Quick Specification Overview

Alternative Spellings and Transliteration

15KH Grade Names

The following names generally refer to the Russian grade 15Х:

• 15KH steel
• 15X steel
• 15Kh steel
• 15Ch steel
• 15Х steel
• Russian grade 15KH
• сталь 15Х
• конструкционная сталь 15Х
• легированная сталь 15Х
• хромистая сталь 15Х
• цементуемая сталь 15Х

20KH Grade Names

The following names generally refer to the Russian grade 20Х:

• 20KH steel
• 20X steel
• 20Kh steel
• 20Ch steel
• 20Х steel
• Russian grade 20KH
• сталь 20Х
• конструкционная сталь 20Х
• легированная сталь 20Х
• хромистая сталь 20Х
• цементуемая сталь 20Х

The Latin letter X in names such as 15X and 20X is a transliteration of the Cyrillic Х. It should not be interpreted as a dimensional multiplication symbol.

Grade Designation Breakdown

What Does 15KH or 15Х Mean?

In the Russian designation 15Х:

• 15 indicates a nominal carbon content of approximately 0.15%.
• Х indicates chromium as the principal alloying element.
• The absence of a number after Х generally indicates that the chromium content is around 1%.

The result is a low-carbon chromium steel designed for carburizing and case-hardening operations.

What Does 20KH or 20Х Mean?

In the Russian designation 20Х:

• 20 indicates a nominal carbon content of approximately 0.20%.
• Х identifies chromium as the principal alloying element.
• The chromium content is normally below or around 1%.

Compared with 15KH, the higher carbon content of 20KH generally supports greater core strength after heat treatment.

Steel Classification

Both 15KH and 20KH are classified as chromium-alloyed structural engineering steels. They are commonly selected as:

• Case-hardening steel
• Carburizing steel
• Low-carbon or low-alloy chromium steel
• Structural alloy steel
• Engineering steel
• Wear-resistant steel after surface hardening
• Steel for components requiring a hard surface and tough core

These grades are not selected only for their untreated hardness. Their principal engineering benefit is achieved through a controlled combination of carburizing, quenching and tempering.

15KH (15X / 15Х) Steel Specifications

15KH Steel Description

15KH steel, also written as 15X, 15Kh, 15Ch or 15Х, is a Russian low-carbon chromium structural steel used for carburized and case-hardened components.

Its relatively low carbon content supports a tough core, while carburizing introduces additional carbon into the surface layer. After quenching and tempering, the component can develop high surface hardness and improved wear resistance without making the entire section excessively brittle.

Russian Metals supplies 15KH material for mechanical engineering, automotive components, general industrial machinery and custom-machined parts.

15KH Chemical Composition

Chemical Composition in Percentage for 15KH (15Х)

The combination of low carbon and chromium makes 15KH suitable for parts that must retain core toughness while developing a hardened surface.

Critical Transformation Temperatures of 15KH

These critical temperatures provide metallurgical reference points for developing annealing, normalizing, austenitizing and quenching procedures. Actual production temperatures should be selected according to component size, furnace type, required case depth and applicable specification.

15KH Mechanical Properties

Mechanical Properties at 20°C

Mechanical properties vary according to product form, cross-section, heat treatment, testing direction and applicable standard. Purchase specifications should identify the required condition and acceptance values.

15KH Physical Properties

At room temperature, the reported 15KH density is approximately 7,830 kg/m³. Physical-property values are temperature-dependent and should be used with the relevant engineering design factors.

15KH Hardness Information

The table contains hardness values for the listed delivery conditions. Surface hardness after carburizing will be substantially affected by carbon potential, case depth, quenching medium, tempering temperature and part geometry.

Surface Hardness After Carburizing

15KH is commonly selected where the finished component needs:

• A hard carburized surface
• Improved resistance to sliding and rolling wear
• Better resistance to local contact stress
• A comparatively tough and lower-carbon core
• Reduced risk of through-section brittleness

The required 15KH surface hardness should be stated on the drawing or purchase specification. It should not be assumed from the base-grade designation alone.

Core Strength and Toughness

The low carbon range of 15KH helps retain core toughness after surface hardening. This makes the grade useful for relatively small gears, pins, spindles, rollers, bushings and similar components exposed to surface wear and moderate impact loading.

Core properties depend on:

• Effective section thickness
• Austenitizing temperature
• Quenching severity
• Tempering cycle
• Grain size
• Carburized case depth
• Final machining and grinding

15KH Equivalent Grades

International Comparison Table

15KH and SAE 5015 Comparison

SAE 5015 is frequently listed as a comparison for 15KH because both are low-carbon chromium steels. However, chemical limits, residual elements, hardenability requirements, product standards and test conditions can differ.

15KH and AISI 5115 Comparison

AISI 5115 is another commonly referenced comparison. It may be suitable as a functional alternative in some applications, but substitution should be based on:

• Full chemical composition
• Hardenability requirements
• Required case depth
• Core hardness
• Surface hardness
• Mechanical-property requirements
• Product dimensions
• Applicable customer standard

15KH and DIN 15Cr3 Comparison

DIN 15Cr3 and material number 1.7015 are frequently compared with Russian 15KH. Before approving 15KH as a 15Cr3 Russian equivalent, the design authority should review the applicable standard revision and heat-treatment requirements.

15KH and JIS SCr415 Comparison

JIS SCr415 is a Japanese chromium case-hardening steel commonly compared with 15KH. The two grades have similar intended applications, but they should not be substituted solely on the basis of grade names.

15KH Carburizing Process

Carburizing increases the carbon concentration in the outer layer of a 15KH component. The part is subsequently quenched and tempered to obtain a hard case and tough core.

A controlled carburizing process should consider:

• Required effective case depth
• Surface carbon target
• Furnace atmosphere
• Carburizing duration
• Component geometry
• Distortion allowance
• Quenching method
• Grinding allowance
• Final surface-hardness requirement

The correct 15KH carburizing temperature and cycle must be established by the heat-treatment specification rather than selected from the grade name alone.

15KH Case-Hardening Details

Case hardening is especially useful for parts exposed to concentrated contact loads. For reliable performance, buyers should specify:

• Total case depth
• Effective case depth
• Surface-hardness range
• Core-hardness range
• Test location
• Microstructure requirement
• Retained-austenite limit, where applicable
• Decarburization limit
• Distortion tolerance

Russian Metals can supply 15KH material for subsequent carburizing and machining based on customer drawings and material specifications.

15KH Annealing Information

Annealed 15KH is commonly selected where improved machinability or preparation for further forming is required. The reported annealed hardness under GOST 4543-71 is HB 179.

The final annealing cycle should be selected according to starting condition, section thickness and the required microstructure.

15KH Normalizing Information

The supplied mechanical-property data includes normalized forgings up to 300 mm. Normalizing can refine the microstructure and provide a more uniform condition before machining or additional heat treatment.

15KH Quenching Details

A reported heat-treatment cycle for a 15 mm bar includes:

1. Quenching from approximately 880°C in water.
2. Secondary quenching from approximately 770–820°C in water.
3. Tempering at approximately 180°C followed by air cooling.

This treatment must not be applied blindly to every component. Larger sections and complex geometries may require a modified procedure to control cracking and distortion.

15KH Tempering Details

Low-temperature tempering after quenching can reduce quenching stresses while retaining high surface hardness. The required tempering temperature depends on the target surface hardness, core condition and dimensional-stability requirement.

15KH Hardenability

Chromium improves the hardenability of 15KH compared with unalloyed steels of a similar carbon level. Nevertheless, 15KH is generally better suited to small and moderate component sections than to very large parts requiring high through-hardness.

15KH Wear and Abrasion Resistance

The untreated steel should not be evaluated as a fully wear-resistant grade. Its wear resistance is developed mainly through:

• Carburizing
• Quenching
• Low-temperature tempering
• Controlled case depth
• Suitable surface finishing
• Correct lubrication during service

15KH Fatigue Resistance

A properly carburized 15KH component can provide useful contact-fatigue and bending-fatigue performance. Actual fatigue life depends on surface finish, case depth, hardness gradient, residual stress, inclusions, notches and loading conditions.

15KH Welding Information

The supplied technological data classifies 15KH weldability as without limitations. It is also listed as:

Production welding should still use an approved welding procedure. Preheating, filler selection and post-weld treatment may be required for thick sections, highly restrained joints or previously carburized components.

15KH Machining and Fabrication

15KH can be machined in an annealed or normalized condition before carburizing and final hardening. A typical production sequence may include:

1. Cutting the bar, plate or forging blank.
2. Rough machining.
3. Stress relief where required.
4. Carburizing.
5. Quenching and tempering.
6. Finish grinding.
7. Hardness and case-depth inspection.

Final machining allowance should account for distortion and surface finishing after heat treatment.

Available 15KH Product Forms

Russian Metals can supply or arrange production of:

• 15KH round bar
• 15X round bar
• 15KH forged round bar
• 15KH bright bar
• 15KH steel rod
• 15KH flat bar
• 15KH steel plate
• 15KH steel sheet
• 15KH steel strip
• 15KH seamless pipe
• 15KH steel tube
• 15KH forging
• 15KH wire
• 15KH custom forgings
• круг 15Х
• пруток 15Х
• кованый круг 15Х
• лист 15Х
• плита 15Х
• полоса 15Х
• лента 15Х
• труба 15Х
• бесшовная труба 15Х
• проволока 15Х
• поковка 15Х

Available 15KH Sizes and Dimensions

Available dimensions depend on the required product form, production route and current stock position. Russian Metals can support enquiries for:

• Standard mill dimensions
• Cut-to-length bars
• Saw-cut blanks
• Rough-machined blanks
• Custom forged sizes
• Small and large diameters
• Plate and sheet thicknesses
• Tube outside diameters and wall thicknesses
• Customer-specific tolerances

Required diameter, thickness, width, length, tolerance and quantity should be stated with the enquiry.

Main Applications of 15KH Steel

15KH is commonly considered for:

• Bushings
• Pins
• Spindles
• Small gears
• Rollers
• Shafts
• Camshafts
• Machine components
• Carburized parts
• Case-hardened components
• Wear-resistant parts
• Automotive components
• Mechanical-engineering parts
• Components requiring a hard surface and tough core

20KH (20X / 20Х) Steel Specifications

20KH Steel Description

20KH steel, also written as 20X, 20Kh, 20Ch or 20Х, is a Russian chromium-alloyed structural steel used for carburized gears, shafts and other case-hardened engineering components.

Compared with 15KH, 20KH contains a higher nominal carbon level. This can provide increased core strength after suitable heat treatment while still allowing the surface to be carburized and hardened.

Russian Metals supplies 20KH material for automotive, transmission, machinery, general engineering and industrial equipment applications.

20KH Chemical Composition

Chemical Composition in Percentage for 20KH (20Х)

The higher carbon and manganese ranges distinguish 20KH from 15KH and contribute to its strength and response to heat treatment.

Critical Transformation Temperatures of 20KH

These values are metallurgical reference points. The final heat-treatment schedule should be approved for the actual component size and required mechanical properties.

20KH Mechanical Properties

Mechanical Properties at 20°C

The values apply only to the indicated product and test condition. Properties for a larger 20KH round bar, forging, plate or tube may differ.

20KH Physical Properties

At room temperature, the reported 20KH density is approximately 7,830 kg/m³.

20KH Hardness Information

The cold-worked hardness of 20KH is reported as higher than that of 15KH. Final carburized hardness must be separately specified and tested.

Surface Hardness After Carburizing

20KH is used for components requiring high surface hardness, improved wear resistance and stronger core support. The final result depends on:

• Surface carbon content
• Effective case depth
• Quenching process
• Tempering cycle
• Component section
• Surface finishing
• Grinding and inspection procedures

Core Strength and Toughness

The nominal carbon level of 20KH is higher than that of 15KH. Under comparable processing conditions, this can support higher core strength, making 20KH suitable for gears, gear shafts and transmission components.

The final core hardness must still be confirmed by testing because it is affected by section size, hardenability and heat-treatment severity.

20KH Equivalent Grades

International Comparison Table

20KH and AISI 5120 Comparison

AISI 5120 is one of the most frequently referenced comparisons for 20KH. Both are chromium case-hardening steels used for gears, shafts and automotive components.

However, 20KH should not automatically be certified as AISI 5120 unless the supplied heat satisfies the required chemical, mechanical and hardenability limits.

20KH and DIN 20Cr4 Comparison

DIN 20Cr4 and EN material number 1.7027 are commonly associated with 20KH equivalent searches. Their use as substitutes should be based on a complete technical comparison rather than only the nominal carbon and chromium levels.

20KH and JIS SCr420 Comparison

JIS SCr420 is a Japanese chromium case-hardening steel frequently compared with 20KH. Both can be used for carburized mechanical components, but standard-specific requirements may differ.

20KH Compared with 16MnCr5 and 20MnCr5

16MnCr5 and 20MnCr5 contain a manganese-chromium alloying system and generally provide a different hardenability response from 20KH. They may be considered as functional alternatives in some components, but they are not direct grade-name equivalents.

20KH Carburizing Process

The carburizing process enriches the outer surface of 20KH with carbon before quenching and tempering. This treatment is used to create a high-hardness case supported by a stronger core.

The process specification should define:

• Carburizing temperature
• Carbon potential
• Carburizing duration
• Diffusion stage
• Total case depth
• Effective case depth
• Quenching temperature
• Quenching medium
• Tempering temperature
• Final hardness range

20KH Case-Hardening Details

20KH case-hardening steel is particularly suitable for parts subjected to rolling contact, sliding contact or tooth loading. Correct case-hardening control helps reduce premature wear, pitting and surface deformation.

Excessive case depth or an unsuitable hardness gradient can increase distortion or cracking risk. Heat-treatment parameters must therefore be matched to the component geometry.

20KH Annealing Information

Annealed 20KH has a reported hardness of HB 179 under GOST 4543-71. The annealed condition is suitable for machining and preparation before carburizing or final heat treatment.

20KH Normalizing Information

Normalizing may be used to refine the structure of forgings or hot-worked products before machining. The exact normalizing temperature and cooling method should be stated in the manufacturing procedure.

20KH Quenching Details

The supplied 20KH bar data identifies a quenched-and-tempered condition but does not provide a universal temperature cycle. Quenching temperature and medium must be selected according to:

• Part dimensions
• Required core hardness
• Case depth
• Distortion tolerance
• Furnace atmosphere
• Prior microstructure

20KH Tempering Details

Tempering reduces residual stresses after quenching and adjusts the final balance of hardness and toughness. Low-temperature tempering is commonly associated with carburized parts where high case hardness must be retained.

20KH Hardenability

The chromium addition improves the hardenability of 20KH compared with a plain-carbon steel of a similar carbon content. For heavy sections or demanding core-hardness requirements, hardenability testing and trial heat treatment may be necessary.

20KH Wear and Abrasion Resistance

A properly carburized and hardened 20KH component can provide:

• High surface hardness
• Improved adhesive-wear resistance
• Improved abrasive-wear resistance
• Better resistance to contact deformation
• Useful performance in lubricated gear systems

Performance depends on case quality and should not be judged from bulk hardness alone.

20KH Fatigue Resistance

Carburizing can improve the fatigue behaviour of 20KH components by creating a hard surface layer and beneficial residual-compressive stresses. Poor grinding, sharp radii, decarburization or excessive retained austenite can reduce this benefit.

20KH Welding Information

The supplied technological classification states:

Despite this classification, welding a finished carburized component is generally undesirable because it can damage the hardened case. Welding should preferably be completed before final heat treatment.

20KH Machining and Fabrication

20KH can be machined in the annealed or normalized condition. Recommended manufacturing planning should consider:

• Tooling for chromium-alloy steel
• Stock allowance for heat-treatment distortion
• Grinding allowance
• Case-depth measurement location
• Final surface finish
• Inspection after heat treatment

Available 20KH Product Forms

Russian Metals can supply or arrange production of:

• 20KH round bar
• 20X round bar
• 20KH forged round bar
• 20KH bright bar
• 20KH steel rod
• 20KH flat bar
• 20KH steel plate
• 20KH sheet
• 20KH steel strip
• 20KH seamless pipe
• 20KH steel tube
• 20KH forging
• 20KH wire
• 20KH custom forgings
• круг 20Х
• пруток 20Х
• кованый круг 20Х
• лист 20Х
• плита 20Х
• полоса 20Х
• лента 20Х
• труба 20Х
• бесшовная труба 20Х
• проволока 20Х
• поковка 20Х

Available 20KH Sizes and Dimensions

Supply can be arranged according to the required product form and order quantity. Available options may include:

• Standard diameter round bars
• Forged bars
• Cut-to-size steel
• Machining blanks
• Plates and sheets
• Seamless pipes and tubes
• Custom forgings
• Customer-specific lengths
• Special tolerances
• Small or bulk production quantities

Stock availability must be confirmed against the requested size, quantity and delivery condition.

Main Applications of 20KH Steel

20KH is commonly considered for:

• Gears
• Gear shafts
• Shafts
• Bushings
• Pins
• Rollers
• Cams
• Piston pins
• Automotive components
• Transmission parts
• Machine components
• Carburized parts
• Case-hardened components
• Wear-resistant components
• Components requiring high surface hardness
• Components requiring a hard case and tough core

15KH vs 20KH Steel Comparison

Main Difference Between 15KH and 20KH

Choose 15KH where a lower-carbon core and toughness are important. Choose 20KH where the design requires greater core strength after treatment. The final decision should be based on component size, loading, case-depth requirement and heat-treatment capability.

Applicable GOST Standards

Depending on the product form and order requirement, the following standards may be relevant:

The exact standard edition, delivery condition and supplementary requirements should be written on the purchase order.

Industries Served

Russian Metals supplies alloy and engineering steel for industries such as:

• Automotive manufacturing
• Gear manufacturing
• Mechanical engineering
• Industrial machinery
• Transmission manufacturing
• Agricultural equipment
• Mining equipment
• Material-handling equipment
• General fabrication
• Tool and die operations
• Oil and gas equipment
• Railway engineering
• Defence-related manufacturing where approved
• Export-oriented component manufacturing

Material Testing and Inspection

Testing can be arranged according to the material specification and purchase order. Requirements may include:

• Chemical-composition analysis
• Tensile testing
• Yield-strength testing
• Elongation testing
• Impact testing
• Brinell hardness testing
• Ultrasonic testing
• Dimensional inspection
• Surface inspection
• Positive material identification
• Macrostructure examination
• Microstructure examination
• Decarburization testing
• Hardenability testing
• Case-depth measurement
• Surface and core-hardness testing

Testing requirements must be agreed before production or material dispatch.

MTC and EN 10204 3.1 Certification

15KH and 20KH material can be supplied with a material test certificate where available and agreed. Documentation may include:

• Heat number
• Grade designation
• Product dimensions
• Chemical composition
• Mechanical properties
• Heat-treatment condition
• Applicable specification
• Inspection status

An EN 10204 3.1 certificate may be requested for applicable orders. Certification availability depends on the material source, product form and inspection arrangement.

Packaging and Export Documentation

Export and domestic packaging can be selected according to the product form and transport method. Options may include:

• Bundled bars
• Steel-strapped bundles
• Wrapped bright bars
• Protected machined surfaces
• Wooden boxes or crates
• End-protected tubes
• Rust-preventive coating
• Identification tags
• Heat-number marking
• Packing list
• Commercial invoice
• Certificate of origin where required
• Material test certificate
• Inspection documents

15KH and 20KH Supplier in India

Russian Metals supplies Russian and international engineering steel grades to customers in India and export markets. Enquiries can be handled for:

• 15KH steel supplier India
• 15X steel supplier India
• 20KH steel supplier India
• 20X steel supplier India
• 15KH and 20KH steel stockist Mumbai
• Alloy steel supplier Maharashtra
• GOST 4543 steel supplier
• Case-hardening steel supplier
• Carburizing steel supplier
• Chromium steel supplier
• Round bar supplier India
• Forged bar supplier India
• Steel plate supplier
• Seamless pipe and tube supplier
• Custom forging supplier
• Material with MTC
• Cut-to-size engineering steel

Stock Availability and Custom Supply

Stock position varies according to grade, form, diameter, thickness and quantity. Russian Metals can evaluate requirements for ready stock, mill production or custom forging.

For an accurate offer, the material enquiry should include:

• Grade: 15KH, 15X, 15Х, 20KH, 20X or 20Х
• Applicable standard
• Required product form
• Diameter or thickness
• Width and length
• Quantity
• Heat-treatment condition
• Required mechanical properties
• Testing requirements
• Certification requirement
• Delivery location
• Required delivery schedule

15KH and 20KH Price per Kilogram in India

The 15KH price per kg and 20KH price per kg depend on:

• Product form
• Material size
• Order quantity
• Forged or rolled production route
• Heat-treatment condition
• Machining requirement
• Testing and inspection
• Certification
• Packaging
• Freight
• Current raw-material and production costs

A fixed price should not be published without identifying the exact dimension and supply condition.

Russian-Language Grade Summary

Сталь 15Х

Сталь 15Х — конструкционная легированная хромистая сталь, применяемая для изготовления цементуемых деталей. После цементации, закалки и отпуска сталь может обеспечить высокую твердость поверхности при сохранении вязкой сердцевины.

Основные области применения 15Х:

• втулки;
• пальцы;
• шпиндели;
• небольшие шестерни;
• ролики;
• валы;
• кулачковые детали;
• цементуемые детали машин.

Russian Metals может поставлять круг 15Х, пруток 15Х, кованый круг, лист, плиту, полосу, трубу, проволоку и поковки по согласованным размерам.

Сталь 20Х

Сталь 20Х — конструкционная низколегированная хромистая цементуемая сталь. Она применяется для деталей, которым необходимы высокая твердость поверхности, износостойкость и прочная сердцевина.

Основные области применения 20Х:

• шестерни;
• зубчатые валы;
• втулки;
• пальцы;
• ролики;
• кулачки;
• поршневые пальцы;
• детали трансмиссии;
• цементуемые компоненты машин.

Russian Metals может поставлять круг 20Х, пруток 20Х, кованый круг, лист, плиту, полосу, бесшовную трубу, проволоку и поковки.