ASTM A182
Grade F1
Carbon-Moly Forged Flanges
Why Molybdenum Alone Is the First Step
Grade F1 is the base of the same alloy forging ladder that continues through Grade F12, F11, F5, F22, and F9 — but F1 is distinct from all of those in one specific way: it contains no chromium at all. Its single alloying addition is molybdenum, roughly 0.5%, added to plain carbon steel with no other alloy content.
Molybdenum alone genuinely improves creep strength — the same mechanism present across the entire chromium-molybdenum family — by stabilizing the steel’s microstructure against gradual softening and deformation at elevated temperature. What molybdenum alone does not provide is the oxidation resistance that chromium contributes; Grade F1 relies entirely on this single mechanism, with no chromium-based protective oxide layer benefit whatsoever.
That makes Grade F1 the correct, honestly limited answer specifically for the narrow band of service just above plain carbon steel’s temperature ceiling, where the concern is genuinely creep strength rather than oxidation or surface scaling. Once oxidation resistance becomes a real design factor — which happens at meaningfully lower temperatures than most people assume — the specification moves to Grade F12 or F11’s chromium-bearing chemistry rather than staying with F1.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our Grade F1 flanges and forged fittings are manufactured and verified by chemical composition and mechanical testing under our ISO 9001:2015 quality system.
A Note on Product Scope
ASTM A182 covers forged flanges, fittings, valves, and similar forged pressure-part components — it does not govern nuts or stud bolts, which fall under ASTM A194 and ASTM A193 respectively. If your requirement is for matching stud bolts to pair with F1 flanges, our carbon and alloy steel ASTM A193/A194 grades are the relevant fastener specifications — please let us know if you’d like both quoted together.
Where This Grade Genuinely Applies
Genuine Creep Strength Improvement
Molybdenum content resists gradual softening and deformation above plain carbon steel’s ceiling.
Cost-Effective Entry-Level Alloy
The most economical alloy step above plain carbon steel, without chromium’s added cost.
Correctly-Scoped, Honestly Limited
No oxidation resistance benefit — a narrow, specific fit for creep strength alone, not general elevated service.
Verified Mechanical Properties
Batch testing confirms genuine molybdenum content and mechanical properties.
Choosing Between Related Forged Alloy Grades
Grade F1 (This Page)
The entry-level alloy step, molybdenum alone, before chromium content is required.
You Are HereGrade F12
1% chromium added — the first step into genuine oxidation resistance above Grade F1.
View Grade F12 → Widely-Stocked, Moderate AlloyGrade F11
1.25% chromium — the widely available, moderate-temperature default higher on this same ladder.
View Grade F11 →Grade F1 vs Grade F12 — Quick Reference
Confirming whether oxidation resistance is genuinely a design factor before deciding F1’s chromium-free chemistry is sufficient. This table is the quick reference we use with buyers before quoting.
| Aspect | Grade F1 | Grade F12 |
|---|---|---|
| Chromium Content | None | ~1.00% |
| Molybdenum Content | ~0.50% | ~0.50%, identical |
| Oxidation Resistance | None beyond plain carbon steel | Modest, genuine improvement |
| Best Suited For | Creep strength alone, no oxidation concern | Moderate temperature with oxidation exposure |
Grade F1 Specification Details
Nominal Composition
- Chromium None
- Molybdenum 0.44 – 0.65%
- Carbon ≤0.20%
- UNS Designation K11522
Typical Mechanical Range
- Condition Normalized & Tempered / Annealed
- Service Temperature Just Above Carbon Steel Range
- Creep Strength Genuinely Improved
- Oxidation Resistance None Beyond Carbon Steel
Forged Components We Manufacture
- Flanges Weld Neck, Slip-On, Blind, Socket
- Forged Fittings Elbows, Tees, Reducers
- Valve Bodies Forged Components
- Custom Forgings On Request
Application Areas
Wherever service temperature genuinely exceeds plain carbon steel’s creep range, without meaningful oxidation exposure driving the material selection.
Entry-Level Elevated-Temperature Piping
carbon steel’s temperature range
General Industrial Process Piping
temperature process connections
Power Plant Feedwater Piping
feedwater system connections
General Elevated-Temperature Fittings
creep strength without oxidation
Standard Export Documentation
Prepared as standard practice for every Grade F1 flange or forged fitting shipment.
Mill Test Certificate (MTC)
Heat number, chemical composition, and mechanical property verification for every lot.
Chemical Composition Report
Confirms actual molybdenum content falls within the specified Grade F1 range.
Certificate of Conformance
Confirms the shipment matches the purchase order grade/size specification in full.
Certificate of Origin (COO)
Confirms India as country of manufacture for destination customs purposes.
NABL Accredited Test Reports
Independent mechanical, dimensional, and NDT testing available on request.
Commercial Invoice & Packing List
Itemized value, Incoterm, and detailed carton/weight breakdown for customs clearance.
Internationally Recognised Standards Coverage
Related Grades & Materials
ASTM A182 Grade F12
Our first chromium-bearing alternative, for service where oxidation resistance is genuinely needed.
View Grade F12 →ASTM A182 Grade F11
Our widely-available, moderate-temperature grade, higher on this same ladder.
View Grade F11 →ASTM A194 Grade 1 Nuts
Our general-purpose carbon steel nut grade, for matching fasteners at this entry-level service range.
View Grade 1 Nuts →Stainless Steel Fasteners Manufacturer India
Our broader fastener manufacturing capability across all major carbon, alloy, and stainless grades.
View SS Manufacturer Guide →Just Above Carbon Steel’s
Temperature Range?
Tell us your service temperature and whether oxidation exposure is a factor — we’ll confirm whether Grade F1 fits, or whether F12/F11’s chromium content is the better match. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Sales: +91 724 0000 733 · Support: +91 800 9315 333 · sales@akbarfasteners.in
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