IS 226 Mild Steel — Status, Replacement, and What Your Specs Should Say
IS 226 was once the workhorse Indian standard for structural mild steel. If you've inherited drawings or specifications from the 1990s or earlier, "IS 226 — Standard Quality" appears repeatedly. It was withdrawn long ago and replaced by IS 2062. This article explains the transition, what to write in your modern tender / drawing schedule, and how to handle legacy specifications that still cite the old code.
Bottom line: Use IS 2062:2011 (with latest amendment) for all new specifications. The closest equivalent to the old IS 226 Standard Quality is IS 2062 Grade E250 (formerly Fe 410W) with quality designator B (weldable) — typically written as "IS 2062 E250 BR" or "IS 2062 Grade B".
What Was IS 226?
IS 226:1975 (and earlier editions back to 1955) was the Indian Standard for Standard Quality Structural Steel. It defined yield strength, ultimate strength, elongation, and chemical composition for rolled sections, plates, and bars used in everyday construction. Mild steel buildings, transmission towers, factory sheds, and bridges through the 1980s and 1990s were almost universally specified to IS 226.
Key IS 226 properties:
| Parameter | IS 226 Standard Quality |
|---|---|
| Min yield strength (thickness ≤ 20 mm) | 250 N/mm² |
| Min ultimate strength | 410 N/mm² |
| Min % elongation (gauge length 5.65√A) | 23% |
| Designation | Fe 410-S (or "Standard Quality") |
Why Was IS 226 Withdrawn?
BIS consolidated several overlapping steel standards through the 1990s and 2000s — IS 226 (standard structural), IS 1977 (low-tensile), IS 8500 (medium and high tensile), IS 2062 (weldable structural) — into a single unified standard. The 2006 edition of IS 2062 brought everything into one document with grade designations (E165, E250, E275, E350, E410, E450, E550, E600, E650) and quality designators (A, BR, C, etc.). Subsequent revisions (2011, latest) further refined chemical composition and impact-toughness requirements.
The official withdrawal date for IS 226 is in BIS's catalogue archive — formally, IS 226 was superseded by IS 2062 in 1992-1999 through phased revisions. By the time IS 2062:2006 came out, IS 226 was no longer the active standard for new specifications.
The Mapping — IS 226 → IS 2062
The closest one-to-one mapping (same yield, similar ultimate, similar chemistry):
| Old (IS 226) | New (IS 2062:2011) | Notes |
|---|---|---|
| Fe 410-S (Standard Quality) | E250 Grade A | Direct chemistry equivalent. fy = 250, fu = 410. |
| Fe 410-S (with weldability stated) | E250 Grade BR | Weldable. Most building / bridge applications spec this today. |
| Fe 410-S for low-temperature service | E250 Grade C | Charpy V-notch tested. Used for cold regions, cryogenic equipment frames. |
Almost every "IS 226" specification you encounter on a legacy drawing should be re-written as "IS 2062 E250 Grade BR" for new procurement.
What to Write in a Modern Specification
Current best practice — tender BOQ + drawing schedule should read:
Material: Structural steel sections, plates, and bars shall conform to IS 2062:2011 Grade E250 with quality designator BR (weldable, room-temperature impact tested). Material test certificates (TC / mill certs) shall accompany every consignment, identifying heat number, batch composition, mechanical properties (yield, ultimate, elongation), and Charpy V-notch values where applicable. For heavy-duty applications, specify E350 (fy = 350 N/mm²) — see our IS 800 design guide for grade selection guidance.
The BR quality designator is the default for most structural work — it specifies weldability + room-temperature impact resistance. Use Grade B (without R) for unimpacted standard quality; Grade C for low-temperature impact (-20°C); CR for both impact and weather resistance.
Handling Legacy Specifications
You'll still encounter IS 226 in three scenarios:
- Existing structure inspection / retrofit. The original steel was IS 226 Fe 410-S. For capacity assessment, treat as IS 2062 E250 with the same fy = 250 N/mm² and fu = 410 N/mm². Use the partial safety factors of IS 800:2007 (LSM) — γm0 = 1.10 for yielding, γm1 = 1.25 for ultimate.
- Re-tendered old drawings. Update the material schedule before re-issuing — replace "IS 226" with "IS 2062 E250 BR" everywhere. Note the change in a revision drawing index. Don't leave IS 226 in active drawings; vendors may decline to quote.
- Old Indian / state PWD codes. Some legacy SoR (Schedule of Rates) item descriptions still mention IS 226 — particularly old PWD volumes. Modern SoR editions (DSR 2023, recent state PWD SSRs) have updated to IS 2062. See our State PWD SOR Editions Tracker.
IS 2062 Grade Map at a Glance
| Grade | fy (MPa) | fu (MPa) | Old IS equivalent | Typical Use |
|---|---|---|---|---|
| E165 | 165 | 290 | — | Limited use; low-stress applications |
| E250 | 250 | 410 | IS 226 Standard Quality (Fe 410-S) | General buildings, most beams + columns, trusses |
| E275 | 275 | 430 | — | Bridges, some industrial |
| E350 | 350 | 490 | IS 8500 Fe 490 | Bridges, heavy industrial, crane structures |
| E410 | 410 | 540 | IS 8500 Fe 540 | Heavy-duty crane structures, tall buildings |
| E450 | 450 | 570 | IS 8500 Fe 570 | Bridges, towers, specialised structures |
| E550 | 550 | 650 | IS 8500 Fe 650 | High-strength applications |
| E600 / E650 | 600 / 650 | 730 / 780 | IS 8500 Fe 730/780 | Specialised; not stocked off-shelf in India |
International Equivalents
| IS 2062 Grade | ASTM (USA) | EN 10025 (Europe) |
|---|---|---|
| E250 BR | A36 (fy = 250, fu = 400-550) | S235JR (fy = 235, fu = 360) |
| E275 | A529 Gr 50 | S275JR |
| E350 | A572 Gr 50 (fy = 345) | S355JR |
| E450 | A572 Gr 65 | S420 / S450 |
For deeper comparison (composition, weldability nuances, test methods), see our IS 2062 vs ASTM A36 article.
Related InfraLens Resources
- IS 2062:2011 — Hot Rolled Medium and High Tensile Structural Steel
- IS 800:2007 — Steel Design Code
- IS 808:1989 — Steel Section Dimensions
- IS 800 Steel Design Beginner's Walkthrough
- IS 2062 vs ASTM A36 Comparison
- Steel Section Types — ISMB / ISHB / ISMC / ISA
- ISMB Weight Chart
- Steel Section Table · Plate Weight Calculator
- Steel QA/QC family — material acceptance protocols
- State PWD SOR Editions Tracker
FAQ
Is IS 226 still valid for procurement?
No. IS 226 has been formally superseded. Modern procurement, BIS certification, and CPWD / state PWD work all reference IS 2062. Any "IS 226" callout on a current tender should be flagged as a clerical legacy and replaced with the IS 2062 grade equivalent.
What if my existing structure was built to IS 226?
For assessment, capacity analysis, and retrofit design — treat IS 226 Fe 410-S material as IS 2062 E250 BR. Same yield strength, same ultimate. Apply IS 800:2007 LSM safety factors. The original material's chemistry and inclusions may have ageing effects but, in practice, this is rarely a binding concern for 30-50 year-old mild steel.
Why does the IS 226 spec still appear in some PWD SoR items?
Slow update cycles. Some State PWD SoR volumes are reprinted only every 3-5 years; many continue to reference legacy codes verbatim. The DSR 2023 (CPWD) and recent state SSRs have largely cleaned this up. Always cross-check the material spec in your contract against the current BIS catalogue.
How do I write "IS 226 equivalent" on a drawing if procurement still insists?
The correct callout: "Structural steel: IS 2062:2011 Grade E250 Quality BR (equivalent to legacy IS 226 Standard Quality)". This satisfies modern BIS specification and gives the legacy reader the cross-reference they expect.
Is Fe 410W the same as Fe 410-S?
Close, not identical. "Fe 410W" was the welding-grade variant under IS 226 (with controlled C, Mn, P, S for weldability). "Fe 410-S" was the basic Standard Quality (looser composition). In IS 2062 terminology: Fe 410W ≈ E250 Grade BR; Fe 410-S ≈ E250 Grade A. For all welded structures (i.e. almost everything), spec the weldable grade.
Summary
IS 226 is a legacy code — never use it for new procurement. The current standard is IS 2062:2011, and the direct replacement for IS 226 Standard Quality is E250 Grade BR. When auditing old drawings or assessing existing structures, treat IS 226 material as IS 2062 E250 for capacity calculations under the current IS 800:2007 framework. Update specifications, train procurement teams, and the legacy designation eventually disappears from active drawings.