Martial Arts

I'm curious is metal harder and more damaging then wood. I used tonfa made of wood then I got my hands on one of them old school pr 24 tonfa 24 inch instead of traditional 18. I believe it's better to have one long instead of two now but I thought the polypropylene might not be good for self defense because it's plastic and lighter mabye softer. Now i see they have 3 pound 24 inch tonfa which is twice the weight of pr24 made of aluminum. Im thinking of buying one for self defense but I honestly don't know what is better buying a custom one made of high dollar and density wood like ebony might be better though