These hexagonal head flange nuts are grade 8 steel. The wide serrated flange acts as an integrated non-spinning washer. The main benefits of this design is that:

the pressure of the nut is distributed over the part being secured
there is a lower likelihood of the nut loosening over time from vibration
a tighter fit can be achieved compared to a normal washer and nut fitting

The BZP (Bright Zinc Plated) coating provides corrosion resistance. Available in a range of quantities to suit domestic DIY, one off-projects and commercial use.

Technical Specifications: