【100 Pcs M4 x 16mm Hex Socket Button Head Cap Screws + 1 Pcs Hex Key Come In a Plastic Storage Box】
✔ Contains 100 Pcs M4 x 16mm hex socket button head cap screws
--Meets/exceeds: ISO7380
--Thread size ( diameter ): 4 mm
--Thread Pitch: 0.7 mm
--Thread Length: 16 mm ( Range: 16.00 ± 0.35 mm), Total Length ( includes head ): 18.08 mm ( Range: 18.08 ± 0.48 mm )
--Screw head style: button head, head diameter: 7.42 mm( Range: 7.42 ± 0.18 mm), Head Height: 2.08 mm ( Range: 2.08 ± 0.13 mm)
--Screw drive style: hex socket drive, also known as internal hex drive, hex size: 2.5 mm --Made of alloy steel 40Cr, black oxide finish, high strength and anti-rust
--Strength grade of screws : 12.9 Grade, hardness: HRC 39-44, tensile strength: 1220 N/mm²

✔ Contains 1 Pcs hex key to drive these screws conveniently and easily
--Hex size: 2.5 mm
--Made of chrome-vanadium steel, nickel plated, higher strength, anti-rust
✔ Easy to store: 100 Pcs M4 x 16mm hex socket button head cap screws and 1 Pcs Hex Key come in a plastic storage box, organized conveniently and easily

[ Package Contains ]
M4 x 16mm-----100 Pcs
Hex Key------1 Pcs

[ What is Hex Socket Drive ]
Hex Socket Drive, also known as Internal hex drive, have a hexagonal hole in the center that requires an Allen key, also known as a hex key or Allen wrench
[ What is Button Head ]
Button head is similar to standard pan head screws but have a curved top