Ruland manufactures straight bore rigid couplings with precision honed bores. Honing ensures collinearity and reduces the likelihood of the coupling introducing misalignment into the system. All clamp type hardware is supplied with proprietary Nypatch anti-vibration coating. Nypatch is a 360-degree nylon-based coating applied around several threads of the screw. It provides for even seating of the screw, prevents galling, and allows for repeated screw installations. Nypatch saves end users considerable time in assembly as no additional screw treatment is necessary.
Ruland rigid couplings are available in a variety of materials for mixers including 1215 lead-free steel, 303 and 316 stainless steel, and aluminum. Steel is the most common and available with a proprietary black oxide finish for smooth screw installation and a fine glossy finish. It is well suited for most industrial applications such as large volume paint mixers. Stainless steel types are used in food and high corrosion chemical mixing applications. The grade of stainless used is largely determined by the corrosiveness of the environment and regulatory requirements. Ruland uses hardware of like material to ensure consistent corrosion resistance. Aluminum is not commonly used, however could be desirable if low inertia is required. Ruland manufactures rigid couplings in sizes from 3 mm (1/8 inch) to 50 mm (2 inches).