16MnCrB5 alloy steel

Introduction

We manufacture forging ingots, billets, and blooms in alloy steel specifically for 16MnCrB5, developed for applications requiring high surface hardness, excellent wear resistance, and improved hardenability compared to standard 16MnCr5.

16MnCrB5 is a low carbon manganese-chromium-boron alloy steel primarily used for case hardening applications. The addition of a controlled amount of boron significantly enhances hardenability, allowing more uniform hardening and better performance in thicker sections, while maintaining a tough and ductile core.

This grade offers good machinability in the annealed condition and excellent response to carburizing and heat treatment. Due to its consistent performance and cost effectiveness, 16MnCrB5 is widely used in automotive, transmission, and heavy-duty engineering components.

Chemical composition

Element	Content (%)	Function / effect
Carbon (c)	0.14 – 0.19	Ensures tough core properties
Manganese (mn)	1.00 – 1.30	Improves hardenability and toughness
Silicon (si)	Max 0.40	Increases strength
Chromium (cr)	0.80 – 1.10	Improves hardenability and wear resistance
Boron (b)	0.0005 – 0.0030	Significantly enhances hardenability
Phosphorus (p)	Max 0.035	Impurity; controlled for toughness
Sulphur (s)	Max 0.035	Impurity; controlled for machinability

Mechanical properties (typical, depending on condition & heat treatment)

• Core tensile strength: 600 – 800 MPa
• Core yield strength: 400 – 600 MPa
• Surface hardness (carburized): 58 – 62 HRC
• Core hardness: 170 – 220 HB
• Impact toughness: Good

Heat treatment

• Annealing: improves machinability before carburizing.
• Carburizing: addition of carbon at high temperature to achieve a hard, wear-resistant surface.
• Quenching: rapid cooling to obtain hard martensitic case with improved depth due to boron.
• Tempering: relieves internal stresses while maintaining surface hardness and core toughness.

Boron addition enables effective hardening even in larger cross-sections.

Key features and benefits

• Enhanced hardenability due to boron addition
• Hard, wear-resistant surface with tough core
• More uniform case depth than 16MnCr5
• Good machinability in annealed condition
• Cost-effective alternative to ni-cr case hardening steels
• Suitable for forging and machining

Typical applications

• Gears and pinions
• Transmission and differential components
• Automotive and tractor parts
• Shafts and camshafts
• Heavy-duty engineering components subjected to wear

Equivalent steel grades

16MnCrB5 has limited direct international equivalents. Comparable grades include:

• En 10084 – 16MnCr5 (boron modified)
• Din 1.7139 (boron alloyed)
• SAE boron case hardening steels – application based

(exact equivalence depends on boron control and heat treatment)

Why choose 16MnCrB5 for your application?

16MnCrB5 offers the same base chemistry as 16MnCr5 with the advantage of boron-enhanced hardenability. This makes it ideal for components requiring deeper and more uniform case hardening without increasing alloy content or cost significantly.

Comparison table for similar grades

Grade	Carbon (%)	Key applications	Heat treatment	Comments
16MnCrB5	0.14 – 0.19	Gears, transmission parts	Carburizing + q&t	Boron-enhanced hardenability
16MnCr5	0.14 – 0.19	Gears, pinions	Carburizing	No boron
20mnCr5	0.17 – 0.23	Heavy-duty gears	Carburizing	Higher core strength
En36	0.12 – 0.18	Heavy-load gears	Carburizing	Ni-cr steel
SAE 5120	0.18 – 0.23	Automotive parts	Carburizing	Us comparable grade

Summary

16MnCrB5 is a low carbon manganese-chromium-boron alloy steel designed for case hardening applications. It provides a hard, wear-resistant surface, a tough core, and improved hardenability for demanding automotive and engineering applications.