50 pcs) Metric DIN 985 M16X1.5 Nylon Insert Lock Nut Class 10 Steel: Hardware Locknuts: 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
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