Assortment box of 320 Imperial - UNC steel nuts. Manufactured to DIN 934. 1/4"" TO 1/2"" - 1/4""UNC (x120), 5/16""UNC (x120), 3/8""UNC (x50), 1/2""UNC (x30). STORAGE BOX - Supplied in a partitioned box. COARSE THREAD - Imperial UNC nuts designed for use with UNC Bolts and studs. HIGH QUALITY - Manufactured to DIN 934.