Slotted Drive Headless Set Screw

In precision assembly and machinery construction, the slotted drive headless set screw serves as a foundational component for securing collars, gears, and pulleys onto shafts without protruding heads. This fastener sinks entirely into a tapped hole, using a simple straight slot machined across its end face to accept a standard flat-blade driver. When your design calls for an entirely flush surface with no socket engagement, you may also consider our Flat Slot No Head Threaded Fastener, which eliminates any raised boss and sits completely even with the mating surface, ideal for tight-space installations where even a few thousandths of an inch matter. In contrast, applications requiring a shallow blind thread engagement without penetrating through the workpiece often rely on the Single Slotted Blind Head Machine Screw—a close relative that provides a clean, closed-end termination while still offering the same flat-slot drive simplicity. Both variants share the core advantage of a minimal tooling interface, yet the headless design remains the workhorse for high-volume axial and radial locking tasks where repeated adjustments are common and the fastener must remain completely concealed within the assembly.

Our Slotted Drive Headless Set Screw is manufactured under tightly controlled tolerances to meet ANSI/ASME B18.3 and corresponding DIN standards, ensuring consistent thread fit and slot geometry across thousands of cycles. Each screw is formed from heat-treated alloy steel and finished with a black oxide coating that resists corrosion while providing a mild lubricity during installation. For corrosive environments, we offer A2 and A4 stainless steel variants with comparable hardness. The slot depth and width are precisely broached to reduce cam-out and stripping, even when higher seating torques are applied. Point configurations include flat, cone, cup, oval, and half-dog styles to match the specific holding requirement—whether digging into a soft shaft, centering in a pre-drilled dimple, or providing non-marring contact on polished journals. The following breakdown of standard dimensions and materials will help you select the ideal part for your assembly.

Standard Material & Finish Options

• Alloy Steel – Min tensile strength 180,000 psi, black oxide finish
• Stainless Steel A2 (304) – Moderate corrosion resistance, clean passivated surface
• Stainless Steel A4 (316) – Enhanced chloride resistance for marine and chemical use
• Brass – Non-magnetic, decorative, suitable for electrical insulation
• Nickel-plated brass – Additional tarnish resistance and aesthetic appeal

Point Style Descriptions

• Flat Point – General purpose, minimal shaft damage, often used with a matching flat on the shaft
• Cone Point – Penetrates the shaft material, provides high holding force under vibration
• Cup Point – Most common; the sharp edge digs into the shaft, offering strong resistance to rotation
• Oval Point – Rounded tip reduces marring on soft or finished shafts
• Half-Dog Point – A reduced-diameter tip fits into a drilled hole or keyway for positive locking