What Stainless Steel Grade Is Used in Crete-Flex SS4 Fasteners? Crete-Flex SS4 masonry fasteners are available in Type 410 or 316 stainless steel, depending on the product style and application requirement. By Marsh Fasteners|2026-06-29T04:42:41-04:00June 29, 2026|Crete-Flex SS4 Masonry Fasteners 2|