SAE washers provide a standard bolt size inside diameter with a smaller O.D.
SAE washers are ideal where washer space is limited.
SAE sizes are designated by the bolt diameter they are intended to fit.
Bare finish fasteners have low corrosion resistance and are a good choice for indoor and industrial applications.
If there is an "(S)" in the part name, it indicates that it has a smaller O.D, compared to the "(L)" which indicates that it has a larger O.D
For the product numbers that are sold by weight, 5lbs or 40lbs the individual pieces that are contained within the package are approximate due to manufacturers making some flat washers/lock washers slightly thicker, or thinner.