The posts on this page are fired to cone 13 during manufacturing. The suggested manufacturer's cone rating is conservatively estimated based upon expected (heavy) loads. You'll find the posts will continue to perform well at higher cone under less heavy (and more even loading).
NOTE: Kiln posts are fragile. We make every effort to pack them well, but sometimes one will break in shipping. If this happens we will credit you the cost of the post, and we will not ship you a replacement. Since you are likely to break posts as you use them, we recommend that you purchase spares. Small chips which are cosmetic only and do not affect the functionality will not be credited.