According to Terraria wiki entry for Sawmill crafting; it requires the following:
- 10 Wood
- 2 Iron Bars
- 1 Iron Chain
As shown in the screenshot below, I'm meeting all the requirements(rather I've more objects than required)
As can be seen; I have 32 wood, 15 Iron bars and 1 Iron chain(3rd row, 5th column). Still no option to craft a sawmill is displayed either on workbench or on Anvil!
Is this a bug?
EDIT
I should mention that it is a multi-player instance(in case, it has anything to do with the issue).
Best Answer
I notice you don't have cosmetic equipment slots, so I think you must be on an older version of the game.
Sawmills were added in 1.0.6.1, and social item slots were added in 1.0.4.