[ Ball Bearing ]
[ Ball Bearing ]
Stainless steel ball bearings offer a critical balance between mechanical strength and corrosion resistance. Photo: Dreamstime.
AISI 440C contains high carbon and chromium levels, enabling it to be heat treated to very high hardness levels, typically up to ~ 60 HRC under conventional through-hardening conditions. This makes it particularly suitable for bearing races and rolling elements requiring high loadcarrying capacity and resistance to rolling contact fatigue. While 440C provides lower corrosion resistance than austenitic grades such as
304 or 316, it significantly outperforms standard bearing steel( AISI 52100) in corrosive environments. Its excellent grindability and ability to achieve a fine, polished surface further support its use in precision bearing applications.
Manufacturing 440C bearing steel The production of AISI 440C bearing steel begins with controlled melting in an electric arc furnace( EAF), followed
by secondary refining in ladle refining furnaces( LRF) and vacuum degassing( VD) to achieve tight chemical composition control and low inclusion content. In modern production routes, the steel is typically continuously cast into billets or blooms. Continuous casting offers improved yield, productivity, and consistency compared to ingot casting. Process parameters such as casting speed, temperature control, electromagnetic stirring, and secondary cooling are carefully optimised to minimise segregation, surface cracking, and centreline porosity. These measures are critical for ensuring uniform microstructure and reliable performance after subsequent heat treatment.
Major ball bearing components The functionality of rolling-element bearings relies on the interaction of four primary components:
• Inner ring( race): Mounted on the rotating shaft, providing a hardened raceway for the rolling elements
• Outer ring( race): Installed in the stationary housing, forming the opposing raceway
• Rolling elements: Balls or rollers that carry the load and enable rolling motion
Manufacturers of Special Steels & Alloys
World leading producers of high-quality steels, stainless, nickel, cobalt and titanium alloys
Pro-Roll is your one-stop shop for everything from large ingots to custom bar rolling, with full melt-to-finish supply or expert hirework conversion.
Small Quantity Melts to Bespoke Chemistries
In-house facilities include:
• 2 x 5-tonne Induction Melting Furnaces( Ingot sizes of 1, 5 and 10 tonnes)
• 1000-Tonne Open Die Forging Press
• GFM SX-16 Rotary Precision Forge
• 10” Hand Rolling Mill •Bar Sawing
• NADCAP Heat Treatment Facility, with water quenching and rapid air cooling
• Reeling, Stretch and Bump / Press Straightening
•Centreless Grinding •Machining( Lathe Turning and Milling)
• Non-Destructive Testing( UST, DPI and MPI)
Hirework & Full Supply Options
Existing Bar Stock Conversion
pro-roll. co. uk Pluto Works, Penistone Road North, Sheffield, S6 1LP, UK | + 44( 0) 114 232 4242 | contact @ pro-roll. co. uk