708M40 / EN19T Alloy Steel
High tensile strength, good machinability and weldability.
708M40 / EN19T Alloy Steel
708M40 (EN19T) is a high-quality low alloy engineering steel renowned for its excellent combination of strength, toughness, and wear resistance. It is widely used across engineering, automotive, and industrial sectors where reliable performance under stress is a priority.
This versatile material is suitable for components that are subject to high loads, impact, and abrasion, and can be further enhanced through heat treatment processes such as flame hardening and nitriding for increased surface durability.
| C | Si | Mn | S | P | Cr | Ni* | Mo | |
|---|---|---|---|---|---|---|---|---|
| Min | 0.36 | 0.10 | 0.70 | 0.90 | 0.15 | |||
| Max | 0.44 | 0.35 | 1.00 | 0.040 | 0.035 | 1.20 | 0.40 | 0.25 |
(* denotes residual element)
| Test Type | Tensile and Hardness test (at room temperature) | Impact test (KV) | ||||||
|---|---|---|---|---|---|---|---|---|
| Yield (Re) | 0.2% proof | UTS (Rm) | Elong (A) | R of A (Z) | Hardness | Room Temp | ||
| unit | N/mm2 | N/mm2 | N/mm2 | % | % | HB | J | |
| Annealed | Min | |||||||
| Max | 235 | |||||||
| Q + T + Drawn, condition 'T' | Min | 700 | 850 | 9 | 248 | 50 | ||
| Max | 1000 | 302 | ||||||
| Q + T to condition 'Q' | Min | 480 | 625 | 18 | 179 | 16 | ||
| Max | 775 | 229 | ||||||
| Q + T to condition 'R' | Min | 495 | 700 | 15 | 201 | 28 | ||
| Max | 850 | 255 | ||||||
| Q + T to condition 'S' | Min | 585 | 775 | 15 | 223 | 50 | ||
| Max | 925 | 277 | ||||||
| Q + T to condition 'T' | Min | 680 | 850 | 13 | 248 | 50 | ||
| Max | 1000 | 302 | ||||||
Common Applications
Thanks to its mechanical properties and heat treatability, 708M40 / EN19T is widely used in:
-
Gear shafts and transmission parts
-
Crankshafts and connecting rods
-
Axles and spindles
-
High-performance fasteners and bolts
-
Automotive components and drive train systems
-
Oil & gas sector components
-
Machine tool spindles
-
General-purpose high-strength engineering parts
Heat Treatment Options
-
Hardened & Tempered (T Condition): Ideal for components that require strength, wear resistance, and dimensional stability post-machining.
-
Soft Annealed Condition: Suitable for in-house heat treatment and offers improved machinability, especially for complex or precision-engineered parts.
Key Features and Benefits
-
High Tensile Strength: Supplied in the hardened and tempered ‘T’ condition, 708M40 delivers a tensile strength in the range of 850–1000 N/mm², providing robust performance in critical load-bearing components.
-
Excellent Ductility and Shock Resistance: Its balanced mechanical properties make it highly suitable for components exposed to dynamic forces, impacts, or torsional stress.
-
Wear Resistance: The wear resistance of this steel can be significantly improved through surface hardening techniques, extending component lifespan in demanding environments.
-
Versatile Machinability: Whether supplied in the hardened & tempered or softened condition, 708M40 machines well, reducing production time and post-treatment requirements.
-
Heat Treatment Flexibility: Supplied in either hardened and tempered or soft annealed form, this steel can be tailored to suit a wide range of mechanical applications and machining strategies.
• Grade 7-8M40
• Condition: Untreated/ Annealed/ Quench and tempered
• Surface Finish: As rolled/ As forged/ Bright drawn/ Bright turned
• Standard: BS970
• Applications: Axle shafts, crankshafts, gears, induction hardened pins
| Size Range Summary | ||
|---|---|---|
| Rounds | IMP | 3/8" - 3" dia |
| MM | 10mm - 310mm dia | |
| Properties | |
|---|---|
| MACHINEABILITY | 40 |
| WELDABILITY | Pre / post heat precaution required |
| HARDENABILITY | High strength up to 100mm dia |
| SELECTION GUIDEAND USAGE EXAMPLES | Popular direct hardening steel with good tensile. ductility, shock and wear resistance properties |
Industry Standards
708M40 conforms to the following standards and specifications:
-
British Standard: BS 970: 708M40
-
European Equivalent: 42CrMo4
-
Werkstoff Number: 1.7225
-
ISO Equivalent: ISO 683-1
Material test certificates (MTCs) and compliance documentation are available to ensure full traceability and peace of mind.
At Midland Special Steels, we offer a complete range of processing services to help you get the most out of your material:
-
Cut to length
-
Saw cutting and profile burning
-
Centreless grinding
-
Heat treatment services
-
Ultrasonic and non-destructive testing
-
Bespoke stockholding and scheduled deliveries
Midland Special Steels stocks a wide range of EN19T / 708M40 alloy steel bars in various diameters and lengths. Whether you require standard lengths or precision-cut material, we can deliver to your specification — quickly and reliably.
