12.9 hardness. Quality U.S. made hex head bolts and washers
When replacing the engine mounts in your older Mercedes, you might want to consider replacing the bolts that secure the engine mounts to the chassis, especially if they are rusty or damaged.
1972 to 1985 Rubber Engine Mount Attachment Bolts
$4.20
SKU:
GEG - 6MMEMBOLTS 
Product Details
Installation tip: use any soft-setting glue to secure the washer to the bolt head. You only need a dab of glue, but it will prevent the washer from falling off the bolt when you reach up to set it in place.
Typical rubber mount style used during this period.
