Alloy Case Hardening & Spring Steel

Alloy Case Hardening & Spring Steel grades such as ,16MnCr5, 20MnCr5, SAE8620, 50CrV4, and 51CrV4 are widely used in industries that require superior durability, strength, and long-lasting performance. These alloys provide an excellent combination of toughness and wear resistance, making them suitable for automotive parts, engineering components, and heavy industrial machinery. Their balanced mechanical properties ensure reliable performance even under high pressure, friction, and continuous operational loads.

Case hardening grades 16MnCr5 and 20MnCr5 are specifically designed to develop a hard, wear-resistant outer surface while maintaining a tough and ductile core. This makes them ideal for manufacturing gears, shafts, cams, and transmission parts where both surface strength and internal toughness are essential. These steels respond very well to carburizing and heat treatment, ensuring consistent hardening depth and extended component life.

SAE8620, a premium nickel-chromium-molybdenum alloy steel, is widely preferred for precision-machined components requiring deep case hardening and excellent fatigue strength. It is commonly used in gears, pinions, bushings, automotive shafts, and a variety of heavy-duty engineering applications. The grade offers excellent machinability and uniform case depth, making it a reliable choice for industries that demand consistent performance under dynamic loads.

Spring steel grades 50CrV4 and 51CrV4 are recognized for their exceptional elasticity, high fatigue resistance, and ability to withstand repeated bending and shock loads. These chromium-vanadium alloys are used extensively in suspension systems, leaf springs, coil springs, tools, and other high-stress mechanical components. Their superior resilience and heat-treatment response make them perfect for applications that require stability, flexibility, and long-term durability.

For more information about Alloy Case Hardening & Spring Steel or to discuss using it in your application,
please contact Divyesh Shah +91 98201 27077, Keval Shah +91 99305 27077 or give us a call at 022 3151 8314

Alloy Case Hardening & Spring Steel Grades

• 16MnCr5 Case Hardening Steel
• 20MnCr5 – Case Hardening Steel
• SAE 8620 – Ni-Cr-Mo Case Hardening
• 50CrV4 – Chromium Vanadium Spring
• 51CrV4 – Chromium Vanadium Spring

Specification

Form : Bars, Rounds, Flats, Billets, Plates, Sheets, Coils
Delivery Conditions : Hot Rolled, Normalized, Annealed, Hardened & Tempered, Spheroidized Annealed
Thickness: 10 mm – 300 mm (Rounds & Bars) / 3 mm – 150 mm (Plates & Flats)
Width: Up to 2000 mm
Length: 3000 mm – 12000 mm (custom lengths available)
Surface Condition: Black Hot Rolled, Peeled, Bright Drawn, Polished, Ground, Machined

Equivalent Grades Chemical Properties Mechanical Properties

Grade	Standards / Equivalents	IS (India)	DIN (Germany)	EN (Europe)	JIS (Japan)	Key Applications in Steel Industry
16MnCr5	Case-hardening steel (Mat. No. 1.7131/1.7139)	16MnCr5	16MnCr5	EN10084	–	Gears, bushings, camshafts, connecting rods; surface hardened with tough core
50CrV4	Spring steel, high fatigue resistance	50CrV4 (EN47)	50CrV4	EN47	SUP10 (approx.)	Springs, automotive suspension, high-stress machine components
SAPH 440	Automotive structural steel	SAPH 440	–	–	SAPH 440	Automotive body & chassis parts, crash-resistant structures, stamping
SPFH 590	High-strength automotive structural steel	SPFH 590	–	–	SPFH 590	High-strength automotive components, chassis reinforcements, crash parts
SCM 435	Cr-Mo alloy steel for bolts & shafts	–	34CrMo4	EN10297	SCM435	Stud bolt

Grade	C (Carbon)	Mn (Manganese)	Si (Silicon)	P (max)	S (max)	Cr	B (Boron)	Fe (Balance)
16MnCr5	0.14 – 0.19	1.00 – 1.30	≤ 0.40	≤ 0.025	≤ 0.035	0.80 – 1.10
50CrV4	0.47 – 0.55	0.70 – 1.10	0.40 – 0.80	≤ 0.025	≤ 0.035	0.90 – 1.20
IF Grade	≤ 0.005	0.15 – 0.30	≤ 0.03	very low	very low
SAPH 440	≤ 0.16	≤ 1.60	≤ 0.50	≤ 0.030	≤ 0.025
SPFH 590	≤ 0.18	≤ 1.70	≤ 0.50	≤ 0.030	≤ 0.025
SCM 435	0.33 – 0.38	0.60 – 0.90	0.15 – 0.35	≤ 0.030	≤ 0.030	0.90 – 1.20

Grade	Yield Strength (MPa)	Tensile Strength (MPa)	Elongation (%)	Hardness /(HBW) Other Notes
16MnCr5	300 – 400	600 – 800	12 – 15	Case hardened: 58–62 HRC
50CrV4	800 – 1000	1000 – 1200	8 – 12	QT: 48–54 HRC
IF Grade	140 – 210	270 – 350	38 – 45	Excellent formability
SAPH 440	≥ 440	570 – 720	≥ 21	Structural automotive steel
SPFH 590	≥ 590	650 – 830	≥ 18	High-strength automotive
SCM 435	530 – 640	850 – 1000	12 – 16	QT: 30–36 HRC

Applications Industries

Railway & Transportation

Automotive Components

Agricultural Equipment

Construction & Earthmoving Equipment

Defense & Aerospace Components

Mining & Heavy Engineering