Abstract: A sectionalized attachable rod survey monument of the type which is driven into the ground has a lower anchor pilot rod section and an upper rod section made of a solid aluminum alloy. An axial hole is drilled in the upper end of the pilot rod section and the lower end of the upper rod section to accept a stainless steel roll pin, and the two rods are separated by a stainless steel spacer washer. The spring pin becomes compressed when it is inserted into the holes in the ends of the rods and holds them together. The rods cannot physically be pulled apart under normal use; but when the upper rod is mechanically disturbed, such as when it is hit by road equipment or vandalized, the rods separate from one another. A permanent magnet is carried in the bottom of the hole in the lower pilot rod to permit detection of the marker location whenever the upper rod does become separated from the lower pilot rod.

Abstract: A survey monument of the type adapted to be driven into the ground includes at least first and second elongated cylindrical rod sections. The two sections are connected together by a threaded connector turned into threaded bores at the upper end of the first rod section and the lower end of the second rod section. The lower end of the first rod section is terminated by a conical penetrating point and a pair of flukes, formed by stamping them out of the first rod section, are located intermediate this point and the upper end of the first rod section. These flukes are oriented with respect to the axis of the rod sections to cause the sections to rotate about their axis in a direction to tighten the threaded connection of the two rod sections as the sections are driven into the ground.