Products Description

Our Black Set Screws, also known as grub screws or socket set screws, are precision fastening hardware manufactured strictly to DIN916 international standard. Featuring internal hex drive and cup point design with black oxide finish, these set screws are designed for locking positioning, axial fixation and anti-loosening assembly between shaft, hub, gear and mechanical components. Without external head protrusion, they achieve flush installation to avoid interference with surrounding moving parts, widely adopted for mechanical equipment, automation fixtures, instrumentation and machinery assembly.

Third-party inspection available

Core Basic Specifications

Item	Parameter Details
Executive Standard	DIN 916 (Cup Point Socket Set Screw)
Surface Treatment	Black oxide finishing (blackened anti-rust coating), improves wear resistance and basic corrosion resistance
Main Raw Material	High-quality carbon steel, alloy steel
Strength Grade	Grade 4.8, Grade 5.8, Grade 8.8
Drive Type	Internal hexagon socket drive for stable torque transmission
Tip Style	Cup point (concave end), fits positioning pits on shafts for firm locking
Size Range	Complete metric sizes from M1.6 to M24, customizable length per customer demand

Material & Strength Performance

Grade 4.8 Carbon Steel: Cost-effective conventional option, sufficient clamping force for light-load general machinery, daily equipment assembly, low-frequency static positioning.
Grade 5.8 Medium Carbon Steel: Balanced tensile strength and toughness, suitable for medium load mechanical locking, moderate vibration working environments.
Grade 8.8 High-Strength Alloy Steel: Quenched & tempered high hardness structure, outstanding shear resistance and anti-loosening performance, ideal for heavy load, high vibration, continuous dynamic operation industrial equipment.

Black oxide surface treatment forms a dense protective film on the screw surface, resisting oxidation and slight rust during indoor dry working conditions, while reducing friction during tightening and disassembly.