M10 x 1.5 Serrated Flange Lock Nut DIN6923-10 Plated M10-1.50 serrated flange nut cl 8 din 6923 plated MSFN10 $0.150/ea
M12 x 1.25 Serrated Flange Lock Nut - Plated M12 x 1.25 serrated flange lock nut - plated MSFN121.25 $0.390/ea