At Ludhiana Steel Rolling Mills, we manufacture a focused range of chromium-manganese steel grades for forging, machining, case-hardening and engineering applications.
Enquire NowThe combination of chromium and manganese can improve hardenability, strength and response to heat treatment compared with simpler carbon steels. Within this category, some grades are particularly suited to carburised components, while others are used for stronger, heat-treated engineering parts.
Our current Chromium-Manganese Steel range includes 16MnCr5, 20MnCr5, 41Cr4, EN18, 34Cr4 and 40Cr4B.
Although these grades are grouped within the same product category, they do not all serve the same purpose.
For example, 16MnCr5 and 20MnCr5 are widely associated with case-hardening applications, while grades such as 41Cr4 and EN18 are used where higher strength and hardenability are required in engineering components.
The correct grade should therefore be selected according to the component, section size, heat-treatment route and applicable specification.
Available size range: 16mm to 230mm.
Round bars provide a practical starting form for machining, forging and subsequent heat treatment. Depending on the grade and component specification, they may be used for gears, shafts, pins, transmission parts and other engineered components.
Available size range: 28mm to 140mm.
RCS bars can be considered where the forging process benefits from a round-cornered square starting section.
Available size range: 18mm to 80mm.
Peeled bars provide a cleaner starting surface for precision machining and downstream component production.
Chromium and manganese both influence the way engineering steel responds to heat treatment.
Manganese can contribute to:
Chromium can support:
The exact effect depends on the grade chemistry and processing route. This is why Chromium-Manganese Steel should be specified by actual grade and standard, not simply by the category name.
16MnCr5 is an established case-hardening engineering steel. Its relatively low carbon content allows the material to retain a tougher core, while carburising and subsequent hardening can produce a harder outer surface. This combination makes it particularly relevant to components that experience both surface wear and transmitted mechanical loads.
Typical application areas can include:
For a 16MnCr5 requirement, it is useful to include the required case-hardening specification or finished-component drawing where available.
20MnCr5 belongs to the same broad manganese-chromium case-hardening family but has a different chemistry and hardenability profile. It is widely used for components requiring:
Common component requirements include gears, gear shafts, pinions, transmission parts, sprockets and other case-hardened components.
Although 16MnCr5 and 20MnCr5 are related, they should not be treated as automatically interchangeable. The selected grade should follow the applicable drawing and material standard.
41Cr4 is a chromium-alloy engineering steel used where stronger heat-treated properties and greater hardenability are required than in plain carbon steel.
Depending on the component and condition, it may be considered for applications such as shafts, axles, pins, machine components, gears and forged engineering parts.
The grade may be supplied for further machining and heat treatment according to the final component requirement.
EN18 is another established engineering grade within our Chromium-Manganese Steel category. It is suited to components where increased hardenability and strength are required while maintaining practical toughness for mechanical service.
Typical requirements can include shafts, axles, pins, spindles, forged parts and general engineering components.
Where EN18 appears on an older or customer-specific drawing, we recommend sending the complete material designation and standard rather than converting it to another grade before enquiry.
34Cr4 and 40Cr4B are chromium-bearing engineering grades used where the component requires greater strength and heat-treatment response than conventional carbon steels. These grades may be relevant to forged and machined parts subjected to mechanical loading.
For either grade, the enquiry should clearly specify:
That helps distinguish the actual performance requirement from the broader steel-family classification.
One of the most important applications within this category is case hardening. Grades such as 16MnCr5 and 20MnCr5 are designed so that the outer surface and inner core can perform different jobs. After carburising and hardening, the surface is designed for higher hardness and wear resistance, while the core retains greater toughness to support bending, torque and shock loads.
This combination is particularly useful for:
The required case depth, surface hardness and heat-treatment cycle should come from the component specification.
Several grades in this category can be supplied as starting material for forging. Depending on the component geometry, the preferred starting form may be:
A useful forging enquiry should include: Grade + Standard + Starting Size + Product Form + Quantity + Supply Condition + Final Component.
Providing the actual forged component helps the material requirement remain connected to the downstream manufacturing process.
These steels may undergo machining before or after selected heat-treatment operations, depending on the component route. Common operations include:
For case-hardening components, substantial machining is usually completed before the final surface-hardening stage.
Where a cleaner starting surface is useful, peeled-bar stock can be considered within our 18mm–80mm product range.
Heat treatment is especially important within the Chromium-Manganese Steel category because the grades can serve very different metallurgical purposes. Our heat-treatment infrastructure supports annealing, normalising and spheroidising.
Depending on the grade and downstream application, additional customer-controlled processes may include:
The final treatment route should always follow the material and component specification. We do not recommend applying one standard heat-treatment condition across all grades in this category.
Our Chromium-Manganese Steel requirements are supported by an integrated manufacturing route: Steel Melting → Ladle Refining → Vacuum Degassing → Continuous Casting → Rolling → Heat Treatment / Finishing → Inspection & Testing.
This gives us control over multiple production stages before the steel reaches your forging, machining or heat-treatment process.
For engineering grades that depend on chemistry and hardenability, maintaining control through steelmaking, refining and processing is particularly important.
Different grades may require different inspection criteria depending on the application. Our testing infrastructure includes facilities for:
For case-hardening steels, chemistry and hardenability can be especially important because they influence how the component responds during final heat treatment.
The actual acceptance criteria should be defined by the customer specification or applicable material standard.
16MnCr5 and 20MnCr5 are particularly relevant to case-hardened gears, pinions and transmission parts.
Chromium-manganese engineering steels can be used for forged and machined automotive components where the selected grade meets the required mechanical properties.
Round and RCS sections can provide starting material for forged engineering components.
Grades such as 41Cr4 and EN18 can be relevant where increased strength and hardenability are needed in mechanically loaded components.
The category also supports broader engineering applications where conventional carbon steel may not provide the required heat-treatment response or mechanical performance.
Our range includes both case-hardening and general engineering grades: 16MnCr5, 20MnCr5, 41Cr4, EN18, 34Cr4 and 40Cr4B.
Depending on grade and specification feasibility, requirements can be discussed in:
Our production route covers steelmaking, refining, casting, rolling, heat treatment, finishing and inspection.
You can approach us with a known material grade or with the component, drawing and heat-treatment requirement.
Our range includes 16MnCr5, 20MnCr5, 41Cr4, EN18, 34Cr4 and 40Cr4B.
Our round-bar range is 16mm to 230mm.
Our RCS range is 28mm to 140mm, subject to grade and specification feasibility.
Our peeled-bar range is 18mm to 80mm.
Within this category, 16MnCr5 and 20MnCr5 are widely associated with carburised and case-hardened engineering components.
They belong to the same manganese-chromium case-hardening family but have different chemistry and hardenability characteristics. Selection should follow the component specification rather than treating them as direct substitutes.
Yes. EN18 is an engineering steel used for mechanically loaded parts where increased strength and hardenability are required.
Yes. Share the drawing, application, required size, supply condition and heat-treatment requirement so the material requirement can be reviewed in context.
Send us your: Grade → Standard → Product Form → Size → Quantity → Supply Condition → Heat Treatment → Application.
If the material is intended for a gear, transmission part, shaft or other critical component, include the drawing or specification where available.
Leave your details and requirement. Our team will get back to you shortly.