M6 x 1.00 Coarse Thread DIN 985 Class 10 Nyloc (Nylon Insert Locknut) Medium Carbon Steel Yellow Zinc Plated Pk 50: Amazon.com: Industrial & Scientific
M6 x 1.00 Coarse Thread DIN 985 Class 8 Nyloc (Nylon Insert Locknut) Standard Medium Carbon Steel Black Oxide Pk 1500: Amazon.com: Industrial & Scientific