When sourcing medium carbon steel for high-stress components like shafts, gears, or hydraulic fittings, one material dominates global industrial drawings: 45# steel.
As a leading precision manufacturing factory, we understand that selecting the right material grade is only the first step. Whether your project specifies C45 (1.0503) in Europe or AISI 1045 in the USA, knowing how this medium carbon steel behaves during CNC machining and heat treatment is critical for quality assurance.
1. International Standard Equivalents of 45# Steel
For procurement managers and engineers, cross-referencing global standards is vital to avoid material substitution errors.
| Country / Region | Standard | Grade | Material No. |
| China | GB/T 699 | 45# | — |
| Germany/EU | DIN EN 10083 | C45 | 1.0503 |
| USA | ASTM A29 / SAE | 1045 | — |
| Japan | JIS G4051 | S45C | — |
| Russia | GOST | 45 | — |
2. Chemical Composition: Why 0.45% Carbon Matters
The “45” in 45# steel represents its average carbon content of 0.45%. This specific chemistry allows the steel to achieve a perfect balance of ductility and high strength after heat treatment.
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Carbon (C): 0.42% – 0.50%
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Silicon (Si): 0.17% – 0.37%
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Manganese (Mn): 0.50% – 0.80%
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Phosphorus (P) / Sulfur (S): ≤ 0.035% (Low impurities for better weldability)
3. Mechanical Properties for 45# parts (Typical pipe fitting Factory Values)
In our manufacturing facility, we test 45# steel in two primary states: Normalized (for easy machining) and Quenched & Tempered (Q+T) (for high-load durability).
| Property | Normalized (Typical) | Quenched & Tempered (Max) |
| Tensile Strength | ≥ 600 MPa | 800 – 1050 MPa |
| Yield Strength | ≥ 355 MPa | ≥ 550 MPa |
| Elongation | ≥ 16% | ≥ 12% |
| Hardness | 170 – 210 HB | 20 – 55 HRC (Adjustable) |
4. Heat Treatment Expertise for 45# pipe fittings : Unlocking Performance
At our ISO-certified factory, we utilize advanced heat treatment to customize the mechanical limits of 1045/C45 steel:
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Normalizing (840–870°C): Refines grain structure. This is the standard state we recommend for CNC machining to ensure dimensional stability.
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Quenching (820–860°C): Rapid cooling in water or oil to maximize hardness.
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Tempering (200–600°C): Adjusts the final hardness. For example, hydraulic piston rods are often tempered to a specific toughness to prevent snapping under pressure.
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Induction Hardening: Ideal for shafts. We can harden only the “skin” of the part to HRC 50+ while keeping the core tough and flexible.
Factory Note: 45# steel has low hardenability. For parts thicker than 60mm, the core hardness may be lower than the surface. For deep-core hardness in large parts, ask our engineers about alloy alternatives like 42CrMo.
5. Why Partner with a 45# Steel Manufacturing Expert?
While 45# steel is widely available, the consistency of the final product depends on the factory’s process control.
Precision CNC Machining for 45# pipe fittings
45# steel has excellent machinability (approx. 65% of 1212 carbon steel). In our CNC machining center, we optimize tool paths and cooling to prevent the “work hardening” often seen in cheaper grades. This ensures smooth threads and high-precision tolerances (+/- 0.01mm).
Surface Treatment Options for 45# pipe fittings
Because 1045 steel is prone to rust, we offer a variety of in-house finishes:
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Zinc Plating / Galvanizing (Salt Spray Test 48h – 96h)
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Black Oxide (For industrial aesthetics and mild protection)
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Hard Chrome Plating (Essential for hydraulic cylinder rods)
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Electroless Nickel (Superior corrosion resistance for fluid power fittings)
6. Typical Industrial Applications for 45# pipe fittings
As a specialized component manufacturer, we supply 45#/C45 parts for:
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Hydraulics: High-pressure hose fittings, ferrules, and manifold connectors.
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Automotive: Axles, steering knuckles, and crankshafts.
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Agriculture: Drive shafts, gears, and heavy-duty pins for tractors.
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General Engineering: Precision bolts, studs, and custom mechanical couplings.
7. FAQ – Sourcing 45# / C45 / 1045 Steel
Q: Is 45# steel weldable?
A: Yes, but with caution. Due to the medium carbon content, we recommend preheating the part to 150-250°C and using post-weld stress relief to prevent cracking.
Q: Can I use 45# steel instead of Q235 (Mild Steel)?
A: If your part requires higher wear resistance or needs to be hardened, 45# is the better choice. If you only need simple structural welding, Q235 is more cost-effective.
Q: What is the MOQ for custom 45# steel parts?
A: As a profesional china zhejiang pipe fitting factory, our moq is 2000pcs for custom made cnc turning parts.
Q: what your company main supply ?
We can supply different types of pipe fittings ,such as union , elbow fitting , tee , hex nipples and bolts , steel plug etc . we have more than 80sets of cnc lathe machines, could supply punching , welding , laser , drill , thread service for different types of pipe fittings.
Conclusion: Reliable 45# Steel Solutions
Choosing 45# (C45/1045) steel offers a cost-effective route to high-performance mechanical parts. By partnering with a cnc turning factory that understands the nuances of heat treatment and CNC precision, you ensure that your components will perform under the toughest conditions.
Need a quote for custom 45# steel components?
[Contact Our Engineering Team Today] – We provide full Material Test Reports (MTR) and competitive factory-direct pricing for all global orders.
