Berntsen offers the following styles of bronze concrete survey markers for use in concrete or rock:
"C" style (US Army Corps of Engineers Type 1 Disc) has the classic 2 3/4" (50.8mm) long split-style tapered stem. It is available in 3-1/2" (89mm) or 4" (102mm) diameters. Orbital formed from solid unleaded silicon bronze bar.
For smaller marks use the "CD" style 2" (50mm) diameter marker has a 3 /4" (19mm) diameter x 2" (50mm) long stem and is notched to hold firmly in concrete or rock. Orbital formed from solid unleaded silicon bronze bar. It is also available as a leveling mark with a raised datum point (with recessed center) for precise monitoring (model CD2LB).
The "RT" style is a variation on the concrete disc theme and is available in a 3-1/2" (89mm) diameter. The RT1 offers more resistance to twisting and features four legs. Orbital formed from solid unleaded silicon bronze bar.
The CAPMAG ceramic magnet can be used with concrete markers to assure easy detection of the mark with a magnetic locator. Dimensions are 1/2" (13 mm) in diameter and 1/4" (6 mm) long. The magnet can be located up to 6 to 12 inches deep with a magnetic locator, depending on soil conditions.
The C4DRL countersink drill bit is made specifically to perfectly recess this C4FB concrete marker in existing concrete.
Brass has been used in the manufacture of survey monuments and markers for many years. Iron pipe monuments with brass caps were used by federal government surveyors as early as the first part of the 20th century. Certain brass alloys, notably those with a high lead (a hazardous material) content, equal or greater than five (5) percent, are now viewed as archaic metals. Alloys that are typically used in survey monument components were Leaded Semi-Red Brass 81-7-9 (7 percent lead) and Leaded Red Brass 85-5-5 (5 percent lead). Few customers require these alloys for any reason other than tradition.
Berntsen’s Better Way
Berntsen pioneered the introduction of non-leaded brass alloys for survey monuments and markers in the mid-1980’s. Through our continued research and testing we have found that brass or bronze alloys containing high amounts of coppers, provide the best characteristics in corrosion resistance, strength and durability. We now exclusively use silicone bronze alloy (97 percent copper, 2 percent silicon) for our cold forged survey markers and caps. In an independently conducted test, Berntsen’s silicon bronze cap was found to have essentially no corrosion after 240 hours of salt spray per ASTM B-117-16.
C4FB Concrete Utility Marker Installation Instructions