Advantage is that 1) the fastening force is relatively large, 2) and it can be operated by using an Allen key so that easy to install, almost used in a variety of structures, 3) The appearance is relatively beautiful and tidy. 【☞】 Product name: M6 x 6-11/16 Inches Socket Cap Bolt; Snapklik.co : binifiux 20pcs 6 X 15 Black Rivet Countersunk Socket Cap Allen Bolts Rivet... binifiux Kit surtido de 100 tuercas hexagonales 6 de cabeza Allen para uebles de cuna... [About Socket Cap Screws:] The hexagonal head socket cap screw is widely used among all kinds of screws and is relatively high in requirements. The disadvantage is that the fastening force is lower than the outer hexagon, and the repeated use of the inner hexagon is easy to damage. Buy Bolt Base (6) 6 x 60 Black 12.9 Grade High Tensile Hex Socket Cap screws Self Colour 4 Pack High Strength Cap Bolts M6 X 50mm Unbrako Socket Head Csk Screw Part Thread In Black Oxide - ISO 10642 (DIN 7991) - Westfield Fasteners Ltd M6 X 170mm Black Alloy Steel Bolts