Flat Head/Martini Bolts are mostly used with small feet and shallow bolt depths. Button head molds are mostly used on DIY wood holds. All bolts are manufactured with a unique Cold-Forging technique that results in greater strength, higher fatigue resistance, and threads that last! Using high-quality bolts is critical if you want to get the longest life possible out of your t-nuts. Use Alloy Steel bolts indoors, and Stainless Steel if you’re outside in a high humidity area. These are not fully threaded bolts. If you would like to order in bulk to save money you can buy Bulk Bolts!