KNUCKLE THREAD DIN 20400 This thread is used in the mining industry for increased bearing depth. Bolt Thread Minor Diameter mm Bolt Tapping Drill Size mm Pitch mm Nut Thread Minor Diameter mm Nut Tapping Drill Size mm Rd 10 6,700 3,000 10,300 7,000 Rd 12 8,700 3,000 12,300 9,000 Rd 14 10,700 3,000 14,300 11,000 Rd 16 11,600 4,000 16,400 12,000 R..