🔧 High Tensile Grade 12.9 Cup Point Grub Screws – Allen Socket Set Screws M2 to M10 | DIN916
🏷️ Brand: HomeDIYer Fastener | DIN916 | Grade 12.9 Alloy Steel | Black Uncoated | Hex Keys Included
📌 Overview — Extreme strength for locking shafts, gears, and collars. When you need to secure a component onto a shaft or prevent rotation, standard fasteners won't cut it. Our Grade 12.9 Cup Point Grub Screws (also known as socket set screws) are made from high-tensile alloy steel with a tensile strength of 1220 MPa – one of the strongest metric set screws available. The cup point bites into the mating surface for a positive lock, while the hex socket drive allows precise torque application. These black uncoated screws are perfect for industrial machinery, motor shafts, pulleys, tooling, and any application where vibration or torque could loosen ordinary screws. Fully threaded from M2 to M10, and we include the correct hex keys with your order. Choose your length – built for professionals who demand reliability.
✨ Key Features of Grade 12.9 Cup Point Set Screws
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Grade 12.9 High Tensile Steel – Ultimate tensile strength of 1220 MPa (177,000 psi), yield strength 1100 MPa – far stronger than stainless or Grade 8.8.
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Cup Point Design – The concave cup point bites into the shaft or surface, providing excellent holding power and resistance to loosening.
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Hex Socket Drive (Allen Key) – Allows high torque application without cam-out; hex keys included with your order (0.9mm to 5mm).
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DIN916 Standard – Precision metric threads and dimensions for reliable fit in standard threaded holes.
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Fully Threaded (Overall Length) – Length is measured overall (includes the head – grub screws have no protruding head).
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Wide Metric Range M2 to M10 – From miniature electronics (M2) to heavy machinery (M10). Order any length you need.
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Self-Color Uncoated (Black) – Natural steel finish with light oil for corrosion resistance during storage. Not for prolonged outdoor use without additional coating.
📏 Technical Specifications – Cup Point Grub Screws (DIN916, Metric Coarse)
| Thread Size |
Thread Pitch (mm) |
Allen Key Size (mm) |
| M2 |
0.4 |
0.9 |
| M3 |
0.5 |
1.5 |
| M4 |
0.7 |
2.0 |
| M5 |
0.8 |
2.5 |
| M6 |
1.0 |
3.0 |
| M8 |
1.25 |
4.0 |
| M10 |
1.5 |
5.0 |
💡 Length & ordering info: Grub screws have no head – length is measured overall (total screw length). Choose your preferred length (e.g., 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, 25mm, 30mm) — sold as per your requirement. Hex keys (Allen wrenches) are included with your order – one key per size or a multi-tool, depending on pack.
⚠️ Material note: Grade 12.9 steel is extremely strong but is not stainless steel. These screws have a black self-color finish with light oil to prevent rust during storage. For outdoor or wet environments, apply a protective coating (e.g., oil, paint, or use stainless set screws). Ideal for dry, indoor, or oil-lubricated applications like machinery, engines, and tooling.
❓ Frequently Asked Questions – Grade 12.9 Cup Point Grub Screws
What is the difference between Grade 12.9 and Grade 8.8 or stainless steel?
📊 Grade 12.9 is the highest common metric strength class for steel fasteners (1220 MPa tensile). Grade 8.8 is about 800 MPa, and A2-70 stainless is 700 MPa. For locking shafts, pulleys, or any high-stress application, 12.9 provides maximum holding power and shear resistance.
Do these screws come with hex keys? What sizes?
✅ Yes, the box includes the correct hex (Allen) keys for the screws you order. For example, M2 screws come with a 0.9mm key, M3 with 1.5mm, up to M10 with 5mm. No need to buy separate tools.
Will these rust? Are they suitable for outdoor use?
🌧️ Grade 12.9 steel is not corrosion-resistant like stainless. The black uncoated finish will rust if exposed to moisture over time. For outdoor or marine applications, we recommend A2 or A4 stainless steel grub screws (sold separately). These 12.9 screws are ideal for indoor machinery, engines, tools, and dry environments.
What is the cup point used for? How does it lock?
🔩 The cup point has a concave, cup-shaped tip that digs into the shaft or surface when tightened. This creates a positive mechanical lock that resists loosening from vibration or torque. Cup points are the most common type for set screws, ideal for shafts, collars, and gears.
What lengths are available? Can I get custom lengths?
📦 “As per Your Choice” – select the exact length you need. Common lengths: 3mm to 30mm (3,4,5,6,8,10,12,16,20,25,30mm). Custom lengths available for bulk orders. Contact us with your requirements.
⚙️ HomeDIYer Fastener — High-strength precision fasteners for demanding applications. Order your exact size, length, and quantity today.
