Ø 0.50mm – 150.00mm · EN-31 / AISI 52100, SS 316L, 440C, Tungsten Carbide, Inconel & Monel · ISO 3290 / DIN 5401 Certified · Supplying Mission-Critical OEMs Across 30+ Nations
Manufacturing Range
Every batch manufactured at Rama & Sons is calibrated to international metrological standards with 100% optical sorting, laser interferometry, and surface roughness profilometry.
Applications: High-speed miniature bearings, aerospace navigation gyros, surgical tools
Applications: Precision automotive bearings, electric vehicle motors, high-speed spindles
Applications: Automotive steering columns, hydraulic pumps, precision valves, ball screws
Applications: Industrial casters, conveyor bearings, locking mechanisms, agricultural machinery
Applications: Heavy-duty linear slides, bicycle hubs, furniture hardware, general valves
Applications: Mining grinding media, burnishing processes, vibratory polishing, ball transfer units
Applications: Agitator balls, paint mixing canisters, coarse crushing, check valves
| Precision Grade | Max Diameter Var. (VDws) | Sphericity (tw) | Roughness (Ra) | Hardness Range | Primary Engineering Applications |
|---|---|---|---|---|---|
Grade 10 (G10)High Demand | 0.25 µm | 0.25 µm | 0.020 µm | 60 – 66 HRC | High-speed miniature bearings, aerospace navigation gyros, surgical tools |
Grade 25 (G25)High Demand | 0.60 µm | 0.60 µm | 0.040 µm | 60 – 66 HRC | Precision automotive bearings, electric vehicle motors, high-speed spindles |
Grade 50 (G50) | 1.25 µm | 1.25 µm | 0.060 µm | 58 – 64 HRC | Automotive steering columns, hydraulic pumps, precision valves, ball screws |
Grade 100 (G100) | 2.50 µm | 2.50 µm | 0.100 µm | 55 – 62 HRC | Industrial casters, conveyor bearings, locking mechanisms, agricultural machinery |
Grade 200 (G200) | 5.00 µm | 5.00 µm | 0.150 µm | 50 – 60 HRC | Heavy-duty linear slides, bicycle hubs, furniture hardware, general valves |
Grade 500 (G500) | 12.50 µm | 12.50 µm | 0.200 µm | 45 – 55 HRC | Mining grinding media, burnishing processes, vibratory polishing, ball transfer units |
Grade 1000 (G1000) | 25.00 µm | 25.00 µm | 0.250 µm | 30 – 50 HRC | Agitator balls, paint mixing canisters, coarse crushing, check valves |
Every consignment is dispatched with EN 10204 3.1 Mill Test Certificates verifying exact metallurgical and dimensional tolerances.
Specialized diameter runs ranging from 0.50mm to 150mm engineered for unique valve, aerospace, and medical specifications.
Speak directly with our technical application & metallurgical engineering desk.
Engineered Excellence
From certified raw alloy wire to hermetically sealed export containers, explore how Rama & Sons guarantees zero-defect metallurgical integrity at every phase.
High-Velocity Forging
High-purity wire coil stock is precision-cut into slugs and formed into rough spherical blanks in closed dies at room temperature.
Deflashing & Equator Removal
Blanks run between concentric rill plates to machine away the equatorial seam and bring spherical geometry into tight preliminary tolerances.
Martensitic Quench & Temper
Balls enter continuous mesh-belt furnaces under controlled atmosphere, oil-quenched to produce high-strength martensite, then stress-relieved.
Sub-Micron Surface Finishing
Multi-stage abrasive lapping using specialized ceramic and diamond slurry compounds to refine sphericity and achieve mirror surface finishes.
Zero-Defect Metrology
Every single ball passes automated high-speed dual-camera optical scanners and eddy-current sensors to eliminate micro-cracks and form flaws.
Export Ready Preservation
Balls are washed with ultrasonic solvent cleaners, coated with premium rust-preventative synthetic oils, and sealed in multi-layer VCI barriers.
We customize carbon potential, cryogenic deep-freeze treatments, and passivation cycles for extreme service environments.
Metallurgical Science
Compare chemical compositions, hardness ratings, and environmental resistance properties to select the optimal precision alloy for your application.
DIN 1.3505 / JIS SUJ2
Key Engineering Characteristics:
Automotive wheel bearings, ball screws, linear guides, precision machine tool spindles.
View EN-31 ProductsC45 / BS 070M55
Key Engineering Characteristics:
Bicycle steering sets, castors, drawer slides, locking mechanisms, conveyor rollers.
View EN-9 ProductsWhy Partner With Us
With over two decades of metallurgical mastery, Rama & Sons delivers the reliability, technical documentation, and consistency demanded by Fortune 500 manufacturing supply chains.
Complete material traceability and test certificates for aerospace, automotive, and industrial applications. Every shipment includes certified optical roundness inspection, chemical spectro analysis, and hardness test reports.
From micro balls for medical devices to large grinding balls for industrial mills, we produce custom non-standard diameters (such as 4.789mm) with tight precision tolerances.
High-speed multi-axis optical cameras inspect 100% of bearing-grade balls for micro-cracks, flats, pits, and soft spots, guaranteeing zero field failures for our global OEM partners.
With maritime VCI packaging, full customs compliance documentation, and prompt air/sea freight dispatch from our advanced manufacturing works, we power supply chains across North America, Europe, Asia, and the Middle East.
Global Reach
Providing precision metallurgical components for critical applications across 30+ nations.
Select your required alloy grade, nominal diameter, and precision class to pre-configure an official Commercial Request for Quotation (RFQ).
EN-31 Chrome Steel (AISI 52100) · 10.00 mm (25/64") · Grade 10 (G10 - ±0.00025mm) · 10,000 to 50,000 pcs (Standard Batch)
Verified Industry Reviews
High-precision metallurgical components powering critical automotive, bearing, valve, and aerospace assemblies worldwide.
"We have been sourcing EN-31 bearing steel balls from Rama & Sons for our precision bearing manufacturing lines. Their dimensional consistency and strict ISO 3290 Grade 10 compliance have been exceptional across multi-ton orders."
Priya Sharma
Head of Procurement
Bharat Heavy Electricals Limited (BHEL)
"The AISI 316 and 440C stainless steel balls from Rama & Sons deliver outstanding performance in our chemical processing and corrosive flow equipment. Certified EN 10204 3.1 test reports with complete heat traceability give us full confidence."
Rohan Mehta
Chief Metallurgical Engineer
Tata Steel Downstream Products Ltd.
"Their stainless steel cut wire shots and precision polishing media have significantly enhanced our surface finishing processes. Consistent hardness, uniform size, and zero contamination."
Anjali Desai
Operations Director
Titan Company Limited (Precision Division)
"Rama & Sons has been our primary supplier for custom precision gauges and specialty alloy balls for over five years. Their engineering support, custom diameter capabilities, and fast delivery are first-rate."
Vikram Singh
General Manager (Heavy Engineering)
Larsen & Toubro (L&T)
"The roundness and mirror surface finish (Ra ≤ 0.02µm) of bearing balls from Rama & Sons have allowed us to maintain zero-defect quality and minimize assembly rejection rates. Truly a world-class precision manufacturer."
Deepak Kumar
Quality Assurance Lead
SKF India Ltd.
"For our high-pressure check valves and severe-service fluid equipment, we rely on Rama & Sons for Tungsten Carbide, Inconel 625, and alloy balls. Their technical responsiveness and tight tolerances are exceptional."
Sneha Patel
Lead Design Engineer
Flowserve India Controls Pvt. Ltd.
Critical specifications, certification requirements, and export logistics details for engineering and procurement teams.
Steel ball grades define how round and precise a ball is. Grade 10 (G10) is our highest precision grade — with diameter variance under 0.25 microns and a mirror finish (Ra 0.020µm), used in high-speed electric motors and aerospace bearings. Grade 25 (G25) is standard for precision automotive bearings and ball screws. Grade 100 (G100) is used for conveyor rollers, casters, and standard rotating parts.
Yes — 100% of commercial orders from Rama & Sons include an official EN 10204 3.1 Inspection Certificate. This includes chemical spectro analysis (Carbon, Chrome, Nickel, Molybdenum, etc.), Rockwell hardness (HRC), size and roundness inspection data, and raw material heat batch numbers for complete traceability.
Yes! Unlike large commodity mills that require multi-ton orders of standard sizes, we manufacture custom metric diameters (0.50mm to 150.00mm) down to exact decimal microns (for example: 4.789mm, 6.312mm). We supply small prototype quantities (10 to 50 pieces) and production volumes in Inconel 625, Monel K-500, Stellite, Hastelloy, and Tungsten Carbide with EN 10204 3.1 test certificates.
For standard catalog sizes in EN-31, SS 304, and SS 316, our MOQ is just 1 kg with 3 to 5 business day dispatch from ready stock. For custom sizes or exotic superalloys (Inconel, Monel, Tungsten Carbide), we can provide small prototype batches (such as 10 to 50 pieces) or full production volumes.
All steel balls go through ultrasonic cleaning and are coated with rust-preventive oil. They are vacuum-sealed inside heavy-duty rust-proof VCI bags, packed in strong export cartons with moisture absorbers, and strapped onto export pallets — certified for 24+ months rust protection at sea.
We support all standard shipping terms: FOB, CIF, CFR, and DDP. Payment options include Letter of Credit (L/C at sight), Wire Transfer (T/T), and credit terms for regular OEM customers. We can issue invoices in USD, EUR, GBP, or AED.
