#12-24 x 2" Unslotted Indented Hex Washer Head Tek 5 screws, Zinc Plated Features:Pre-assembled Bonded NEO-EPDM metal backed washer creates leak proof seal.Self-Drilling for metal to metal applicationsHex washer head provides excellent driving stabilityPrecision cutting drill point delivers high performance with less physical effort.Low corrosion resistance Details:Bonded Washer: 9/16" O.D.Head Type: Unslotted Indented Hex Washer HeadDrive Size: 5/16"Thread Diameter: #12Threads Per Inch: 24Length: 2"Point: #5 Self-DrillingQuantity: 2,000 pcsWeight: 38 pounds [approx.] Material Application:Attaches metal to metalDrill Capacity: .125 - .500Drill Speed: 1500 RPM Specifications:Bonded washer creates leak proof sealMeets ASTM C 1513 for cold-formed steel framing connectionsMeets F.I.P.-1000.7 for torsional strength & drill speedMeets SAE J78 for performance & dimensional specificationsMeets ASTM A 510 for carbon steel manufacturingMeets ASTM F1941 for corrosion resistanceZinc Plated Zinc plated is a plating that is applied electrically to fasteners that prevents oxidation of steel by forming a protective barrier. Not recommended for ACQ Treated Lumber.