Mechanical Face Seals have been utilized with outstanding success in transmission, pumps, axles and drive machines. The special cast iron material has provided extra-ordinary wear-resistant solutions for a variety of demanding applications such as construction machinery, agricultural equipment, mining machinery, drive machines for tracked vehicles and many other applications. MDF type has an elastomeric diamond-shaped cross sectional secondary sealing element instead of O Ring and two identical metal rings which seal against each other on a lapped seal face.