ASTM A105 vs Other Materials – Complete Engineering Comparison Guide
📌 Introduction
ASTM A105 is a widely used carbon steel forging specification for piping components such as flanges, fittings, and valves, particularly in pressure systems. However, it is often compared to other materials like A106, A234, A350 LF2, and even AISI 1018. This guide provides a detailed comparison to help engineers, procurement teams, and manufacturers choose the right material for the application.
1️⃣ ASTM A105 vs ASTM A106
| Feature | ASTM A105 | ASTM A106 |
|---|---|---|
| Product Form | Forged components (flanges, etc.) | Seamless carbon steel pipes |
| Specification Type | Forged carbon steel | Seamless pipe for high temp |
| Use Case | Flanges, valves, fittings | Pressure piping, boilers |
| Heat Treatment | Optional (N = normalized) | Required for Grades B & C |
| Working Temp Range | Up to ~500°C | Up to ~540°C (Grade C) |
🔎 Summary: A105 is for forged components, while A106 is for seamless pipes - they complement, not compete.
2️⃣ ASTM A105N vs ASTM A105
| Feature | ASTM A105 | ASTM A105N |
|---|---|---|
| Heat Treatment | No specific requirement | Normalized (heat treated) |
| Toughness | Standard | Improved |
| Grain Structure | May vary | Uniform, refined |
| Applications | General | Severe or low-temperature service |
🔎 Summary: A105N is A105 with normalization - better grain refinement, improved toughness.
3️⃣ ASTM A105 vs ASTM A181
| Feature | ASTM A105 | ASTM A181 |
|---|---|---|
| Application Pressure | Medium to high | Low pressure |
| Common Use | Flanges, valves, fittings | Flanges for low-pressure systems |
| Mechanical Strength | Higher | Lower |
| Working Temp Range | Up to ~500°C | Less demanding environments |
🔎 Summary: A181 is a lower-grade forged carbon steel for low-pressure systems. A105 is more versatile.
4️⃣ ASTM A105 vs ASTM A234
| Feature | ASTM A105 | ASTM A234 |
|---|---|---|
| Manufacturing | Forged | Wrought |
| Application | Flanges, fittings | Butt-weld pipe fittings |
| Material Type | Forged carbon steel | WPB (wrought carbon steel) |
🔎 Summary: A105 is used for forged fittings, A234 (especially WPB grade) is used for butt-weld fittings.
5️⃣ ASTM A105 vs ASTM A216 WCB
| Feature | ASTM A105 | ASTM A216 WCB |
|---|---|---|
| Manufacturing | Forged | Cast |
| Common Forms | Flanges, fittings, valves | Valve bodies, flanges |
| Surface Integrity | Better due to forging | May have casting defects |
| Mechanical Properties | Stronger, denser | Slightly lower |
🔎 Summary: A216 WCB is cast carbon steel; A105 is forged - better for critical sealing and strength.
6️⃣ ASTM A350 LF2 vs ASTM A105
| Feature | ASTM A105 | ASTM A350 LF2 |
|---|---|---|
| Temp Range | -29°C and above | -46°C and above |
| Low-Temp Toughness | Moderate | Excellent |
| Heat Treatment | Optional | Required (normalized and tempered) |
| Use Case | General flanges | Cryogenic and low-temp flanges |
🔎 Summary: A350 LF2 is the go-to choice for low-temperature service; A105 is general-purpose.
7️⃣ AISI 1018 vs ASTM A105
| Feature | ASTM A105 | AISI 1018 |
|---|---|---|
| Carbon Content | ~0.35% | ~0.18% |
| Strength | Higher | Lower |
| Use | Pressure components | Machined parts, mild structures |
| Machinability | Good | Excellent |
🔎 Summary: AISI 1018 is mild steel for machining; A105 is a stronger forging grade.
8️⃣ ASME SA105 vs ASTM A105
| Feature | ASTM A105 | ASME SA105 |
|---|---|---|
| Usage Standard | ASTM (general) | ASME Boiler & Pressure Vessel Code |
| Material | Identical | Identical |
| Certification | Optional | Must meet ASME Section II |
🔎 Summary: Chemically the same; SA105 is certified for ASME pressure vessels and boilers.
✅ Conclusion & Selection Guide
| Application | Recommended Material |
|---|---|
| General forged flanges | ASTM A105 |
| High-temp pipe systems | ASTM A106 |
| Low-temp forged flanges | ASTM A350 LF2 |
| Butt-weld pipe fittings | ASTM A234 WPB |
| Cast valves/flanges | ASTM A216 WCB |
| Low-pressure flanges | ASTM A181 |
| General machining steel | AISI 1018 |
| ASME code vessel systems | ASME SA105 |
💬 FAQs
Q1: Can ASTM A105 be used in low-temperature service?
A: Not unless it is normalized or certified to meet A350 LF2 requirements.
Q2: Is ASTM A105 the same as SA105?
A: Chemically and mechanically yes, but SA105 meets ASME certification.
Q3: What's the difference between forging (A105) and casting (A216)?
A: Forging produces stronger, denser parts with fewer internal defects than casting.
