Adult Caucasian male fingers turn bolt clockwise onto hexagonal screw, close up

fastener screw bolt shallow depth of field extreme close up external thread screw thread bolt mechanical torque metal closeup internal thread fingers nut close up cylindrical tighten hexagonal stainless connection secure steel tool helical structure held together silver mating surface object align hole clockwise turn force carbon twist fasten design match shaft shape onto together advance join adult male caucasian mating