Metric Fine threaded ( M20 x 1.5mm ) High Tensile Grade 10 Flange Nuts with great corrosion resistence due to the high performing Geomet 500 Zinc Flake Coating. 
DIN 6923
Spanner Size 30mm
These are the preferred coatings for fasteners and other parts in the automotive industry, as they offer various advantages:
Good appearance (colouring)
Very good protection against corrosion (500-1000 hours with a required duration of salt spray in the case of our products)
Resistant to extreme temperatures
Excellent chemical resistance
Environmentally friendly
Excellent friction characteristics
No warm-loosening torque
No risk for high-strength fasteners of any hydrogen embrittlement
Electric conductivity