🟪 Product Overview

Alloy Structural Steel Plate is engineered for high strength, toughness, hardenability, and fatigue resistance. Compared with mild structural steel, alloy steel plates offer:

• Higher mechanical strength
• Better wear resistance
• Superior heat‑treating performance
• Excellent fatigue resistance
• Ideal for precision engineering and heavy‑duty applications

These steels are widely used in machinery manufacturing, automotive components, mining equipment, and engineering structures.

🟪 Key Features

• High tensile and yield strength
• Excellent hardenability (suitable for quenching & tempering)
• Good fatigue resistance
• Suitable for machining and heat treatment
• Ideal for high‑load mechanical components

🟪 Included Grades

This page covers all major alloy structural steel grades:

ASTM / SAE Grades

• 4135
• 4140
• 4142
• 6150

EN Grades（EU）

• 42CrMo4
• 50CrMo4
• 51CrV4
• 20MnB5
• 27MnCrB5‑2

GB Grades（China）

• 20CrMo
• 30CrMo
• 35CrMo
• 42CrMo

🟪 Mechanical Properties (Typical)

Grade	Yield Strength	Tensile Strength	Hardness (Q&T)
4140	≥415 MPa	655–895 MPa	28–32 HRC
42CrMo4	≥450 MPa	800–1100 MPa	28–36 HRC
50CrMo4	≥550 MPa	900–1200 MPa	30–40 HRC
35CrMo	≥490 MPa	740–930 MPa	28–32 HRC

🟪 Chemical Composition (Typical)

Grade	C (%)	Mn (%)	Cr (%)	Mo (%)	V (%)
4140	0.38–0.43	0.75–1.00	0.80–1.10	0.15–0.25	—
42CrMo4	0.38–0.45	0.60–0.90	0.90–1.20	0.15–0.30	—
50CrMo4	0.45–0.55	0.60–0.90	0.90–1.20	0.15–0.30	—
51CrV4	0.47–0.55	0.70–1.10	0.90–1.20	—	0.10–0.25

🟪 Product Specifications

Thickness

• 6 – 200 mm

Width

• 1500 – 3000 mm

Length

• Custom lengths available

Delivery Conditions

• Hot Rolled
• Normalized
• Quenched & Tempered

🟪 Applications

Machinery Manufacturing

• Shafts
• Gears
• Connecting rods
• Crankshafts

Automotive Components

• Axles
• Transmission parts
• Suspension components

Engineering & Heavy Equipment

• Mining machinery
• Excavator parts
• Drilling equipment

Industrial Fabrication

• High‑load structural parts
• Wear‑resistant components

🟪 Why Choose WelSteels

• Full range of alloy structural steel grades
• Heat‑treatable high‑strength materials
• Precision cutting and processing
• SGS / BV inspection
• Export‑grade seaworthy packaging