A wellhead seal assembly that forms a metal-to-metal seal between inner and outer wellhead members. A metal seal ring has inner and outer legs that are threaded to each other and separated by a slot and provide bi-directional sealing. The threaded connection provides a pathway for annular pressure into the slot. The inner and outer legs have inner and outer walls, respectively. Inner and outer legs have a soft metal inlay on their interior surfaces. Wickers may be located on the outer surface of the inner wellhead member and on the inner surface of the outer wellhead member. An energizing ring is moved into the slot to force the outer and inner walls of the seal into sealing engagement with the inner and outer wellhead members. The soft metal inlays deform onto the energizing ring. If present, wickers on the wellhead members embed into the walls of the seal ring.