Crete-Flex® Phillips Flat Head 410 Stainless Steel Concrete and Masonry Fastener Print The Crete-Flex anchor is a 410 stainless steel screw anchor for light to medium duty applications in concrete and masonry block base materials. Crete-Flex anchors utilize more robust threads for enhanced thread engagement and “V” notches for efficient tapping. These features provide reduced installation torque and increased performance. Crete-Flex anchors feature a Stalgard coating and provide enhanced corrosion resistance over carbon steel fasteners. Read Less