Features 1、Made of high quality brass, it is of high hardness and good durability. 2、No deformation under great pressure. 3、Resistant to wear, oxidation and corrosion, long service life. 4、Knurled surface makes nuts embed installed object tightly and stably. 5、High precision threads is compatible with corresponding screws. Specification Features: Made of high quality brass, it is of high hardness and good durability. No deformation under great pressure. Resistant to wear, oxidation and corrosion, long service life. Knurled surface makes nuts embed installed object tightly and stably. High precision threads is compatible with corresponding screws. Specification: Material: Brass M4*6*6.3 20pcs M4*7*6.3 20pcs M4*8*6.3 20pcs M4*10*6.3 20pcs M4*12*6.3 20pcs M4*16*6.3 10pcs M4*20*6.3 10pcs Weight: Approx. 22-39g Package list: 1 * Pack of M4 Blind Hole Knurled Nuts Package List