Survey caps for rebar with SureGrip plastic insulators ... another first from Berntsen, makes good sense. Fast and easy installation helps you lower costs in the field. Feedback from our customers told us that:
a good rebar cap would not "wobble" when tapped on the rebar. Berntsen's rebar caps have a deep hex socket and are orbital forged from 6000 series aluminum ... a better design than a simple tapered "cone" socket, and a significantly stronger aluminum alloy than 99% pure aluminum other manufacturers use for survey caps. The 6000 series aluminum used in Berntsen rebar caps is the same alloy family used for the rods in our rotating rod monument system. When rods are driven to refusal, they have to be super tough. So are Berntsen rebar caps.
a good rebar cap must virtually eliminate dis-similar metal corrosion. Surveyors know that aluminum attached directly to rebar or pipe would loosen in a short period of time. This confirms metallurgical theory. Aluminum is less "noble" than steel, and an electrical current will actually flow from the aluminum (+) to the steel (-). Corrosion will occur in the annode (+) area of this battery like combination of metals in the presence of moisture (air or soil acting like an electrolyte).