Product Overview

AISI 440C Stainless Steel Balls are martensitic hardened stainless steel balls designed for precision devices that demand exceptional hardness, outstanding wear resistance, fine surface finishing, and tight dimensional tolerances. Engineered and tested across thousands of installations and long-running export supply programs, 440C balls are a go-to choice for anti-friction motion and repeated contact applications where component stability directly influences service life.

This product is widely used in precision bearings and anti-friction bearings, conveyor belts and rollers, special valves, couplings, and ballpoint pens. It is also selected across food-related equipment, medical equipment parts, knotting applications, and oil refining environments where high hardness is essential and corrosion exposure is within the material’s capability range.

SDBALLS supplies AISI 440C stainless steel balls with strict process control, flexible OEM and ODM customization, and ontime delivery planning. With more than 30 years of production experience, two factories, modern production equipment, and an export-only business serving more than 50 countries, SDBALLS supports global manufacturers and distributors with consistent quality and dependable supply.

Key Features & Specifications

AISI 440C stainless steel balls deliver hardened martensitic performance with excellent wear resistance and stable precision, supported by clear size range, grade options, and corrosion behavior.

Physical Property

Item	Value
Corrosion Resistant	Fair
Wear Resistant	Excellent
Magnetism	Yes

Technical Data

Property	Value
Hardness	HRC 57 – 65
Density	7.70g/m3
Young’s Modulus	210GPa
Tensile Strength	1900-2000Mpa

Chemical Composition

Type	%C	%Si	%Mn	%P	%S	%Cr	%Mo
440C	0.95-1.20	1.00 max	1.00 max	0.040 max	0.030 max	16.00-18.00	0.75 max

International Standard

USA	CHN	GER	FRA	ITA	UK	RUS	JAP
440C	9Cr18Mo	1.4125	Z100CD17	X 105CrMo17	–	95X18	SUS440C

Product Images And What They Show

• Product gallery images showing finished AISI 440C stainless steel balls with a consistent metallic surface appearance suitable for precision rolling and seating roles.
• Page imagery supporting specification-driven quotation and B2B inquiry workflows for OEM, distributor, and project procurement.
• Brand and manufacturing visuals reflecting SDBALLS large-scale, export-oriented production capability.

Key Benefits & Competitive Advantages

• High hardness of HRC 57 to 65 supports long wear life in bearings, rollers, and valve seating elements.
• Excellent wear resistance supports reduced maintenance frequency and longer component service cycles in repeated-contact applications.
• Precision grade options from G20 through G1000 support engineering fit for both higher precision assemblies and cost-optimized functional components.
• Diameter range from 0.5mm to 150.00mm supports standardized sourcing for miniature mechanisms through larger industrial assemblies.
• Clear corrosion behavior guidance supports correct application selection in fresh water, steam, oil, gasoline, and alcohol exposure.
• Defined limitations for seawater pitting and poor acidic-environment resistance help reduce field failures caused by misapplication.
• Magnetic property supports automated handling, sorting, and assembly feeding in many manufacturing lines.
• OEM and ODM flexibility supports custom specifications and stable supply agreements for global customers.

Application Scenarios & Use Cases

Scenario	Industry	Key Benefit	Why This Product
Precision bearing rolling elements	Bearings and motion systems	Wear life and dimensional stability	Martensitic hardened structure and tight tolerances support precision bearing performance
Anti-friction bearing components	Industrial machinery	Reduced friction wear	Excellent wear resistance supports long-term anti-friction operation
Conveyor belt rollers and roller assemblies	Material handling	Durability under repetitive contact	High hardness supports roller systems exposed to repeated rolling and contact stress
Special valve check and seating elements	Valves and fluid control	Stable seating and wear resistance	High hardness supports repeated sealing contact and improved wear performance
Quick couplings and coupling mechanisms	Connectors and fittings	Consistent engagement performance	Stable ball geometry supports predictable coupling behavior
Ballpoint pen mechanism balls	Stationery and consumer precision parts	Smooth rolling and longer life	Fine surface finishing and hardness support consistent writing performance
Food-related equipment components	Food and processing equipment	Wear resistance with defined corrosion capability	Used for food applications where wear is critical and media exposure aligns with specified corrosion behavior
Medical equipment parts	Medical equipment	Precision and consistency	Used in medical equipment parts where repeatable rolling function is required

Competitive Comparison

Feature/Aspect	This Product	Typical Alternative
Material type	Martensitic hardened stainless ✓	Austenitic stainless grades focused on corrosion over hardness
Hardness range	HRC 57 to 65 ✓	Lower hardness options ✗
Wear resistance	Excellent ✓	Good to fair depending on material ✗
Dimensional tolerances for precision devices	Designed for tight tolerances ✓	Less consistent for precision use ✗
Corrosion performance in common media	Resists fresh water, steam, oil, gasoline, alcohol ✓	Varies and often not clearly defined
Seawater exposure suitability	Prone to pitting in seawater ✗	Higher-corrosion grades can be better ✓
Acidic environment suitability	Poor in acidic environment ✗	Alternative alloys may be selected based on chemistry ✓
Magnetism	Yes ✓	Often slight or no magnetism in austenitic grades ✗
Grade selection range	G20 to G1000 ✓	Fewer grade options ✗
Industry breadth	Bearings, valves, rollers, couplings, pens, food, medical, oil refining ✓	More limited application positioning ✗

Technology & Design Highlights

AISI 440C stainless steel balls are built around a hardened martensitic structure that supports high hardness, superior wear resistance, and stable precision across production lots.

Hardened Martensitic Performance For High-Wear Assemblies

This product is specified at HRC 57 to 65, enabling strong resistance to surface wear and contact deformation. This makes it highly suitable for precision bearings, anti-friction bearings, conveyor rollers, and valve seating components where repeated cycles demand stable geometry and surface behavior.

Surface Finishing And Tolerance Discipline For Precision Devices

The product positioning emphasizes remarkable surface finishing and dimensional tolerances, supporting precision devices where ball roundness and surface condition affect friction, noise, and component life. Precision grades from G20 through G1000 allow engineering teams to select the correct tolerance level for each assembly.

Corrosion Behavior Boundaries For Accurate Specification

The corrosion resistance guidance provides practical selection rules. The material is described to resist corrosion when exposed to fresh water, steam, oil, gasoline, and alcohol, while being prone to pitting in seawater and having poor corrosion resistance in acidic environments. These boundaries enable correct matching to real operating fluids and reduce the risk of premature corrosion failure.

Production Capability Supporting Stable Supply

SDBALLS manufacturing includes raw material and wire drawing, cold forging, flashing, heat treating when required, descaling, hard grinding, lapping, polishing and finishing, and inspecting. This controlled process flow supports consistent hardness, surface quality, and dimensional repeatability at scale.

Industry Compliance & Quality Assurance

Quality assurance and process control are essential for hardened stainless steel balls used in precision and safety-relevant assemblies.

Certified Quality Management

SDBALLS is an ISO9002:2000 certified company with strict quality control throughout every manufacturing stage. This supports consistent production control, inspection discipline, and dependable output for international customer requirements.

Scalable Manufacturing And Export Reliability

SDBALLS operates two factories covering 8,000 square meters with more than 200 sets of modern and efficient production equipment and annual steel ball production of more than 5,000 tons. Products are 100% exported and sold in more than 50 countries, supporting OEM programs and distributor replenishment with stable capacity and predictable delivery planning.

OEM And ODM Support

OEM and ODM capability supports customization for diameter, grade selection, and specification alignment. Efficient planning supports ontime delivery and reliable shipment execution for global customers.

Global Reach & Target Markets

SDBALLS is an export-oriented steel ball manufacturer with more than 30 years of production experience and extensive successful case experience across global industries. With products sold in more than 50 countries and a strong track record supporting international customers, SDBALLS helps buyers meet local procurement expectations through clear specifications, international standard equivalency mapping, and consistent quality backed by ISO9002:2000 certification.

Target Markets And Localization Fit

Target Region	Customer Types	Industry Focus	Our Advantage
North America	OEM manufacturers, bearing and motion system companies, industrial distributors, engineering firms	Precision bearings, anti-friction assemblies, valves and couplings	Program-ready grades and specs, export-only supply experience, ISO9002:2000 quality management
Europe	Precision equipment manufacturers, component integrators, wholesalers, industrial service providers	Precision devices, conveyor rollers, medical equipment parts	Strong documentation and international standard mapping for material equivalency and engineering alignment
Middle East	Project procurement teams, oil and refining-related equipment suppliers, industrial distributors	Oil refining devices, fluid control components, industrial machinery	Proven experience supporting industrial applications and stable export logistics for project timelines
Southeast Asia	OEM assembly plants, trading companies, consumer hardware manufacturers	Couplings, rollers, ballpoint pen mechanisms, general precision components	Broad size range and flexible OEM and ODM support for fast product-line scaling
South America	Distributors, MRO suppliers, manufacturers	Bearings, valves, industrial replacement parts	Stable manufacturing capacity and ontime delivery planning for repeat replenishment programs

Customer Success & Experience

Based on decades of manufacturing expertise and an export-only business model, SDBALLS has extensive hands-on experience supplying hardened stainless steel balls for precision devices and industrial assemblies worldwide. Engineered and tested across thousands of installations, AISI 440C stainless steel balls are frequently selected by customers who require high hardness, excellent wear resistance, and consistent dimensional tolerances for long service life.

Typical successful programs include a precision bearing manufacturer supporting anti-friction assemblies where wear control and stable ball geometry reduce friction-related failure, an industrial conveyor equipment integrator using balls within roller and movement mechanisms where surface finishing and hardness improve durability, and an oil refining equipment supply chain requiring hardened balls for components exposed to oils and related operating media within the specified corrosion limits.

SDBALLS supports customers through specification confirmation, grade selection, OEM and ODM customization, and responsive technical service. Many buyers progress from qualification to repeat orders across multiple diameters and grades, reflecting dependable quality control, scalable capacity, and reliable export delivery performance.

FAQ

Q: What is the material for this product?

A: The product is presented as AISI 440C stainless steel balls, and the page lists the material line as AISI 420C. The chemical composition table provided is for type 440C, and the international standard table is also for 440C.

Q: What sizes can be supplied?

A: The diameter range listed is 0.5mm to 150.00mm. This supports both miniature precision components and larger industrial assemblies within the stated range.

Q: What precision grades are available for AISI 440C stainless steel balls?

A: Precision grades listed are G20, G40, G80, G100, G200, G500, and G1000. This allows selection based on tolerance needs and cost targets.

Q: What hardness range does this product provide?

A: The hardness listed is HRC 57 to 65. This high hardness supports excellent wear resistance for bearings, rollers, and valve seating applications.

Q: What are the typical applications for these stainless steel balls?

A: Applications listed include precision bearings, anti-friction bearings, conveyor belts and rollers, special valves, couplings, and ballpoint pens. They are also used in food-related applications, medical equipment parts, knotting applications, and oil refining.

Q: How does corrosion resistance perform in common media?

A: The corrosion resistance statement indicates the material can resist corrosion when exposed to fresh water, steam, oil, gasoline, and alcohol. The statement also notes pitting in seawater and poor corrosion resistance in acidic environments.

Q: Are these balls magnetic?

A: Yes, magnetism is listed as yes in the physical property section. This can support automated handling and sorting in many production environments.

Q: Can SDBALLS support OEM customization and global supply programs?

A: Yes, SDBALLS provides OEM and ODM support, strict process control, and ontime delivery planning. The company has more than 30 years of experience, operates two factories with modern equipment, produces more than 5,000 tons annually, and exports to more than 50 countries.