I didn't bother to look or to measure but I did a bit of research and found that a mature copperhead (which this wasn't) have fangs about .3" (7.2mm) in length. That's not very long and would not even likely to get through a good thick pair of cordura uppers. Also I found out that a copperhead strikes and lets go immediately one large animals. And males are aggressive during late summer and fall which is their mating season. So I had an adrenaline pumping experience and learned a few things about copperheads.