I think it would have made more sence if the nails were shorter and driven all the way in. The long ones present a lot of blunt sides nails on the ends all around. Unless the flat parts were cut off and ground down to a point, I wouldn't see this as being fully effective.
i always figured a good machette strapped to a baseball bat would be better. anything modified to cause harm is an offensive weapon. only know because i wanted to do this exact thing. gravity and butterfly knives are illegal here and throwing stars. least i have my ukara to buy realistic bb guns. anyway the bat does look good
...Anyway, that thing looks cool but I would have chosen a longer bat for a better "reach". Not to mention that I don't want to be in the "splash zone".
That's the problem with close-range weapons where zombies are concerned. Assuming whatever caused the "zombification" in the first place is hazardous to living humans, a person could easily be infected by flying spatter, i.e. blood or other tissue. To be sure, you'd need a nearly-indestructable Hazmat suit or something comparable to ensure your own safety while wielding a baseball bat with nails, a machete, a crowbar, a 2X4, or whatever.