The Double Fold Self Locking Washer utilizes two asymmetric washers:both with low-friction inclined teeth and high-friction radial convex surfaces. When installed correctly (low-friction sides facing each other, high-friction sides contacting bolt/nut and workpiece), vibration-induced slippage between teeth triggers a wedge effect, increasing thickness to offset bolt loosening. Simultaneously, convex surfaces grip mating parts to prevent rotation. This dual-action mechanism combines friction differentiation, geometric amplification, and mechanical interlocking, maintaining clamping force under extreme vibration (-50°C to +300°C). Key applications include heavy machinery, transportation, and energy systems. Advantages over traditional washers include reusability (3–5 cycles), active vibration compensation, and no chemical adhesives. Proper torque (70–80% bolt yield strength) and directional alignment are critical for ISO/DIN-compliant performance.

An eye nut is a heavy-duty fastener combining a threaded shank and integrated ring, designed for lifting/rigging applications. Its structure features a durable alloy steel, stainless steel, or titanium body, forged for strength and heat-treated to enhance load-bearing capacity. Surface treatments like galvanization or passivation improve corrosion resistance. Available in sizes from M6 to M64, it supports vertical and angular loads (up to 45°) when installed correctly via full thread engagement and alignment washers. Widely used in construction, marine, aerospace, and manufacturing, it ensures safe handling of machinery, structural components, and equipment. Critical safety practices include adhering to workload limits (e.g., 1.2 tons for M20), avoiding lateral stress, and routine inspections for wear. Eye nuts offer versatility, durability, and ease of use, outperforming alternatives in repetitive load scenarios.

A rivet nut (blind nut) is a tubular fastener that creates strong, reusable threads in thin or single-sided materials. It combines a threaded interior with a knurled/smooth exterior and a flange for stability. Common variants include open-end, closed-end (sealed), hexagonal (anti-rotation), and grooved types. Made from steel, stainless steel, aluminum, or brass, they are often zinc-plated or anodized for durability. Rivet nuts are widely used in automotive, aerospace, electronics, and construction to mount panels, fixtures, or components securely. During installation, a tool pulls a mandrel (a threaded rod inside the nut), causing the body to deform and grip the material. The mandrel is then removed, leaving undamaged threads for bolts. Unlike self-tapping screws, rivet nuts enable single-side access, reusable threads, and compatibility with metals, plastics, and composites, making them essential for lightweight, high-strength fastening in modern engineering.

Standoffs (self clinching standoffs) are threaded fasteners permanently installed into thin metal sheets via pressing, eliminating welding. Types include blind/through-hole, countersunk, flange, grounding, and double-ended variants. Materials range from stainless/carbon steel to aluminum, with coatings like zinc or nickel for durability. Key features include knurled bases and hexagonal heads. Installation requires precise pre-drilled holes and hydraulic pressing. Widely used in electronics (PCBs), automotive, and aerospace for secure, vibration-resistant assemblies. Common metric sizes: M3–M6, with shank/hole diameters specified per industry standards (e.g., M3: 5.4mm hole). Ideal for space-saving, high-strength applications.

Standoff spacers are threaded fasteners that separate and secure components in assemblies, ensuring spacing, stability, and electrical isolation. Made from nylon, aluminum, brass, or stainless steel, their material selection depends on conductivity, weight, and environmental needs. Surface treatments like anodizing, nickel plating, or chromate coatings boost durability. Available in hex/round shapes and thread configurations (male-female, female-female), common sizes include metric (M3–M6) and imperial (#4-40–#6-32) threads, with lengths from 3mm to 20mm. They are widely used in PCB mounting, industrial machinery, aerospace, and consumer electronics. Proper installation requires material/thread compatibility, component alignment, and avoiding over-tightening. Best practices include addressing thermal expansion, vibration resistance, and anti-corrosive coatings for harsh conditions. Optimizing spacer selection ensures reliable, organized assemblies across engineering applications.