The making, shaping, and treating of steel for the manufacturing of the National Foundry electric eye is poured in-house to meet U. S. 1040 standards. Our Spectrolab facilities verify that these standards and codes are met. The eyes can be obtained for the application required for either 1, 2, or 3 strands as specified by the user. The threads on the eye vary as to the size of rod used. These threads are made according to National Course specifications. The eyes are coated with electric orange epoxy coating for maximum weather protection. They are also protected with a padded bag to prevent scuffing during shipping and delivery.
National Foundry’s anchor rod has the chemical analysis: U.S. ASTM A36 and A52950 certified steels. The rods vary in size and length according to users needs. One end of the rod is either threaded for the screw-on eye or welded for the weld-on eye according to clients required specifications. The opposite end of the rod is threaded to National Course specifications. The anchor rod between the threads is covered mastic asphalt, then contained within a plastic rod sleeve for cathodic protection against electrolysis, rust, and corrosion deterioration. It then slips through the guide that is welded on to the National Foundry concave dish anchor plate and plastic washer. Then it is threaded into the coupling nut that holds the unit in place.
The National Foundry concave dish electrical anchor bottom consists of U. S. A36 steel. The circumference and thickness gauge of the dish varies in size according to the application requirements. A pipe guide is welded on to the center of the anchor plate to facilitate the anchor rod in penetrating correctly through the plate onto the plastic washer and coupling nut, holding the plate on to the rod. The concave dish is then coated with a mastic coating. The design of the concave dish anchor plate is to obtain maximum holding power per cubic inch of soil compressed above it.
A plastic isolator washer is used between the plate and nut to isolate the electric current flowing from the eye to the ground. The plastic isolator washer is either made of black plastic nylon for the use with smaller anchor rods, or high impact polystyrene for the high-line anchor rods. In each case the surface area of the washer is two-and-half (2 1/2) times larger than the inside diameter, and is 5/8" thick.
The heavy cast coupling steel nut at the end of the anchor rod is manufactured at National Foundry of U. S. 1040 steel. They are then tapped and threaded National Course with the depth of threads to be twice the diameter of the rod to be used. They are then coated with a safety orange epoxy coating for maximum protection.
Suggested installation of the National Foundry concave dish electric anchor for optimum holding capacity is to install the anchors at a 90 degree vertical angle, since the weakest area on any anchor rod is the threads. This allows for more of the tension strength to come from the rod rather than just the threads. The maximum advantage of installing this anchor in a 90 degree vertical angle is you set a cylinder effect where you have more compressed soil weight per cubic inch from the plate to the top of the soil, thus giving it maximum holding power.