12.9 grade US imperial UNC set screws are high-strength industrial fasteners designed for positioning, locking, and stopping applications in machinery. Covering key UNC thread sizes #8-32, #10, and #12-24UNC, these headless hex socket stop screws are fully compatible with American-standard equipment, making them ideal for heavy machinery, automotive assemblies, tooling fixtures, and precision mechanical setups requiring reliable load-bearing and anti-loosening performance.
Crafted from heat-treated high-grade alloy steel, the 12.9 grade rating delivers exceptional tensile strength, hardness, and wear resistance—outperforming standard grades in high-torque and heavy-load environments. The headless design enables flush mounting without protrusions, avoiding interference with moving parts. The internal hex socket drive ensures precise torque control during installation, while the UNC coarse threads provide strong engagement with mating components, reinforcing locking stability and long-term operational reliability.
Core Features & Advantages
12.9 grade alloy steel for superior high-strength, hardness, and wear resistance
UNC thread sizes (#8-32, #10, #12-24UNC) compatible with US imperial equipment
Headless design for flush mounting, avoiding interference with moving machinery parts
Hex socket drive for precise torque control and efficient industrial installation
Dual function as set screw and stop screw, ideal for locking/positioning applications
