Description
Stainless Steel 316 Machining – CNC Machining of SS 316 & 316L Components
Price: US$ 11.50 / kg | Ex-Works India | MOQ: 50 kg | Lead Time: 15–25 working days
Stainless Steel Fittings India specialises in comprehensive CNC machining of SS 316 and SS 316L stainless steel — the most widely used molybdenum-bearing austenitic grade in industrial, offshore, chemical, power, and electrical engineering. Our SS 316 CNC machining services encompass turning, milling, drilling, boring, reaming, broaching, thread cutting, thread milling, grinding, and multi-operation machining centre work. Machined SS 316 components include precision turned parts, milled blocks, bored housings, threaded adapters, precision flanges, valve bodies, pump shafts, manifold blocks, and custom structural components. We supply electrical OEMs, EPC contractors, power utilities, and industrial distributors in USA, UK, Germany, UAE, Singapore, Australia, Netherlands, Canada, and South Africa.
Detailed Product Overview
CNC Turning of SS 316 – Turned Parts, Shafts, Bushings and Adapters
CNC turning of SS 316 and SS 316L on 2-axis and multi-axis CNC lathes produces precision turned components including shafts, bushings, adapters, nipples, couplings, spacers, and custom turned bodies. SS 316 has lower machinability than SS 303 due to its higher work-hardening rate; however, correct cutting parameters (cutting speed 100–130 m/min, carbide insert grade IC907 or equivalent, high coolant pressure) enable economical turning. Diameter tolerances of ±0.01 mm (IT6) are routinely achieved. Related terms: CNC turning SS 316, SS 316L turned shaft, stainless 316 bushing machined, turned adapter SS316, precision turned SS316L nipple.
CNC Milling of SS 316 – Flat Parts, Blocks, Manifolds and Profiles
CNC milling operations on SS 316 and SS 316L include face milling, slot milling, pocket milling, contour milling, thread milling, and 3D profile milling. SS 316 milling requires climb milling strategy, sharp coated carbide end mills (TiAlN or AlCrN coating), and through-spindle coolant. Milled SS 316 components include manifold bodies, equipment bases, valve body profiles, mounting pads, and custom profiled flanges. Surface finish Ra 0.8–3.2 μm standard; Ra 0.4 μm achievable on finishing passes. Related terms: CNC milling 316 stainless, SS 316L milled block, stainless 316 machined manifold, milled SS316 flange, face milling SS 316L.
CNC Drilling, Boring and Reaming of SS 316 Components
Precision drilling, boring, and reaming of SS 316 components is performed on CNC machining centres with carbide-tipped drills and boring bars. Hole diameter tolerances of H7 (±0.012 mm for 20 mm bore) are achieved through bore-turn-ream sequences. Deep-hole drilling (L/D up to 20:1) in SS 316 uses gun drilling with through-coolant. Precision bored SS 316 components include valve bodies, hydraulic cylinder liners, pump housings, and precision bearing bores. Related terms: CNC boring SS 316, stainless 316 reamed bore, gun drilling SS316L, precision bore stainless 316, H7 bore SS316 component.
Threading Operations on SS 316 – Tapping, Thread Milling and Thread Rolling
Internal and external threads in SS 316 are produced by CNC thread milling (preferred for accurate pitch and minimal torn thread risk), tapping with spiral-flute taps in through-holes, and thread rolling for external threads requiring cold-worked root strength. Thread standards produced: ISO metric (M3–M100), UNC, UNF, BSP, BSPT, NPT, NPTF, ACME, and Stub ACME. All threads gauged with certified plug/ring gauges per ISO 1502. Related terms: thread milling SS 316, tapping stainless 316, thread rolling SS316 shaft, BSP thread SS316 component, ISO metric thread stainless 316L.
Multi-Axis CNC Machining of Complex SS 316 Components
4-axis and 5-axis CNC machining centres machine complex SS 316 components in a single setup: angled ports, compound undercuts, complex curved profiles, and multiple face features. 5-axis simultaneous machining eliminates multiple setups and associated datum transfer errors, achieving overall positional accuracies of ±0.02 mm on complex parts. Applications include multi-port manifold blocks, impeller blades, complex valve bodies, and aerospace-grade SS 316L structural fittings. Related terms: 5-axis SS316 machining, multi-axis CNC stainless 316, complex SS316L component, simultaneous 5-axis stainless, compound angle CNC machining SS316.
Grinding and Precision Finishing of SS 316 Parts
Cylindrical grinding, surface grinding, and centreless grinding of SS 316 components achieve diameter tolerances of ±0.002 mm (IT4/IT5) and surface finishes Ra 0.1–0.4 μm. Ground SS 316 parts include precision valve spools, gauge stems, pump plungers, shaft journals, and bearing seats where turning alone cannot achieve the required finish and tolerance. OD grinding range: 3 mm to 300 mm diameter. Related terms: cylindrical grinding SS 316, surface grinding stainless 316L, centreless grinding SS316, precision ground stainless shaft, grinding SS316L valve spool.
EDM (Electrical Discharge Machining) of SS 316
Wire EDM and sinker EDM of SS 316 produce precise slots, profiles, keyways, punch profiles, and complex internal geometries not achievable by conventional machining. Wire EDM achieves dimensional accuracy of ±0.005 mm and surface finish Ra 0.4–0.8 μm. Applications include die components, precision gauging fixtures, thin-wall slots, and small internal profiles in SS 316 blocks. Related terms: wire EDM stainless 316, EDM machining SS316L, electrical discharge machining stainless, wire cut SS316, spark erosion stainless steel.
Turnkey CNC Machining of SS 316 Assemblies
Stainless Steel Fittings India provides turnkey machining of SS 316 sub-assemblies: multiple components machined, inspected, and assembled to a sub-assembly drawing. Press-fit bushings, threaded inserts, staked fasteners, and welded sub-assemblies are within our scope. Turnkey assembly reduces the customer’s supply chain to a single source and a single point of quality responsibility. Related terms: SS316 machined assembly, turnkey stainless machining, sub-assembly CNC SS316, stainless 316 machined sub-assembly, complete machined package SS316.
Key Features of SS 316 CNC Machining
- Comprehensive machining: turning, milling, drilling, boring, grinding, threading, EDM
- Tolerances to IT5/IT6; grinding to IT4; CMM-verified
- Multi-axis (4-axis, 5-axis) machining centres for complex single-setup parts
- Material: SS 316, SS 316L, SS 316Ti, SS 316H — all with EN 10204 3.1 MTC
- Price: US$ 11.50 / kg ex-works India
- In-house passivation, electropolishing, and surface treatment
- 100% hydrostatic / pneumatic pressure testing for pressure-containing parts
- Full documentation: MTC, dimensional report, surface roughness, hardness, passivation cert.
Machinability of SS 316 – Technical Considerations
SS 316 has a machinability rating of approximately 45–50% relative to free-machining brass (AISI 12L14 = 100%). Its high work-hardening rate demands positive cutting geometry, sharp tooling, and adequate chip clearance. Recommended cutting speed for turning SS 316 is 100–140 m/min with carbide inserts (ISO grade M20–M25); for milling, 80–120 m/min with coated carbide end mills. High coolant pressure (50–70 bar through-spindle) prevents work-hardening on re-entry passes. Our machining team optimises cutting data for each SS 316 grade and component geometry to maximise tool life and surface quality.
Comparison: SS 316 vs. SS 316L vs. SS 316Ti for Machining
| Property | SS 316 | SS 316L | SS 316Ti |
|---|---|---|---|
| Carbon Content (max %) | 0.08 | 0.03 | 0.08 |
| Molybdenum (%) | 2.0–3.0 | 2.0–3.0 | 2.0–2.5 |
| Titanium | Nil | Nil | 5×C min |
| Sensitisation Risk (welding) | Moderate | Low | Very Low |
| Machinability | Moderate | Moderate | Slightly Lower |
| Max Service Temperature | 870°C (intermittent) | 870°C (intermittent) | 900°C (continuous) |
| EN Grade | 1.4401 | 1.4404 | 1.4571 |
Heat Treatment and Condition of Machined SS 316 Parts
SS 316 machined components are supplied in the solution-annealed condition (1020–1100°C, rapid quench) unless otherwise specified. This condition provides minimum hardness (~200 HB) and maximum corrosion resistance. Stress-relieving after machining (450–550°C in inert atmosphere) is available for thin-wall or residual stress-sensitive applications. Cold-worked (1/4 hard, 1/2 hard) SS 316 bar stock is available for applications requiring higher tensile strength without heat treatment.
Surface Treatment of CNC Machined SS 316 Parts
Post-machining surface treatments include: chemical passivation (citric acid or nitric acid per ASTM A967 / AMS 2700), electropolishing (Ra <0.4 μm, mirror finish), glass bead blasting (satin Ra 0.8–1.6 μm), pickling and passivation (mixed HF/HNO3 acid), electrolytic polishing, and PVD coating (TiN, TiAlN for wear-resistant applications). Each treatment is specified at order stage and is documented with a process certificate.
Particle Cleanliness and Flushing for Precision SS 316 Parts
For hydraulic, pneumatic, and instrument-grade SS 316 machined parts, internal passage cleanliness is critical. We offer ultrasonic cleaning, high-pressure flushing, and particle count testing per ISO 23309 (NAS 1638 / ISO 4406). Clean-room packaging in Class 100 bags for particle-sensitive instrument applications is available. Particle cleanliness certification is provided as part of the quality documentation package.
Technical Specifications
| Parameter | Specification |
|---|---|
| Primary Grade | SS 316 (1.4401 / S31600); SS 316L (1.4404 / S31603) |
| Machining Processes | CNC Turning, Milling, Drilling, Boring, Reaming, Grinding, EDM, Thread Milling |
| Tolerance | IT6 (±0.01 mm) standard; IT4 (±0.002 mm) by grinding |
| Max Part Size | Turning: Ø500 mm × 1500 mm; Milling: 600 × 400 × 300 mm; Grinding: Ø300 mm |
| Surface Finish | Ra 0.4–3.2 μm machined; Ra <0.2 μm electropolished |
| Thread Standards | ISO Metric, UNC, UNF, BSP, BSPT, NPT, NPTF, ACME, Stub ACME |
| Operating Temp. | -196°C to +870°C (SS 316); -196°C to +870°C (SS 316L) |
| MTC Standard | EN 10204 3.1 / 3.2 |
| Price | US$ 11.50 / kg (ex-works India) |
| Lead Time | 15–25 working days standard; 7–10 days express |
| MOQ | 50 kg or 10 pcs (whichever is lower) |
SS 316 Grade International Equivalents
| Grade Name | UNS No. | EN No. | DIN | BS | ASTM | JIS | GOST |
|---|---|---|---|---|---|---|---|
| SS 316 | S31600 | 1.4401 | X5CrNiMo17-12-2 | 316 S31 | A276 / A479 | SUS316 | 03Х17Н14М2 |
| SS 316L | S31603 | 1.4404 | X2CrNiMo17-12-2 | 316 S11 | A276 / A479 | SUS316L | 03Х17Н14М2 |
| SS 316Ti | S31635 | 1.4571 | X6CrNiMoTi17-12-2 | 320 S31 | A276 | SUS316Ti | 08Х17Н13М2Т |
| SS 316H | S31609 | 1.4919 | X6CrNiMo17-13 | 316 S51 | A276 | — | — |
Product Types / Variants
| Product Variant | Process | Description |
|---|---|---|
| SS 316 Turned Parts | CNC Turning | Shafts, bushings, nipples, adapters, spacers |
| SS 316 Milled Parts | CNC Milling | Blocks, manifolds, pads, flanges, profiles |
| SS 316 Bored Housings | CNC Boring | Pump housings, cylinder liners, valve bodies |
| SS 316 Threaded Components | Thread Milling / Tapping | Threaded adapters, ported blocks, union bodies |
| SS 316 Ground Parts | Cylindrical Grinding | Precision shafts, valve spools, plungers, stems |
| SS 316 Complex Parts | 4/5-Axis CNC | Impellers, complex manifolds, multi-feature bodies |
| SS 316 EDM Parts | Wire/Sinker EDM | Precision slots, dies, gauges, internal profiles |
| SS 316 Sub-Assemblies | Turnkey | Machined + assembled + inspected packages |
Applications by Industry
| Industry | CNC Machined SS 316 Application |
|---|---|
| Power Utilities | Turbine shaft sleeves, pump body components, heat exchanger end plates, cable gland adapters |
| Electrical OEMs | Switchgear pivot pins, circuit breaker shafts, enclosure structural inserts, terminal adapters |
| EPC Contractors | Custom turned fittings, pipe support adapters, structural anchor blocks, instrument mounting sockets |
| Oil & Gas | Wellhead adapters, choke body components, chemical injection quills, flowline coupling bodies |
| Chemical Process | Pump impeller inserts, agitator shaft sleeves, reactor nozzle fittings, column support rings |
| Offshore / Marine | Deck fitting adaptors, mooring hardware inserts, hydraulic manifold blocks, corrosion-resistant shafts |
| Instrumentation | Thermowell bodies, pressure port adapters, flow meter body inserts, gauge connection stems |
| Water Treatment | Pump shaft journals, valve body blanks, filter housing components, UV reactor fittings |
Manufacturing Process for SS 316 CNC Machining
1. Enquiry and DFM Review: Customer drawing reviewed for machinability, tolerance feasibility, material grade suitability, and process sequence optimisation.
2. Material Procurement: SS 316 / SS 316L bar, plate, or billet ordered from approved mills with EN 10204 3.1 MTC. Chemical and mechanical property verification on receipt.
3. Process Planning: Machining sequence planned; fixtures and tooling selected; CAM program generated from customer CAD file (STEP, IGES, DWG).
4. Roughing: High-feed roughing passes remove 75–80% of stock; cutting speed optimised to prevent work hardening of SS 316 at cut entry.
5. Semi-Finishing: Dimensional allowance left for final finishing pass; in-process measurement at key stages.
6. Finishing and Special Features: Final dimension machined; threads, bores, grooves, and special features completed to print.
7. Deburring and Cleaning: Vibratory or manual deburring; ultrasonic cleaning; endoscopic check on internal passages.
8. Surface Treatment: Passivation, electropolishing, or other specified treatment.
9. CMM Inspection: Full dimensional report on first article; in-process and final inspection per QC plan.
10. Pressure / Leak Testing: Hydrostatic or pneumatic test at 1.5× operating pressure for pressure-containing parts.
11. Marking, Packing, Export: Electrochemical marking; VCI packing; full export documentation.
Quality Standards and Certifications
| Standard / Certification | Scope |
|---|---|
| ISO 9001:2015 | Quality Management System |
| EN 10204 3.1 / 3.2 | Material Test Certificates |
| ASTM A276 / A479 | SS 316 bar / rod material standard |
| ASTM A967 / AMS 2700 | Passivation standard |
| ISO 286 | Dimensional tolerance (IT grades) |
| ASME B16.5 / B16.11 | Fittings and flange dimensional standard |
| ISO 8434-1 / DIN 2353 | Hydraulic tube fittings |
| PED 2014/68/EU | Pressure Equipment Directive (European supply) |
| RoHS / REACH | Environmental compliance for export |
| CE Marking (on request) | European market compliance |
Why Choose Stainless Steel Fittings India for SS 316 CNC Machining?
- SS 316 specialist — dedicated machining department with optimised cutting parameters for 316 grade
- Full machining scope: turning, milling, grinding, EDM, multi-axis — single vendor, single quality system
- Competitive price: US$ 11.50 / kg — one of India’s most competitive rates for SS 316 machined parts
- In-house CMM, surface roughness lab, hardness testing, and pressure testing
- EN 10204 3.1 MTC on all material; 3.2 witnessed inspection available
- Direct export from India: USA, UK, Germany, UAE, Singapore, Australia, Netherlands, Canada
- DFM support: process feasibility, tolerance review, material grade selection included at quotation
- 22+ years manufacturing experience in stainless steel machining for critical industrial applications
Frequently Asked Questions
Q1: Why is SS 316 preferred over SS 304 for machined components?
SS 316 contains 2–3% molybdenum, which significantly improves resistance to chloride pitting, crevice corrosion, and marine atmospheric corrosion compared to SS 304. In offshore, chemical, coastal, and chloride-laden environments, SS 316 machined parts provide 3–5× longer corrosion life. SS 304 is selected for cost-sensitive indoor applications without significant chloride exposure.
Q2: What is the machinability of SS 316 compared to other stainless grades?
SS 316 has a machinability rating of approximately 45–50% relative to free-machining brass. It is more difficult to machine than SS 303 (free-machining) or SS 304 due to its higher work-hardening tendency and molybdenum content. Correct tooling (carbide grade M25, TiAlN coating), cutting speed, and coolant strategy are essential. Our SS 316 machining team applies grade-specific parameters developed over 22+ years of production experience.
Q3: What is the difference between SS 316 and SS 316L for machined parts?
SS 316L has a maximum carbon content of 0.03% vs. 0.08% for SS 316. The lower carbon in 316L prevents chromium carbide precipitation (sensitisation) in the heat-affected zone during welding. For machined parts that will be welded or used in high-temperature service (above 450°C for prolonged periods), SS 316L is preferred. For standard machined parts without welding, SS 316 and SS 316L are functionally equivalent in corrosion and mechanical performance at ambient temperature.
Q4: What is the price of SS 316 CNC machined parts?
Stainless Steel Fittings India prices SS 316 CNC machined parts at US$ 11.50 per kilogram ex-works India as a base rate for standard turned and milled components. Complex multi-axis parts, ground surfaces, and special treatments may carry a price premium. Volume discounts apply for orders above 500 kg. Contact us with drawings for a firm quotation within 24 hours.
Q5: What is the minimum order quantity for CNC machined SS 316 parts?
Minimum order quantity is 50 kg or 10 pieces. Prototype and sample orders (1–5 pieces) are accepted at a setup charge. For high-volume OEM supply agreements, dedicated capacity allocation and Kanban replenishment are available.
Q6: Can you machine SS 316 to 5-axis complex profiles?
Yes. Our 4-axis and 5-axis CNC machining centres handle complex SS 316 profiles including compound undercuts, angled ports, multi-face features, and 3D curved surfaces. STEP and IGES CAD files are used directly for CAM programming. Single-setup machining of complex parts eliminates datum transfer errors and ensures tighter overall positional accuracy.
Q7: What surface finish options are available after CNC machining of SS 316?
Available surface finishes include: as-machined (Ra 0.8–3.2 μm), ground (Ra 0.1–0.4 μm), electropolished (Ra <0.4 μm, mirror), glass bead blasted (satin Ra 0.8–1.6 μm), pickled and passivated, and PVD coated. Each finish serves specific functional requirements and is certified with a surface roughness measurement report.
Q8: Do you supply EN 10204 3.1 material test certificates with machined SS 316 parts?
Yes. All machined SS 316 and SS 316L parts are supplied with EN 10204 3.1 MTCs showing chemical composition, mechanical properties, heat number, and mill identification. Upgrade to 3.2 witnessed inspection is available on request. Material traceability is maintained lot-by-lot from raw material to finished part.
Q9: What is your export capability for SS 316 machined parts?
We export machined SS 316 parts directly from India to USA, UK, Germany, France, Netherlands, UAE, Saudi Arabia, Singapore, Malaysia, Australia, Canada, South Africa, and other global markets. All exports comply with Indian foreign trade policy; ECCS, COO, and MSDS documentation provided. DHL, FedEx, and sea freight arrangements handled by our logistics team.
Q10: Can you machine SS 316 to ASME pressure vessel or piping standards?
Yes. Machined SS 316 pressure-containing components (nozzle inserts, flange blanks, ported blocks) are manufactured to ASME B16.5, B16.11, B16.48, and ASME Section VIII div. 1 design formulae. Wall thickness calculations, pressure testing at 1.5× MAWP, and ASME material compliance (SA-276, SA-479) are available. PED 2014/68/EU compliance certificates provided for European pressure system applications.
Equivalent Terms in Other Languages
| Language | Terms |
|---|---|
| Spanish | Mecanizado de acero inoxidable 316, CNC acero inox 316, Piezas mecanizadas SS 316 |
| Russian | Обработка нержавеющей стали 316, ЧПУ обработка СС316, Прецизионные детали из нержавейки 316 |
| French | Usinage acier inoxydable 316, CNC inox 316, Pièces usinées SS 316 |
| Portuguese | Usinagem de aço inoxidável 316, CNC aço inox 316, Peças usinadas SS 316 |
| Italian | Lavorazione acciaio inossidabile 316, CNC inox 316, Parti lavorate SS 316 |
Related Products (Internal Links)
- Stainless Steel Machined Parts & Turned Components
- Stainless Steel Milling – SS 316 & 304 Milled Parts
- Stainless Steel Swiss Machining
- Stainless Steel Machined Hydraulic Fittings
- Stainless Steel 37° Flare Tube Fittings
Request a Quote
Contact Stainless Steel Fittings India for SS 316 and SS 316L CNC machined components. Send your drawing (STEP / DWG / PDF) for a firm quotation within 24 hours. Price: US$ 11.50 / kg — volume pricing for OEM agreements. Engineering consultation for DFM, material grade selection, and tolerance feasibility included.
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