The body of the anchors is also corrosion resistant

3/4-10 x 7 1/2 Socket Cap Screw Alloy

1 1/8-7 x 11 Socket Cap Screw Alloy

Typical hardness on diameters 1/4 to 2 1/2 inches is HRC 33-39

1 1/4-7 x 11 Socket Cap Screw Alloy

1/2 x 2 3/4 Mushroom Spike Zinc Plated (50) Phillips Flat Machine Screws Type F Zinc Plated The body of the anchors1 2 x 2 3 4 Mushroom Spike Zinc Plated (50) . The Spike anchor is a patented, one piece, tamper proof, vibration resistant anchor for use in concrete, block, brick or stone. Several head styles and anchor materials are available. The Spike anchor is formed with an "s" shaped configuration at the working end of the anchor to create an expansion mechanism. Since the anchor is pre expanded, there is no secondary tightening operation required which