# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/DWjYPizgOpC
- **Gondola URL:** https://gondola.cc/posts/62451537-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/36d18e89f2.jpg
- **Posted:** 2026-03-31T14:52:13.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

Most rebar starts as recycled steel scrap. This scrap is melted in an electric arc furnace (EAF), where high-current arcs between graphite electrodes generate temperatures above 1,600°C. Oxygen is injected to remove impurities such as carbon, silicon, and phosphorus, while slag-forming agents bind unwanted elements so they can be separated.

The molten steel is then refined to achieve a target composition. Small adjustments in carbon, manganese, and microalloying elements like vanadium or niobium influence yield strength, ductility, and weldability. Once chemistry is verified, the steel is continuously cast into billets—semi-finished rectangular sections that solidify under controlled cooling.

Billets are reheated to roughly 1,100–1,250°C and fed into a rolling mill. Here, they pass through a sequence of rollers that progressively reduce cross-section and elongate the material into long bars. The final rolling stands imprint the characteristic ribbed pattern, which increases mechanical bonding with concrete.

To achieve the required mechanical properties, most modern rebar undergoes thermomechanical treatment (TMT). Immediately after hot rolling, the bar is rapidly quenched with water, forming a hardened martensitic outer layer. Heat from the still-hot core then tempers this layer, producing a strong exterior with a more ductile interior. This gradient structure is critical: it allows rebar to absorb stress without brittle failure.

After cooling, the bars are cut to length, bundled, and labeled with grade markings that indicate strength class and manufacturer. Quality control includes tensile testing, bend tests, and dimensional checks to ensure compliance with standards such as ASTM A615 or EN 10080.

At scale, this entire process runs continuously, with tight feedback loops controlling temperature, composition, and rolling speed. The result is a high-volume product engineered to perform reliably inside the concrete structures we depend on every day.

If you want more deep dives into how everyday engineering materials are made, follow and share. What process should we break down next?

#STEM #Engineering #MaterialsScience #Manufacturing #CivilEngineering

## Stats

- **Views:** 13,935
- **Likes:** 274
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- **Comments:** 2

## Tags

engineering, stem, materialsscience, manufacturing, civilengineering

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