Here are common uses for each of the steel rebar sizes:

• #3 — This thin and cost-effective mild steel rebar material adds strength to concrete roads, driveways, or patios. It’s also common in poured concrete swimming pools to provide the pool walls with shape and strength.
• #4 — Slightly thicker, #4 rebar is perfect for adding strength to highways and can give columns and slabs added strength.
• #5 — This type of rebar is commonly used for bridges and highways.
• #6 — Commonly found in foundations, retaining walls, and roads or highways.
• #7 — This rebar size can provide support for structures like multi-story parking garages and bridges.
• #8 — #8 rebar is perfect for medium to heavy commercial applications. It can be used for slabs, sea walls, columns, and beams.
• #9 — This thick and durable material is the go-to rebar for high-rise construction projects, sea walls, and retaining walls.
• #10 — Perfect for medium to heavy commercial-use projects, this size provides structural support in beams, columns, and more.
• #11 — This heavy-duty rebar is thick and strong, so it is often used for load-bearing structures.
• #14 — One of the heaviest and thickest rebars available in standard sizes, the #14 rebar size is well suited for bridges, parking structures, tall buildings, and docks.
• #18 — This large, strong rebar size is used for large buildings, industrial facilities, and other large-scale buildings.