Allen Hex Drive Size: 5/32 inch (Included a hex wrench); Package Contents: 20 PCS Thread Size: 1/4-20; Thread Pitch: 20 TPI; Head Diameter: 0.43 inch; Head Height: 0.1 inch; Find more details in the second picture Feature: The head has a domed, button-like shape that is lower than conventional socket head cap screws; This allows it to sit flush or below the surface when installed Material: The screws are made of 304 stainless steel 18/8; Excellent toughness; Good corrosion resistance; High strength and durability; Heat Resistance Applications: Their low-profile, decorative appearance makes button head screws suitable for applications where a flush finish is desired, such as electronics, automotive, furniture, and machine assembly. The socket drive also provides tamper resistance