MRO Tools KHNK-FW3/16 Super Long Grip Hex-Nut Cleco Fasteners. MRO Tools Super Long Grip Hex-Nut Cleco Fasteners (KHNK) are designed to be operated with a pneumatic power tool and are best suited for high-production settings that require fast, consistent and uniform clamping force. MRO Tools Super Long Grip Hex-Nut Cleco Fasteners feature a free-wheeling design that allows it to back completely off while still remaining intact with the body. MRO Tools Super Long Grip Hex-Nut Cleco Fasteners work well with all types of metallic and composite materials. MRO Tools Cleco Fasteners are widely used in automotive, racing, and aircraft sheet metal repair. MRO Tools Cleco Fasteners are designed to temporarily fasten multiple sheets of material together before the pieces are permanently joined. MRO Tools Cleco Fasteners are a simple and inexpensive alternative to competitive fasteners and are available in various lengths and strengths to accommodate different processes.