Mill Supply carries a variety of replacement Lawn Mower Wheels including Steel Wheels (Diamond Tread) and many other mower parts.

6" X 1-1/2" Steel wheel, 1-3/8" offset hub, ball bearing with 1/2" bore, white

7" x 1-1/2" Steel wheel, 1-3/8" offset hub, ball bearing with 1/2" bore, white

7-1/2" x 1-1/2" Steel wheel, 1-3/8" offset hub, ball bearing with 1/2" bore, white

8" x 1-3/4" Steel wheel, 1-3/8" offset hub, ball bearing with 1/2" bore, white
Mower-parts.net carries replacement Steel Wheels (Diamond Tread) as well as other mower parts & accessories.