Socket Flat Countersunk Head Cap Screw, 1/4-20 x 1/2", Alloy Steel, Black Oxide, Hex Socket (Quantity: 100) Coarse Thread, 1/4 inch Allen Bolt, Length: 1/2 inch, Full Thread: Amazon.com: Industrial & Scientific
Countersunk bolt 10 x 35 mm with flat head for climbing holds