Flat Slot No Head Threaded Fastener

Flat Slot No Head Threaded Fasteners are an integral component in advanced mechanical assemblies where a seamless, flush finish is critical for both function and safety. These fasteners eliminate external protrusions, reducing the risk of snagging and interference in compact machinery, medical devices, and precision optical equipment. In our comprehensive line of headless fastening solutions, we also feature the Slotted Drive Headless Set Screw, which is widely used for axial positioning and locking applications, and the Single Slotted Blind Head Machine Screw, tailored for blind-hole setups requiring a single-slotted engagement. Each product in this family undergoes stringent manufacturing processes to ensure impeccable thread geometry, precise slot dimensions, and consistent material properties across every batch.

The Flat Slot No Head Threaded Fastener delivers exceptional holding power while maintaining a completely flush profile within the tap bore. Its design relies on a flat, precisely milled slot that accepts standard flat-blade drivers, simplifying installation without the need for specialized tooling. The cold-rolled threads provide superior fatigue resistance compared to cut threads, enabling repeated assembly cycles in demanding industrial environments. This fastener is available in a wide spectrum of materials, including 18-8 and 316 stainless steels for corrosion-prone settings, 4140 alloy steel for high-stress applications, and naval brass where electrical conductivity or non-sparking properties are required. Thread forms span ISO metric coarse and fine pitches from M1.6 to M24, as well as unified UNF and UNC series from #0-80 to 3/4-16. Custom diameters and non-standard lengths are available on request, and all units are supplied with a certification of conformity to relevant ASTM, ASME, and ISO standards.

Key Performance Attributes

• True headless geometry enables complete sub-surface installation
• Flat slot interface compatible with simple flat-head screwdrivers
• Thread rolling enhances tensile strength up to 180,000 psi (1241 MPa)
• Dual thread standards: metric ISO 68-1 and inch-based ANSI/ASME B1.1
• Material options: stainless steel (304, 316), alloy steel (Grade 10.9, 12.9), brass, titanium
• Surface treatments include black oxide, zinc plating (trivalent chromate), passivation, and dry film lube
• Class 2A/3A thread fits available for precise torque-tension relationships
• Temperature range from -50°C to 300°C depending on material and coating

Standard Dimensional Data

All flat slot no head threaded fasteners are subjected to 100% dimensional inspection, and lot testing covers hardness, tensile strength, and thread fit. Packaging uses VCI material to preserve surface integrity during transit. For volume OEM requirements, we offer custom labeling, partial threading, and specialized surface coatings to match exact application needs.