Studs | Self Clinching Studs - Heavy Duty Flush Head, Concealed & Broaching Studs | Features & Applications

Overview

Even simpler in form than general threaded nuts, a threaded stud is a permanent fixture with external threads which can be mated with a loose nut. The attachment side includes anti-rotation features such as knurls or a hexagonal head, informing whether round or hexagonal bar stock is used. Variations are available based on the material into which the stud is installed and the loading specifications of the application. This results in different features for flush heads, concealed heads, and extra strength studs.

Application

Focusing on one attachment style helps narrow the range of applications for a fastener as versatile as a stud. For example, concealed heads help satisfy cosmetic requirements in consumer electronics, such as video game consoles or other entertainment systems. A shallow, blind hole is milled into a metal panel and accepts the undercut of the concealed head while the knurls displace material into the undercut upon installation. This provides strong threads for mounting internal components while leaving the external surface untouched. It also aids in waterproofing and sealing applications that aim to keep liquids or dust from infiltrating the interior of the assembly. Clinch studs can even serve as male standoffs when paired with a metal or plastic spacer.

Three varieties of threaded studs with broaching or self-clinching attachment features

A self-clinching stud mounted in a blind hole

The concealed head stud can clinch into a panel without disrupting the cosmetics of the opposing side.

A sheet metal housing with four studs clinched into blind holes as well as a spacer used to make a male standoff

Cross-section of console housing with studs mounted directly to the enclosure.

Alternative Solutions

Given the cosmetic requirements for the external surface, any through-hole alternative is not feasible. While a welded stud eliminates milling in the panel entirely, the associated risks of weld spatter and asymmetry could lead to tolerance or quality problems within the assembly. However, one limiting factor of a concealed head stud is the minimum panel thickness required for a strong, self-clinching attachment. Thinner panels can use through-panel studs or bolts for greater strength while satisfying the cosmetic requirements by using a plastic outer shell. This allows for more aesthetic freedom of design, as seen in many video game consoles.

Common Attachment Technologies

While welding, self-clinching, and press-fit broaching studs are common, surface mounted (SMT) studs are rare since they would rely on the bond of the reflowed solder during loading rather than any geometric interference in PCB mounting. Another attachment method that functions independent of panel material is swaging. In this method, the stud is deformed rather than the panel to secure itself with a clamping load. Similarly, within the family of rivet nuts is the rivet stud, with a collapsible barrel for retention within a panel.