# Yield Strength of Fe 500 TMT Steel

> Yield strength is the stress at which structural steel starts to deform permanently. This page explains the Fe 500 grade with an earthquake example.

Canonical: https://superwise.site/glossary/yield-strength/
Last updated: 2026-11-01

The stress at which a steel bar stops springing back and starts to bend or stretch permanently, measured in MPa.

## What is Yield Strength (Steel Rebar)?

Yield strength is the mechanical property of structural steel [reinforcement](https://superwise.site/glossary/reinforcement-rebar/) ([TMT bars](https://superwise.site/glossary/tmt-bars/)) that sets the load a bar can carry while staying elastic, measured in megapascals (MPa). Below it, the bar springs back to its straight shape when the load is removed. Above it, the steel yields, which means it deforms and stretches permanently, though it does not snap at once.

## Practical example

In the Indian grade Fe 500, the 500 is the yield strength in MPa. If an earthquake puts 400 MPa on a column, the Fe 500 steel bends elastically and returns to shape when the shaking stops. If a severe quake puts 550 MPa on it, the steel yields and stays bent. Because the steel is ductile, it bends instead of shattering, which keeps the building from a sudden pancake collapse.

## In SuperWise

In SuperWise a steel delivery is recorded on a [material delivery challan](https://superwise.site/glossary/material-delivery-challan/) (MDC) against a purchase order line, with photos and a [QC](https://superwise.site/glossary/quality-assurance-quality-control/) status of Satisfactory, Rejected or Unsatisfactory but Accepted. A steel resource can carry a quality checklist for the delivery, where a number field can hold the yield figure from the mill test certificate and a photo field the certificate itself. A challan must be approved before it can be billed.

[Quality and safety checklists](https://superwise.site/features/construction-quality-safety/)

## Related terms

- [TMT Bars (Thermo Mechanically Treated)](https://superwise.site/glossary/tmt-bars/)
- [Reinforcement (Rebar)](https://superwise.site/glossary/reinforcement-rebar/)
- [Quality Assurance / Quality Control (QA/QC)](https://superwise.site/glossary/quality-assurance-quality-control/)

## Related
- [TMT Bars (Thermo Mechanically Treated)](https://superwise.site/glossary/tmt-bars/)
- [Reinforcement (Rebar)](https://superwise.site/glossary/reinforcement-rebar/)
- [Quality Assurance / Quality Control (QA/QC)](https://superwise.site/glossary/quality-assurance-quality-control/)
- [Quality and safety checklists](https://superwise.site/features/construction-quality-safety/)