Partick, with bone it’s not a much of a ‘grain’ thing. Bones don’t really have a ‘grain’ in the sense we think of wood as having a grain. Though there is a directional cellular orientation for some of the bone-matrix in some bones, such as the long bones of the legs, most bone lacks any pronounced directional orientation.

Bone cells interlock to a degree not seen in wood. When we speak of splitting bone we are speaking of spreading the bone apart to such a degree that we directionally stress the interlocking cell martix to the extent that a linear fracture is created. That’s why it’s rare to ever see a split that runs the length of a bone, like the full-length splits you get in wood when splitting kindling or firewood. With bone it’s more likely that a chip or chunk of bone will be broken away.

The bone’s interlocking structure but somewhat brittle nature is also why a rotating single-bevel BH generally makes a ‘hole’ when it penetrates the scapular flat, rather than creating a split; and why double-bevel BH’s punch such neat ‘profile’ holes in the scapular flat. To get a split through the scapular flat generally requires that the BH’s impact be down in the heavier portion of the scapula, near the head, and that the split initated there be in a direction that takes it through the area of the flat.

Broadhead orientation to the ‘long or short’ dimention of the bone has shown no difference in the bone-splitting tendency for any of the broadheads tested. The orientation of the broadhead to the long or short dimention of the bone does, however, make a difference in the direction of any split generated. Unlike wood, bone can be split in any direction. As far as splitting bones, what becomes important in the BH’s design is its ability to creat a directional spreading force sufficient to over-stress the bone matrix, creating a fracture. No BH design does that as well as the single-bevel single blade.

Hope that answered clearly enough to be understandable.

Ed