304 stainless steel 18-8, high hardness, corrosion resistance, can be used in humid environments, and do not worry about rust. | Used widely in the home and office appliance, communication equipments, ship assembly and other machinery industry. | Thread Diameter: 1/4"; Thread Type: 20 tpi Coarse Thread (Standard) ;Screw Length: 2-1/2" | Package Included: 8PCS Bolts + 8PCS hex nuts + 8PCS Flat washers+ 8PCS Lock washers | High customer satisfaction, if you are not satisfied with the product, you can always send us an email, provide you with satisfactory service in the first time, you can also get a full refund, please rest assured to buy.