18-8 / 304 Grade Stainless Steel Solar Panel Mounting  Nuts.

• A Finish Hex Solar Nut is Most Commonly Used with Stainless Steel Bolts and Screws Sized Over 1/4-20 Thread.
• Solar Panel Mounting Heavy Hex Finish Nuts are Stronger and Thicker than Regular Finish Hex Nuts.
• Solar Keps or Solar K-Lock Nuts are for Use Where you Need a Locking Contact Under the Nut.
• Solar Bracket Nyloc Nuts are a Friction Security Hex Nut that has a Nylon Plastic Collar Center and Grabs the Thread of a Screw or Bolt and Causes Friction Between the Threads and Nut. Other Common Names Include Solar Nylock, Elastic Stop Nut, Polymer Insert Lock Nut.
• A Solar Serrated Hex Flange Nut is a Perfect Blend of Both a Locking Nut and a Hex Nut. When Used Where Space Permits on your Solar Panel Mounting Hardware, it Allows High Strength of Full Thread Surface Contact and a Degree of Vibration and Impact Resistance While also Allowing Exacting Torque Specifications to be Achieved.