• Knurled thumb screws M6 x 35 mm, male metric thread grip knobs. • Carbon steel hand bolts, black fasteners for furniture, electronics, and machines. • Use: fix and control machinery, musical instruments, furniture cabinets. • Material: carbon steel with zinc-plated surface, plastic head. • Quantity: 30 knurled screws per package. • Easy to use: no tools needed, simply tighten or loosen by hand.