Magnus Archery Black Hornet Ser-Razor 4 Blade Broadhead - 3 PackBlade thickness for the Black Hornet Ser Razor main blade is . 059 thousands of a inch, the bleeder blade is . 040 thousands of a inch. All Magnus Black Hornets perform flawlessly from the fastest bows on the planet with field tip accuracy. The quality of our construction is unmatched, but if you break one, we will replace it according to our Lifetime Guarantee. You can sharpen the main blades yourself, or replace them either way, the Black Hornet