The slots are for the insertion of a cotter pin to secure the nut when used with a drilled shank fastener

TEKS® Self Drilling Screws feature a Climaseal® coating for superior corrosion protection in even the most extreme outdoor environments

Featuring a tan Quik Guard® coating for excellent corrosion resistance

1/2-13 x 4 Grade 5 Hex Cap Screw Zinc Plated Domestic USA (150)

3/4-10 x 3 3/4 Socket Cap Screw Alloy

5/8 x 5 Titen HD® Heavy-Duty Screw Anchor 304 Stainless Steel (10) 7/16-20 Grade 8 Hex Cap Screws Plain - Domestic USA The slots are for theThis 10 pack of 5 8 x 5 Titen HD Heavy Duty Screw Anchors is made of corrosion resistant 304 stainless steel, providing maximum strength and durability for your projects. The anchors are easy to install and hold up to 2,000 lbs, making them ideal for heavy duty applications.