apply a rust-preventative coating (paint, zinc spray) or switch to A2/A4 stainless steel flanged button head screws. These are best suited for dry, indoor, or oil-lubricated applications such as engines, machinery, and tooling.
ISO7380-1 is a standard button head socket cap screw without a flange. ISO7380-2 adds an integrated wide flange under the head, which acts as a built-in washer. These screws follow ISO7380-2, meaning they include the flange for improved load distribution and surface protection.
These screws use standard ISO metric coarse thread pitches: M3 × 0.50mm, M4 × 0.70mm, M5 × 0.80mm, M6 × 1.00mm, M8 × 1.25mm. They are compatible with standard metric nuts, tapped holes, and threaded inserts using the same coarse pitch. They are not compatible with metric fine thread or UNC/UNF inch threads.
Yes, Grade 10.9 flanged button head screws are commonly used with aluminum extrusions, aluminum plate, and engineering plastics. The integrated flange helps prevent pull-through in softer materials. Always pre-drill a clearance hole or use appropriate threaded inserts. Be aware that Grade 10.9 steel and aluminum can experience galvanic corrosion in wet environments — apply a barrier coating or use stainless hardware for outdoor aluminum assemblies.
