M1.6–M12 DIN916 Black Grade 12.9 Steel Hex Socket Allen Cup Point Set Screw Grub Bolt

M1.6–M12 DIN916 Black Grade 12.9 Steel Hex Socket Allen Cup Point Set Screw Grub Bolt

DIN916 black grade 12.9 steel hex socket cup point set screws (grub bolts) for high-strength shaft locking, pulley retention, and gear collar fastening. Grade 12.9 provides the highest tensile strength available in metric set screws — significantly stronger than standard grade 8.8 or 10.9. The cup point tip bites into the shaft surface for maximum holding force without through-drilling.

Key Specifications

Why Choose Grade 12.9 Cup Point Set Screws?

• Grade 12.9 strength — 1220 MPa tensile strength; ideal for high-torque shaft locking applications
• Cup point tip — bites into shaft surface for maximum holding force; prevents rotation and axial movement
• Black oxide finish — professional appearance; light corrosion resistance for indoor use
• M1.6–M12 range — covers miniature electronics to heavy industrial shaft locking
• DIN916 standard — interchangeable with ISO 4029 and ANSI B18.3 equivalent

Typical Applications

• Shaft collar and hub locking on motor shafts (stepper motors, servo motors, DC motors)
• Pulley, sprocket, and gear retention on shafts
• CNC machine tool holder and collet locking
• 3D printer motor coupling and pulley locking (GT2 pulley M3 set screw)
• Rotary encoder and potentiometer shaft locking
• Optical mount and precision instrument adjustment locking

Compatible With

Standard metric tapped holes M1.6–M12. Allen key sizes: M1.6=0.7mm, M2=0.9mm, M2.5=1.3mm, M3=1.5mm, M4=2mm, M5=2.5mm, M6=3mm, M8=4mm, M10=5mm, M12=6mm. Commonly used with: NEMA 17 stepper motor shafts (M3 set screw), GT2 timing pulleys (M3), shaft collars (M4–M8).

FAQ

Q: What is the difference between cup point and flat point set screws?
A: Cup point (DIN916) has a concave cup at the tip that bites into the shaft surface, providing high holding force. Flat point (DIN913) has a flat tip that distributes load without marking the shaft — used where shaft surface must be preserved.

Q: What set screw size do I need for a GT2 timing pulley?
A: Most GT2 timing pulleys for 3D printers use M3 cup point set screws (DIN916 M3). Check your pulley specification for the exact size.

Package Contents

• DIN916 black grade 12.9 steel cup point set screws (quantity and size per selected variant)