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Home / Screws / Grade 12.9 Headless Screw Concave End Set Screw Cup Point Grub Screw Internal Hex Socket Set Screw M2 M3 M4 M5 M6 M8

Attributes

Brand -
Category Standard Parts, Components & Industrial Consumables / Screws
Origin -
Material Alloy Steel
Strength Grade 12.9
Point Type Cup Point (Concave)
Drive Type Internal Hex Socket
Head Style Headless (Grub Screw)
Surface Finish Black Oxide
Available Sizes M2, M3, M4, M5, M6, M8
Thread Standard Metric Coarse
Application Securing collars, gears, and pulleys to shafts
Package Content Assorted Kit (100 pieces)

6 reviews

A

Anonymous

Mar 29, 2026

Rating: 5/5

Perfect for machinery repair

Needed specific concave end set screws for an old lathe repair. These fit the specs exactly. The internal hex is precise, allowing for good torque application without slipping.

A

Anonymous

Mar 28, 2026

Rating: 5/5

Exactly as described

Bought these for a custom bicycle build. The headless design is perfect for clean aesthetics where space is tight. No issues with quality or threading.

A

Anonymous

Mar 07, 2026

Rating: 5/5

Strong and reliable

I use these for securing motor shafts in robotics projects. The 12.9 grade ensures they don't shear under stress. Fast shipping and well-packaged.

A

Anonymous

Mar 06, 2026

Rating: 4/5

Good value bulk pack

Great assortment for the workshop. The black oxide finish looks professional. One star off because the M2 screws were slightly harder to find in the mix, but overall a solid purchase.

A

Anonymous

Mar 03, 2026

Rating: 5/5

Excellent hardness and fit

These grade 12.9 screws are incredibly strong. I used the M4 size to secure a timing pulley on my CNC machine, and they held perfectly without stripping the socket. Highly recommended for high-torque applications.

A

Anonymous

Mar 02, 2026

Rating: 4/5

Solid industrial quality

These are genuine high-tensile screws. The cup point digs in well to the shaft. Just make sure you use the correct Allen key size to avoid rounding the head.

5 FAQ

Q: What is the exact hardness rating of Grade 12.9?

A: Grade 12.9 alloy steel screws typically have a minimum tensile strength of 1220 MPa and a hardness range of approximately 39-44 HRC, making them suitable for high-stress applications.

Q: Can I get a VAT invoice for this purchase?

A: Yes, as mentioned in the product description, we offer special VAT invoices. Please ensure your company details are entered correctly at checkout or contact our billing support after purchase.

Q: Are these screws suitable for outdoor use?

A: While the black oxide finish offers some corrosion resistance, for prolonged outdoor or marine exposure, we recommend applying a thread-locking compound with anti-corrosion properties or choosing stainless steel variants if available.

Q: Does this kit come with an Allen key?

A: No, this specific assortment kit contains only the set screws. You will need to provide your own metric hex keys (Allen wrenches) corresponding to sizes M2 through M8.

Q: What is the difference between cup point and flat point?

A: A cup point (concave) has a small indentation that bites into the shaft for superior holding power and resistance to vibration. A flat point is used when you do not want to damage the shaft surface, offering less holding torque.

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