5-16 18x1 Inch Grade 5 Indented Hex Head Sems Bolt with Conical Washer Pack of 50 Made in USA

Material and performance screw: SAE J429 (5:1) Washer: SAE 1045-1085 RC 40-48. Black Zinc Finish. .0002 Min. Zinc with 4-hour bake and high corrosion hex-free black chromate. Conical washer No. 96017000 .620-640 0D x .074-.087 THK W/.016-.026 crown height. .013-.033 Radius under the head of the screw. Made in the USA. Product is warranted for 30 days after the date of purchase and will be replaced free of charge, if the product is proven to have manufacturing defects that caused failure, and has been used as intended under normal conditions. Proof of purchase required. Please allow 4 weeks turnaround time for a replacement.