5/16" Black Screw Thread Protectors fit 5/16" screws and bolts. Simply slide over the threaded end of the screw or bolt. These Screw Thread Protectors are 1" long and can be cut shorter. Functions as a Thread Protector, Mask (for painting), Insulator, Decorator, Seal or to Color Code. Made from soft and flexible material called "75 durometer PVC". Available in Black. Bulk available.