SKF steel and heat treatment solutions

Oct 12, 2026

Uploaded by Himbo

SKF steel and heat treatment solutions brochure providing an overview of common bearing steel grades and the corresponding heat-treatment routes. It explains why the long-established classic 1% carbon, 1.5% chromium bearing steel (Grade 3) remains widely used, then outlines when enhanced properties are needed. The brochure organizes content into equivalent steel tables, hardening-process characteristics, typical application conditions (fatigue, corrosion, elevated temperature), and steel-grade/heat-treatment combination examples with relative performance radar plots.

LanguageEnglish

CategoryGeneral

FormatPDF

Pages32

Reading Time11 min

AccessFree to download

Contents

Table of equivalent steel compositions

Hardening heat treatments

Subsurface fatigue

Surface fatigue

Structural fatigue

Corrosion

Elevated temperatures

Premature bearing failure

Sustainability

Solutions

Through-hardening bearing steels

Surface hardening bearing steels

Secondary hardened steels

SKF steel and heat treatment solutions 2 Contents SKF steel and heat treatment solutions 4 Table of equivalent steel compositions 5 Hardening heat treatments 6 Subsurface fatigue 7 Surface fatigue 8 Structural fatigue 9 Corrosion 10 Elevated temperatures 11 Premature bearing failure 12 Sustainability 13 Solutions 14 Through-hardening bearing steels 14 Martensite SN 14 Martensite S0/S1 15 Bainite 16 Bainite Grade 7P 17 Grade 3M 18 Carbonitrided 19 Surface hardening bearing steels 20 Carburised 20 Case carbonitrided 21 Surface induction hardened 22 Carbon steels 22 Alloyed steels 23 Stainless bearing steels 24 Stainless steels 24 High nitrogen stainless steels 25 Secondary hardened steels 26 M50 26 M50NiL 27 32CDV13 (AMS 6481) 28 PM M62 29 SKF steel and heat treatment solutions This brochure gives an overview of the most common steel and heat treatment solutions used by SKF The purpose of this brochure is to illustrate the particular strengths of each solution and to indicate the likely application conditions where they could be used The classic 1% carbon 1,5% chromium bearing steel, called Grade 3 by SKF, has existed for over 100 years The reason for its longevity is due to the attractive combination of availability, ease of manufacture and good bearing performance in conditions involving rolling contact fatigue Despite this, for certain application conditions, there is a need for improved properties These improvements can be achieved by altering the heat treatment process for the Grade 3 steel or by employing alternative steel and heat treatment combinations As a result, SKF has a broad portfolio of steel and heat treatment solutions which are described in this brochure Note that advice from materials experts must besought when selecting solutions as there are additional factors related to economics, geography and supply logistics which are not covered in this overview The first section is a table showing the common names used for some SKF steel grades and the equivalent steel designations The second section gives a brief description of the characteristics of the hardening heat treatment processes most commonly used by SKF The third section focuses on the most commonly encountered application conditions and illustrates that there is more than one potential steel and heat treatment solution for each condition The fourth section describes the steel and heat treatment combinations For each combination, a specific steel grade is given as an example However, this does not exclude other steel grades from being used For each solution, a radar plot shows the relative performance, as indicated in the example below • Sub-surface initiated fatigue – High load, full film lubrication • Surface initiated fatigue – Thin film lubrication – Particle contaminated lubrication • Structural fatigue – High interference fits – Bending due to flexible housings • Corrosion • Elevated temperature Subsurface Variant 1 Variant 2 Temperature Surface Corrosion Structural A specific steel grade will be used for the actual radar plots Table of equivalent steel compositions SKF designation Comparable steel designation (composition) Common SKF name(s) Through hardening steels Grade 3 Grade 24 Grade 4 Grade 5 Grade 6 Grade 7 Surface hardening steels Grade 152 Grade 157 Grade 159 Grade 236 Grade 170 Grade 255 Grade 55LS Grade 70LS Grade 50 Stainless steels Grade 307 Grade 306 Secondary hardening steels Grade 400 Grade 401 Powder metallurgy steels Grade PM62 100Cr6, 52100, SUJ2, GCr15, 1 3505 100CrMo7, 1 3537 100CrMnSi6-4, 1 3520 100CrMo7-3, 1 3536 100CrMo7-4, 1 3538 100CrMnMoSi8-4-6, 1 3539 20MnNiCrMo3-2, 8620H, 1 6522 20NiCrMo7, 4320H, 1 3576 18CrNiMo7-6, 1 6587 19MnCr5 8219 18NiCrMo14-6, 1 3533 C56E2, 1055/1060, 1 1219 70Mn4, 1070M, 1 1244 4147/4147H/4150/4150H, 1 7228

FAQs

What does the brochure cover about SKF steels and heat treatments?

It provides an overview of common steel grades and hardening heat-treatment solutions used by SKF, linking each solution to strengths and likely application conditions.

How are hardening heat treatments grouped in the brochure?

They are divided into through hardening and surface hardening. Through hardening produces homogeneous microstructures across the component, while surface hardening creates a hardness profile from surface to core.

Why is the SKF Grade 3 bearing steel commonly used, and when is improvement needed?

Grade 3 is valued for availability, ease of manufacture, and good bearing performance under rolling contact fatigue. For certain application conditions, improved properties can be achieved by adjusting heat treatment or using alternative steel/heat-treatment combinations.

Oct 12, 2026

Uploaded by Himbo