Alloy Steel - Grades and Specifications
Overview of Alloy Steel
Alloy steel is a high-performance engineering steel produced by adding controlled amounts of alloying elements such as chromium, nickel, molybdenum, manganese, and silicon to carbon steel. These additions significantly improve strength, toughness, fatigue resistance, hardenability, wear resistance, and impact performance.
Alloy steel is widely used throughout aerospace, defence, oil and gas, rail, mining, automotive, power generation, construction equipment, marine, and heavy engineering industries where components are subjected to high loads, cyclic stresses, impact forces, and demanding operating environments.
Chargentum supplies alloy steel round bars in hardened and tempered conditions, providing excellent machinability, toughness, and mechanical performance for precision engineering applications throughout the UK.
Alloy Steel Types
| Type | Alternative Designation | Alloy Type | Typical Applications |
|---|---|---|---|
| EN16T Round Bar | 605M36T | Manganese-Molybdenum Alloy Steel | Shafts, Axles, Studs, Fasteners |
| EN19T Round Bar | 709M40T | Chromium-Molybdenum Alloy Steel | Hydraulic Rods, Gears, Drive Shafts |
| EN24T Round Bar | 817M40T | Nickel-Chromium-Molybdenum Alloy Steel | Aerospace Components, Transmission Systems |
Notes:
- All grades are supplied in hardened and tempered condition (T Condition)
- Excellent fatigue resistance
- Good machinability
- Suitable for induction hardening
- Available with full mill certification
Standard Grades
Chargentum supplies the UK’s most commonly specified alloy steel grades suitable for demanding engineering applications.
| Grade | Alternative Designation | Tensile Strength (MPa) | Yield Strength (MPa) | Typical Applications |
|---|---|---|---|---|
| EN16T | 605M36T | 850–1000 | 680 | General Engineering |
| EN19T | 709M40T | 850–1000 | 680 | Hydraulic and Mechanical Equipment |
| EN24T | 817M40T | 850–1100 | 680–850 | Aerospace and High-Performance Engineering |
Chemical Composition (Typical % by Mass)
| Element | EN16T | EN19T | EN24T | Function |
|---|---|---|---|---|
| Carbon (C) | 0.32–0.40 | 0.36–0.44 | 0.36–0.44 | Strength and hardness |
| Silicon (Si) | 0.10–0.35 | 0.10–0.35 | 0.10–0.35 | Deoxidation |
| Manganese (Mn) | 1.30–1.70 | 0.45–0.70 | 0.45–0.70 | Toughness |
| Chromium (Cr) | Residual | 0.90–1.40 | 0.90–1.40 | Wear resistance |
| Nickel (Ni) | Residual | Residual | 1.30–1.80 | Toughness |
| Molybdenum (Mo) | Residual | 0.20–0.35 | 0.20–0.35 | Hardenability |
| Sulphur (S) | ≤0.05 | ≤0.05 | ≤0.05 | Controlled residual |
| Phosphorus (P) | ≤0.05 | ≤0.05 | ≤0.05 | Controlled residual |
Mechanical Properties
| Property | EN16T | EN19T | EN24T | Notes |
|---|---|---|---|---|
| Yield Strength | 680 MPa | 680 MPa | 680–850 MPa | Permanent deformation point |
| Tensile Strength | 850–1000 MPa | 850–1000 MPa | 850–1100 MPa | Maximum load before failure |
| Elongation | 13–16% | 13–16% | 13–16% | Ductility before fracture |
| Reduction of Area | 45% | 45% | 45% | Plastic deformation |
| Hardness | 248–302 HB | 248–302 HB | 248–302 HB | Hardened and tempered |
| Modulus of Elasticity | 210,000 MPa | 210,000 MPa | 210,000 MPa | Material stiffness |
| Density | 7,850 kg/m³ | 7,850 kg/m³ | 7,850 kg/m³ | Mass per cubic metre |
Delivery Conditions
| Condition | Description |
|---|---|
| Hardened & Tempered (T) | Standard supply condition |
| Hot Rolled | Standard mill finish |
| Peeled | Improved dimensional accuracy |
| Turned | Machined finish |
| Ground | Precision finish |
| Precision Ground | Tight tolerance applications |
| Ultrasonically Tested | Available on request |
Physical Properties
| Property | Value | Notes |
|---|---|---|
| Density | 7,850 kg/m³ | Typical alloy steel |
| Modulus of Elasticity | 210,000 MPa | Material stiffness |
| Thermal Expansion | 11.5 ×10⁻⁶ /°C | Linear expansion |
| Thermal Conductivity | 42–46 W/mK | Heat transfer |
| Electrical Conductivity | 8–10 % IACS | Electrical performance |
| Melting Range | 1420–1460°C | Approximate range |
Standards & Specifications
| Grade | BS Designation | EN Equivalent | AISI / SAE Equivalent | DIN Equivalent |
|---|---|---|---|---|
| EN16T | 605M36T | 36MnVS4 | Similar Engineering Grade | 1.1178 |
| EN19T | 709M40T | 42CrMo4 | 4140 | 1.7225 |
| EN24T | 817M40T | 34CrNiMo6 | 4340 | 1.6582 |
Heat Treatment Information
| Process | EN16T | EN19T | EN24T | Purpose |
|---|---|---|---|---|
| Annealing | 650–700°C | 650–700°C | 650–700°C | Improve machinability |
| Normalising | 850–880°C | 850–880°C | 850–880°C | Grain refinement |
| Hardening | 820–850°C | 830–860°C | 830–860°C | Increase strength |
| Tempering | 550–680°C | 550–680°C | 550–680°C | Improve toughness |
| Stress Relieving | 550–650°C | 550–650°C | 550–650°C | Reduce residual stress |
METAL TYPES & APPLICATIONS
EN16T (605M36T) Alloy Steel Round Bar
EN16T (605M36T) is a manganese-molybdenum alloy steel supplied in the hardened and tempered condition. It offers an excellent combination of tensile strength, toughness, fatigue resistance, and machinability, making it suitable for a wide range of engineering applications. EN16T is commonly used for shafts, axles, studs, bolts, couplings, gears, and general engineering components where moderate to high strength is required without the additional alloy content found in EN19T and EN24T.
The grade responds well to machining and heat treatment processes and is widely specified across the automotive, rail, agricultural, construction equipment, and manufacturing sectors. Chargentum supplies EN16T round bars in a comprehensive range of diameters, delivered throughout the UK.
| Diameter (mm) | Weight (kg/m) | Length (mm) | Condition | Grade | Typical Application |
|---|---|---|---|---|---|
| 20 | 2.47 | 3000-6000 | T | EN16T | Studding |
| 25 | 3.85 | 3000-6000 | T | EN16T | Fasteners |
| 30 | 5.55 | 3000-6000 | T | EN16T | Shafts |
| 35 | 7.55 | 3000-6000 | T | EN16T | Pins |
| 40 | 9.87 | 3000-6000 | T | EN16T | Axles |
| 45 | 12.49 | 3000-6000 | T | EN16T | Couplings |
| 50 | 15.42 | 3000-6000 | T | EN16T | Machine Parts |
| 55 | 18.66 | 3000-6000 | T | EN16T | Drive Components |
| 60 | 22.20 | 3000-6000 | T | EN16T | Gear Blanks |
| 65 | 26.05 | 3000-6000 | T | EN16T | Shafts |
| 70 | 30.21 | 3000-6000 | T | EN16T | Engineering Components |
| 75 | 34.69 | 3000-6000 | T | EN16T | Heavy Engineering |
| 80 | 39.46 | 3000-6000 | T | EN16T | Industrial Equipment |
| 85 | 44.55 | 3000-6000 | T | EN16T | Mechanical Components |
| 90 | 49.94 | 3000-6000 | T | EN16T | Large Components |
| 95 | 55.64 | 3000-6000 | T | EN16T | Power Transmission |
| 100 | 61.65 | 3000-6000 | T | EN16T | Large Shafts |
| 110 | 74.59 | 3000-6000 | T | EN16T | Structural Machinery |
| 125 | 96.33 | 3000-6000 | T | EN16T | Heavy Components |
| 140 | 120.87 | 3000-6000 | T | EN16T | Industrial Machinery |
| 150 | 138.72 | 3000-6000 | T | EN16T | Industrial Equipment |
| 160 | 157.83 | 3000-6000 | T | EN16T | Heavy Duty Systems |
| 180 | 199.78 | 3000-6000 | T | EN16T | Mining Equipment |
| 200 | 246.60 | 3000-6000 | T | EN16T | Heavy Engineering |
| 220 | 298.39 | 3000-6000 | T | EN16T | Power Generation |
| 250 | 385.31 | 3000-6000 | T | EN16T | Large Industrial Equipment |
| 300 | 554.85 | 3000-6000 | T | EN16T | Forged Components |
| 350 | 755.62 | 3000-6000 | T | EN16T | Heavy Machinery |
| 400 | 986.40 | 3000-6000 | T | EN16T | Large Engineering Projects |
| 450 | 1248.42 | 3000-6000 | T | EN16T | Mining Systems |
| 500 | 1541.25 | 3000-6000 | T | EN16T | Heavy Industrial Applications |
EN19T (709M40T) Alloy Steel Round Bar
EN19T (709M40T) is a chromium-molybdenum alloy steel supplied in the hardened and tempered condition. It is one of the most widely used engineering steels in the UK due to its excellent combination of tensile strength, toughness, fatigue resistance, wear resistance, and machinability.
EN19T is commonly specified for hydraulic piston rods, drive shafts, gears, spindles, studs, bolts, couplings, mining equipment, and heavy engineering components. The chromium and molybdenum content provides improved hardenability and wear performance compared to EN16T, making it suitable for applications involving cyclic loading and higher stress levels.
Chargentum supplies EN19T alloy steel round bar in a comprehensive range of diameters with nationwide UK delivery.
| Diameter (mm) | Weight (kg/m) | Length (mm) | Condition | Grade | Typical Application |
|---|---|---|---|---|---|
| 20 | 2.47 | 3000-6000 | T | EN19T | Hydraulic Components |
| 25 | 3.85 | 3000-6000 | T | EN19T | High Tensile Fasteners |
| 30 | 5.55 | 3000-6000 | T | EN19T | Precision Shafts |
| 35 | 7.55 | 3000-6000 | T | EN19T | Engineering Pins |
| 40 | 9.87 | 3000-6000 | T | EN19T | Drive Shafts |
| 45 | 12.49 | 3000-6000 | T | EN19T | Couplings |
| 50 | 15.42 | 3000-6000 | T | EN19T | Spindles |
| 55 | 18.66 | 3000-6000 | T | EN19T | Hydraulic Rods |
| 60 | 22.20 | 3000-6000 | T | EN19T | Gear Components |
| 65 | 26.05 | 3000-6000 | T | EN19T | Industrial Components |
| 70 | 30.21 | 3000-6000 | T | EN19T | Mechanical Equipment |
| 75 | 34.69 | 3000-6000 | T | EN19T | Mining Equipment |
| 80 | 39.46 | 3000-6000 | T | EN19T | Heavy Machinery |
| 85 | 44.55 | 3000-6000 | T | EN19T | Drive Systems |
| 90 | 49.94 | 3000-6000 | T | EN19T | Power Transmission |
| 95 | 55.64 | 3000-6000 | T | EN19T | Engineering Components |
| 100 | 61.65 | 3000-6000 | T | EN19T | Heavy Engineering |
| 110 | 74.59 | 3000-6000 | T | EN19T | Power Generation |
| 125 | 96.33 | 3000-6000 | T | EN19T | Oil & Gas Equipment |
| 140 | 120.87 | 3000-6000 | T | EN19T | Industrial Systems |
| 150 | 138.72 | 3000-6000 | T | EN19T | Heavy Machinery |
| 160 | 157.83 | 3000-6000 | T | EN19T | Structural Equipment |
| 180 | 199.78 | 3000-6000 | T | EN19T | Mining Components |
| 200 | 246.60 | 3000-6000 | T | EN19T | Heavy Industrial |
| 220 | 298.39 | 3000-6000 | T | EN19T | Power Equipment |
| 250 | 385.31 | 3000-6000 | T | EN19T | Large Industrial Equipment |
| 300 | 554.85 | 3000-6000 | T | EN19T | Forged Components |
| 350 | 755.62 | 3000-6000 | T | EN19T | Heavy Engineering Projects |
| 400 | 986.40 | 3000-6000 | T | EN19T | Mining Systems |
| 450 | 1248.42 | 3000-6000 | T | EN19T | Industrial Machinery |
| 500 | 1541.25 | 3000-6000 | T | EN19T | Heavy Duty Applications |
EN24T (817M40T) Alloy Steel Round Bar
EN24T (817M40T) is a high-strength nickel-chromium-molybdenum alloy steel supplied in the hardened and tempered condition. It offers an outstanding combination of tensile strength, toughness, fatigue resistance, impact resistance, and hardenability, making it one of the most versatile engineering steels available.
The addition of nickel provides superior toughness and shock resistance compared with EN19T, while chromium and molybdenum enhance wear resistance and hardenability. EN24T is frequently specified for aerospace components, transmission systems, highly stressed shafts, gears, heavy-duty fasteners, defence equipment, motorsport applications, marine engineering, and critical load-bearing components.
Chargentum supplies EN24T round bar throughout the UK with mill certification, and nationwide delivery.
| Diameter (mm) | Weight (kg/m) | Length (mm) | Condition | Grade | Typical Application |
|---|---|---|---|---|---|
| 20 | 2.47 | 3000-6000 | T | EN24T | Aerospace Components |
| 25 | 3.85 | 3000-6000 | T | EN24T | Precision Engineering |
| 30 | 5.55 | 3000-6000 | T | EN24T | High Strength Shafts |
| 35 | 7.55 | 3000-6000 | T | EN24T | Aircraft Components |
| 40 | 9.87 | 3000-6000 | T | EN24T | Gear Shafts |
| 45 | 12.49 | 3000-6000 | T | EN24T | Couplings |
| 50 | 15.42 | 3000-6000 | T | EN24T | Transmission Systems |
| 55 | 18.66 | 3000-6000 | T | EN24T | Aerospace Fittings |
| 60 | 22.20 | 3000-6000 | T | EN24T | Aircraft Components |
| 65 | 26.05 | 3000-6000 | T | EN24T | High Load Components |
| 70 | 30.21 | 3000-6000 | T | EN24T | Engineering Systems |
| 75 | 34.69 | 3000-6000 | T | EN24T | Motorsport Components |
| 80 | 39.46 | 3000-6000 | T | EN24T | Marine Components |
| 85 | 44.55 | 3000-6000 | T | EN24T | Defence Components |
| 90 | 49.94 | 3000-6000 | T | EN24T | Heavy Duty Systems |
| 95 | 55.64 | 3000-6000 | T | EN24T | Precision Components |
| 100 | 61.65 | 3000-6000 | T | EN24T | Heavy Duty Shafts |
| 110 | 74.59 | 3000-6000 | T | EN24T | Power Transmission |
| 125 | 96.33 | 3000-6000 | T | EN24T | Marine Engineering |
| 140 | 120.87 | 3000-6000 | T | EN24T | Aerospace Structures |
| 150 | 138.72 | 3000-6000 | T | EN24T | Extreme Load Applications |
| 160 | 157.83 | 3000-6000 | T | EN24T | Defence Equipment |
| 180 | 199.78 | 3000-6000 | T | EN24T | Heavy Transmission Systems |
| 200 | 246.60 | 3000-6000 | T | EN24T | Critical Engineering Components |
| 220 | 298.39 | 3000-6000 | T | EN24T | Marine Systems |
| 250 | 385.31 | 3000-6000 | T | EN24T | Heavy Industrial Equipment |
| 300 | 554.85 | 3000-6000 | T | EN24T | Forged Components |
| 350 | 755.62 | 3000-6000 | T | EN24T | Aerospace Tooling |
| 400 | 986.40 | 3000-6000 | T | EN24T | Defence Applications |
| 450 | 1248.42 | 3000-6000 | T | EN24T | Marine Equipment |
| 500 | 1541.25 | 3000-6000 | T | EN24T | Heavy Engineering Projects |
Download Full Alloy Steel Datasheet
Download the complete technical datasheet for Alloy steel including:
- Chemical and mechanical properties
- Delivery conditions, tolerances, and finishes
- Full dimension, weight, and grade tables for round bars