Stone Bridge石の橋

Used to cross chasms and water but also makes for a nice floor.
In-game description

What is Stone Bridge? Features and uses

Stone Bridge is a common item in Core Keeper (Placeables & furniture). It is crafted at the Iron Workbench from Stone Block ×1.

Stone Bridge notes

Placed over liquids or pits, it forms a walkable path.
It also serves as base flooring that you can build on.

These notes cover behavior that the game files do not show directly. They are based on facts from the Core Keeper Wiki (Fandom) page "Stone Bridge" (CC BY-SA 3.0), rewritten in this site's own words.

How to craft Stone Bridge (materials)

Crafted at Iron Workbench What each crafting station makes →

Material	Amount	How to get the material
Stone Block	× 1

What you get from salvaging Stone Bridge (Salvage and Repair Station)

Stone Bridge can be salvaged. Salvaging it gives the following items.

For each material, the amount is "amount used to craft × 0.49 (lower when durability is down, 0.3 at 0 durability) × the item's multiplier", and a fraction is the chance of one more (2.4 means 2, with a 40% chance of 3). The range is from 0 durability to full durability (items without durability always count as full). Scrap parts are a fixed number set by the item level. All items that can be salvaged are listed in salvaging.