If you want to get technical about bokkens you can read this
If you want a more mystical approach you can read this
I'm willing to bet that your weapons are Japanese white oak. Pine is too soft to use.
These guys also seem reasonable. At least you're not paying $100+USD for a piece of wood.
Yeah. These guys (By the Sword) make wasters or training weapons. I don't think them use them in actual SCA events.
Edward Dix who wrote one of the above articles, also mentioned denting. Both articles mentioned selecting the best wood possible. I have yet to use the hickory bokken in contact. I've managed to dent up a Japanese white oak bokken. Of course the cheaper bokken against it, shattered clean through.
Let me take a closer look and I'll get back with you on an answer.