Simpson 1/2" x 4" Hex-Head Stainless-Steel Sleeve-All Anchor SL50400HSSThe Simpson Strong Tie Sleeve All expanding anchors are pre assembled, expanding sleeve anchors for use in all types of solid base materials. This anchor is available in acorn, hex, rod coupler or flat head style for a wide range of applications. Model No. SL50400HSS Head Type. Hex Head Coating Material. Type 304 Stainless Steel Size (in.) 1 2 x 4 Bolt Dia. (in.) 3 8 Drill Bit Dia. (in.) 1 2 Wrench Size (in.) 9 16 TPI. 16 Max. Fixture Thickness (in.)