title = "Mechanical Fastening: Bolts, Rivets, and Clinching"

content = """
Mechanical fastening joins metal components using discrete mechanical elements—bolts, nuts, screws, rivets, and clinch fasteners—without applying heat or filler material. At Ridgecrest Metalworks, mechanical fastening is used where disassembly for maintenance is required, where dissimilar metals cannot be welded, or where heat-sensitive components must be joined.

Bolted connections use threaded fasteners (bolts with nuts, or cap screws into tapped holes) to clamp joint members together by pre-tensioning the fastener. Bolt grade (SAE Grade 5, Grade 8; metric Class 8.8, 10.9, 12.9) determines tensile strength, proof load, and minimum yield. Torque specifications for tightening must be followed from the engineering drawing or the applicable standard (ASME, SAE); undertorquing leaves the joint loose and subject to fatigue loosening; overtorquing risks fastener fracture or thread stripping. Torque wrenches must be calibrated. For critical structural joints (AISC-specification structural bolt connections), high-strength bolts (A325, A490) may require installation by turn-of-nut or direct tension indicator methods to verify minimum clamping force without relying on friction-affected torque values.

Solid rivets are permanent fasteners placed in a pre-drilled hole and upset (deformed) at the tail to form a head that clamps the joint. Hot riveting (for heavy structural and boiler work) uses heated rivets that contract on cooling, creating high clamping force. Cold riveting is used for light sheet metal. Blind rivets (pop rivets) install from one side only using a pull mandrel tool, making them essential for assemblies where access to both sides is impossible.

Self-piercing rivets (SPR) are increasingly used for sheet metal assemblies. The rivet is pressed through the top layer and into (but not through) the bottom layer, forming a mechanical interlock. No pre-drilling is required. SPR is fast, automatic, and used for joining high-strength steel and aluminum sheets including dissimilar metal combinations.

Clinching (also called press-joining or Tog-L-Loc) joins two or more metal sheets by pressing a punch into the upper sheet, forcing both sheets into a die cavity that forms an interlocking button joint. No fasteners, heat, or adhesive is required. Clinching is low-cost, produces no fumes, and is suited to thin-sheet assemblies in high-volume production. Joint shear strength is adequate for sheet metal enclosures and panels.
"""

version = "0.0.1"
