In KNIVES CJRB Maileah October 4, 2024 Share Share on Facebook Share on Twitter Pinterest LinkedIn AR-RPM9 steel. It’s a tool steel in comparison to D2. Ceramic ball bearing, 59-61 on the hardness scale. by Budget-Potential-519 KnifeKnife PornKnives Write A CommentYou must be logged in to post a comment.