The M6 nut is used in many applications, especially on classic motorcycles; in some case to secure the cylinder head on the Cub derived engines. In this instance you may wish to purchase this Copper Seal Washer at the same time.
The M6 nut you may wish to order to compliment this washer:
90230087000
Please make sure part numbers ordered are compatible with your model. Order ALL the fastener components required at the same time and save money on shipping costs and avoid frustration later in your workshop or garage when you find a vital part missing!