Carbon Steel Lock Nut, Zinc Plated Finish, Right Hand Threads, Self-Locking/Nylon Insert, Meets DIN 985, M4-0.70 Threads (Pack of 100): Amazon.com: Industrial & Scientific
M4 x 0.70 Coarse Thread DIN 985 Class 10 Nyloc (Nylon Insert Locknut) Standard Medium Carbon Steel Zinc Plated Pk 100: Amazon.com: Industrial & Scientific
1200pcs) DIN 982 M4 Self-Locking Hexagon Nuts, High Type A2 Stainless Steel, Ships Free in USA by Aspen Fasteners, ASSP098224: Amazon.com: Industrial & Scientific