About Haimen City Mingzhu Steel Ball Co., Ltd.

Haimen City Mingzhu Steel Ball Co., Ltd. is a reliable and professional manufacturer specializing in the research, development and production of high-precision steel balls in China. Founded in 1992, the company is strategically located in Haimen, Jiangsu Province, enjoying superior geographical transportation conditions and convenient logistics support for domestic and foreign trade. The company’s production base covers a total area of 7,500 square meters, with standardized production workshops, independent inspection rooms and complete supporting facilities. At present, we are equipped with 105 sets of advanced professional processing and production equipment, forming a mature and efficient production line, with a stable annual production capacity of 2,500 tons. Adhering to standardized and standardized industrial production management, we have successfully obtained the authoritative IATF 16949: 2016 Quality Management System Certificate for the automotive industry, which fully proves that our product quality and production management have reached international advanced industry standards.
Our core product lineup mainly includes high-quality chrome steel balls and stainless steel balls, all of which are strictly manufactured in accordance with mainstream international standards such as ISO, DIN, JIS and AISI. Our products cover precision grades from G10 to G500, with a complete size range spanning from 2.0mm to 50mm, which can meet the conventional matching needs of most industrial scenarios. In addition to standard products, we also support personalized customized services for customers. We can tailor-make non-standard size steel balls and products with special material properties according to customers’ actual application requirements. Meanwhile, we provide a variety of precision mechanical processing services, including hole drilling, CNC precision machining and other deep processing technologies, to create customized supporting products for diverse industrial needs. Our high-performance steel ball products are widely and maturely applied in numerous fields such as precision bearings, automotive core components, ball screws,
linear slide rails, industrial pumps, spray equipment, and industrial grinding media, enjoying high recognition and good reputation among customers at home and abroad.
Since its establishment more than 30 years ago, our company has always adhered to the core business principle of quality first and integrity-based operation, always putting product quality control in the primary position of enterprise development. We have built a scientific, standardized and comprehensive enterprise management system, and have established a strict whole-process inspection and quality tracking system covering raw material procurement, production and processing, finished product testing to factory delivery. Every batch of raw materials will be sampled and inspected strictly before entering the production link. All finished steel ball products will undergo full automatic screening through professional roller bar sorting equipment and photoelectric surface defect detectors to eliminate defective products 100%. The rigorous whole-process quality control mechanism effectively ensures the high precision, high stability and high durability of our products, laying a solid foundation for long-term stable cooperation with global customers.
🎓
World-Class Team
Graduates from top universities worldwide
🔬
Advanced R&D
Self-developed
🤖
Innovation Focus
Multiple innovative technologies

Our Products

Custom steel ball

Custom steel ball

Model: Custom
Parameters: Custom

Stainless Steel Ball

Stainless Steel Ball

Model: Stainless Steel Ball
Parameters: Austenitic: Sizes 0.5 mm – 50.8 mm (0.020"–2.000"); ABMA precision G10–G1000; HRC 25–39 (annealed, soft); Ra fine; ISO 3290 / ABMA Std 10
Martensitic: Sizes 1.0 mm – 50.8 mm; G10–G100; HRC 50–55 (heat-treated); DIN 5401 / ISO 3290
Martensitic, high-carbon high-hardness stainless: Sizes 0.8 mm – 50.8 mm; G5–G100; HRC 58–65 (through-hardened); DIN 5401 / ABMA Std 10

Hastelloy Steel Ball

Hastelloy Steel Ball

Model: Hastelloy nickel-based superalloy (Ni–Cr–Mo–W)
Parameters: Per specification; typical 3 mm – 50 mm; oxidation and acid resistant

M50 Steel Ball

M50 Steel Ball

Model: High-speed molybdenum alloy tool steel
Parameters: Per aerospace specification; typical 3 mm – 50 mm; HRC 62–66; high hot hardness

Duplex Stainless Steel Ball

Duplex Stainless Steel Ball

Model: Duplex stainless steel
Parameters: Per specification; typical 10 mm – 100 mm; high strength and corrosion resistance

Hollow Steel Ball

Hollow Steel Ball

Model: Custom – seamless or welded (AISI 304 / 316 / carbon steel)
Parameters: Outside diameter and wall thickness per specification; through-holes available

Electroplated Steel Ball

Electroplated Steel Ball

Model: Custom – zinc / nickel / chrome plated (base: carbon or alloy steel)
Parameters: Base 1 mm – 50.8 mm; plating thickness per specification (e.g. zinc 5–25 µm)

Drilled Steel Ball

Drilled Steel Ball

Model: Custom – through-drilled or tapped (AISI 52100 / 304 / 440C)
Parameters: Drilled diameters and thread sizes per drawing; stock sizes 6 mm – 50.8 mm typical

Precision Steel Ball

Precision Steel Ball

Model: Precision Steel Ball
Parameters: 0.5 mm – 50.8 mm; Grade G3 / G5 / G10 / G16 / G25; sphericity within micro-inches

Non-Standard Steel Ball

Non-Standard Steel Ball

Model: Custom – per customer drawing / specification
Parameters: Sizes, tolerances, materials and features made to order (prototypes to production)

Machined Steel Ball

Machined Steel Ball

Model: Custom – per drawing (AISI 52100 / 1045 / 4140 optional)
Parameters: 10 mm – 200 mm+; ISO tolerance classes; roughness and hardness per specification

Carbon Steel Ball

Carbon Steel Ball

Model: Carbon Steel Ball
Parameters: 1 mm – 50.8 mm; Grade G100–G2000; low-carbon soft or HRC 55–60 when hardened

304 Stainless Steel Ball

304 Stainless Steel Ball

Model: 304 Stainless Steel Ball
Parameters: 1 mm – 50.8 mm; Grade G100–G1000; annealed soft; mirror polish available

316 Stainless Steel Ball

316 Stainless Steel Ball

Model: 316 Stainless Steel Ball
Parameters: 1 mm – 50.8 mm; Grade G100–G1000; annealed soft; excellent chloride resistance

440C Stainless Steel Ball

440C Stainless Steel Ball

Model: 440C Stainless Steel Ball
Parameters: 0.5 mm – 50.8 mm; Grade G10–G1000; HRC 58–62; max 0.07% P/S

420C Stainless Steel Ball

420C Stainless Steel Ball

Model: 420C Stainless Steel Ball
Parameters: 1 mm – 50.8 mm; Grade G25–G1000; HRC 50–55; corrosion resistant

Chrome Steel Ball

Chrome Steel Ball

Model: Chrome Steel Ball
Parameters: 1 mm – 50.8 mm; Grade G10–G1000; HRC 60–66; isotropic finish available

Bearing Steel Ball

Bearing Steel Ball

Model: Bearing Steel Ball
Parameters: 0.5 mm – 50.8 mm (1/64"–2"); Grade G10–G1000; HRC 60–66; Ra ≤ 0.05 µm

Company Gallery

Certifications & Awards

IATF16949:2016
IATF16949:2016

Success Stories & Case Studies

Biopharma & Specialty Chemical Equipment Maker

Biopharma & Specialty Chemical Equipment Maker

Met aggressive process chemistry requirements while maintaining hygienic integrity
Ultra-corrosion-resistant alloy; material certificate; clean-process compatible

Location: GLOBAL 📦 Quantity: 50,000 pcs
Chemical & Petrochemical Plant OEM

Chemical & Petrochemical Plant OEM

Exceptional resistance to strong acid and localized corrosion; minimal valve trim replacement
Hastelloy C-276 / N10276; EN 10204 3.1; MTR + PMI; extreme-corrosion documentation

Location: GLOBAL 📦 Quantity: 120,000 pcs/yr
High-Speed Spindle & Machine-Tool OEM

High-Speed Spindle & Machine-Tool OEM

Stable performance at high DN; extended spindle service interval
High-speed, high-temperature bearing grade; CMM + hardness verified

Location: GLOBAL 📦 Quantity: 40,000 pcs
Aerospace Engine Bearing Supplier

Aerospace Engine Bearing Supplier

Retained hardness & dimensional stability at elevated temperature; qualified for jet-engine use
Aerospace-grade M50; AMS 6490; high-temperature capability; full traceability

Location: GLOBAL 📦 Quantity: 60,000 pcs/yr
Desalination Plant EPC Contractor

Desalination Plant EPC Contractor

Outperformed 316 in aggressive chloride service; reduced replacement frequency
Engineered for high-chloride seawater; PREn >34; EN 10204 3.1 certificate

Location: GLOBAL 📦 Quantity: 90,000 pcs
Offshore Oil & Gas Operator

Offshore Oil & Gas Operator

PREn >34 resistance to chloride pitting/crevice corrosion; reliable in seawater
Duplex 2205; high PREn; NACE MR0175 awareness; MTR + PMI verified

Location: GLOBAL 📦 Quantity: 180,000 pcs
Marine & Floating Equipment OEM

Marine & Floating Equipment OEM

Controlled wall thickness & leak test ensured long-term buoyancy
Pressure/leak tested; corrosion-resistant coating options; made-to-print

Location: GLOBAL 📦 Quantity: 12,000 pcs
Architectural & Structural Fabricator

Architectural & Structural Fabricator

Lightweight yet structurally capable; enabled bold architectural geometries
Custom OD & wall thickness; welding-friendly; structural calculation support

Location: GLOBAL 📦 Quantity: 30,000 pcs
Consumer Electronics & Appliance Maker

Consumer Electronics & Appliance Maker

High-gloss, durable finish improved product aesthetics and corrosion life
Mirror-bright plating; RoHS-compliant plating options; custom color

Location: GLOBAL 📦 Quantity: 500,000 pcs
Automotive Trim & Hardware Supplier

Automotive Trim & Hardware Supplier

Uniform bright plating; passed customer salt-spray specification
Zinc/nickel/Chrome plating; salt-spray report; tight plating-thickness control

Location: GLOBAL 📦 Quantity: 3,000,000 pcs/yr
Oil & Gas Equipment Supplier

Oil & Gas Equipment Supplier

Withstood sour-service surface conditions; reliable sealing performance
Made-to-print; NACE-aware material options; pressure-test support

Location: GLOBAL 📦 Quantity: Project, 70 Kpcs
Specialty Valve & Hydraulic OEM

Specialty Valve & Hydraulic OEM

CNC-drilled hole position accuracy eliminated rework at customer assembly
CNC-drilled to drawing; hole position CMM-checked; custom threads

Location: GLOBAL 📦 Quantity: Project, 150 Kpcs
Optical & Metrology Instrument Maker

Optical & Metrology Instrument Maker

Exceptional sphericity & surface finish; directly usable as measurement reference
Ultra-high precision; mirror polishing available; calibration certificate option

Location: GLOBAL 📦 Quantity: Project, 90 Kpcs
Semiconductor Equipment OEM

Semiconductor Equipment OEM

Sub-micron roundness helped customer meet equipment accuracy targets
G3-G10 precision range; CMM & roundness metrology; class-1000 clean-pack optional

Location: GLOBAL 📦 Quantity: Annual, 200 Kpcs/yr
Aerospace MRO Provider

Aerospace MRO Provider

Reverse-engineered obsolete size; kept legacy aircraft platforms serviceable
Custom size + material matching; small-batch ODM; full traceability

Location: GLOBAL 📦 Quantity: Project, 25 Kpcs
Specialty Bearing & Instrument Maker

Specialty Bearing & Instrument Maker

Filled a size gap no catalog supplier could; enabled customer to finish a niche product line
Made-to-order non-standard sizes; low-volume friendly; MTR supplied

Location: GLOBAL 📦 Quantity: Project, 60 Kpcs
Robotics & Automation Integrator

Robotics & Automation Integrator

Drawing-based custom geometry; consistent roundness improved motion repeatability
Full ODM service; made-to-print; fast prototyping & small-batch support

Location: GLOBAL 📦 Quantity: Project, 40 Kpcs
Heavy Machinery OEM

Heavy Machinery OEM

Tight tolerance enabled direct assembly without secondary grinding
CNC-machined to drawing; custom diameters & materials; CMM inspection

Location: GLOBAL 📦 Quantity: Project, 80 Kpcs
Furniture & Hardware Manufacturer

Furniture & Hardware Manufacturer

Cost-competitive without sacrificing functional durability
Economical choice; zinc/plated options available; PPAP-style QC docs

Location: GLOBAL 📦 Quantity: Project, 1.5 Mpcs
General Industrial Distributor

General Industrial Distributor

Reliable, economical supply; helped distributor consolidate multiple SKUs from one source
Factory-direct; flexible packaging; fast stock shipment; low MOQ

Location: GLOBAL 📦 Quantity: Annual, 10 Mpcs/yr
Commercial Kitchen Equipment OEM

Commercial Kitchen Equipment OEM

Good corrosion & cleanability in humid, high-salt Gulf environment
Hygienic, easy-to-clean surface; material certificate available

Location: GLOBAL 📦 Quantity: Project, 300 Kpcs
Household & Sanitaryware Brand

Household & Sanitaryware Brand

Cost-effective corrosion-resistant solution with broad market acceptance
Most widely used stainless; RoHS; attractive bright finish; low MOQ

Location: GLOBAL 📦 Quantity: Annual, 2 Mpcs/yr
Pharmaceutical & Food Equipment Maker

Pharmaceutical & Food Equipment Maker

Met hygienic-design requirements; smooth finish facilitated cleaning validation
316L available for welding; 3A/EHEDG-aligned finish; MTR + EN 10204 3.1

Location: GLOBAL 📦 Quantity: Project, 400 Kpcs
Marine & Offshore Equipment OEM

Marine & Offshore Equipment OEM

Excellent seawater corrosion resistance; zero chloride-stress complaints
Marine-grade 316; low carbon option (316L) available; salt-spray test report

Location: GLOBAL 📦 Quantity: Annual, 1.5 Mpcs/yr
Aerospace Bearing Supplier

Aerospace Bearing Supplier

Met stringent corrosion + hardness specs; supported customer AS9100 qualification
AMS-aware process controls; 100% vision + hardness inspection; full traceability

Location: GLOBAL 📦 Quantity: Project + annual, 120 Kpcs
Medical Device Manufacturer

Medical Device Manufacturer

Withstood repeated autoclave cycles; high hardness and mirror-like finish extended instrument life
Premium martensitic stainless; AISI 440C with MTR; FDA-device-compatible documentation

Location: GLOBAL 📦 Quantity: Ongoing, 350 Kpcs/yr
Marine Hardware OEM

Marine Hardware OEM

Adequate corrosion performance at competitive cost; smooth surface finish
Cost-effective stainless option; salt-spray tested; RoHS-compliant

Location: GLOBAL 📦 Quantity: Project, 200 Kpcs
Valve & Pump Manufacturer

Valve & Pump Manufacturer

Good balance of hardness and corrosion resistance; lower total cost vs 440C for moderate-duty service
Martensitic stainless; hardenable to HRC 50-55; MTR + material certificate

Location: GLOBAL 📦 Quantity: Annual, 900 Kpcs/yr
Power-Tool OEM

Power-Tool OEM

Improved tool life under high-speed duty; zero field failures attributed to balls
High-hardness HRC 60-66; automated 100% visual sorting; fast 15-day shipment

Location: GLOBAL 📦 Quantity: Project batch, 600 Kpcs
Automotive Component Supplier

Automotive Component Supplier

Stable quality across shipments; customer reduced incoming inspection workload
Factory-direct OEM; bilingual (EN/ES) commercial & technical support; NAFTA/USMCA-friendly supply chain

Location: GLOBAL 📦 Quantity: Annual contract, 5 Mpcs/yr
Industrial Bearing OEM

Industrial Bearing OEM

Met tight roundness/roughness specs; helped customer qualify for a premium automotive Tier-2 program
DIN/ISO-compliant material; MTR + COA supplied; PPAP-style documentation support

Location: GLOBAL 📦 Quantity: Single project, 1.2 Mpcs
Tier-1 Bearing Manufacturer

Tier-1 Bearing Manufacturer

Reduced bearing noise & vibration; stable, on-time delivery enabled customer to shorten lead time and lower safety stock
ABMA G10 precision; 100% automated vision inspection; consistent HRC 60-66; direct-from-mill traceability

Location: GLOBAL 📦 Quantity: Ongoing annual supply, 8 Mpcs/yr

Company & Product Videos

Company Introduction & Factory Tour

⏱ Duration: 3:45 | 👁 Views: 15,230

Product Demonstration - Kestrel K-1

⏱ Duration: 5:12 | 👁 Views: 28,450

Technology Innovation Showcase

⏱ Duration: 4:30 | 👁 Views: 12,890

Customer Testimonials & Success Stories

⏱ Duration: 6:20 | 👁 Views: 9,650

Ready to Transform Your Life?

Contact us immediately to learn how our products meet your needs.