Material
Stainless Steel Machining & Custom Parts
Precision Machining India supplies OEMs and procurement teams worldwide with stainless Steel Machined Parts, made in our ISO 9001:2015 certified CNC machining plant in Pune, India.
ISO 9001:2015 Certified
Documented quality management system
Mitutoyo Quality Inspection
Calipers, micrometers, height gauge, DTIs
Export-Ready Packaging
VCI film, ISPM-15 wooden crates
RFQ Response in 24 Hours
Quote within one working day
NDA Available
Your drawings stay confidential
On this page15 sections
Direct answer
Can you machine stainless steel, and in which grades?
Yes. Precision Machining India machines stainless steel parts to customer drawings at its ISO 9001:2015 certified plant in Pune, India, in SS 303, 304, 316/316L, 410, 420, 17-4 PH. Work is turned on CNC turning centres and milled on a 3-axis VMC with a 800 × 500 × 400 mm bed, holding ±0.01 mm typical, ±0.005 mm on selected diameters. Grades are stocked or sourced against your specification, and EN 10204 3.1 mill certificates are supplied on request. Quantities run from a single prototype to 10,000+ pieces with no fixed minimum, and RFQs are answered within 24 hours.
- Grades: SS 303, 304, 316/316L, 410, 420, 17-4 PH
- Tolerance: ±0.01 mm typical, ±0.005 mm on selected diameters
- Finishes: As-machined (Ra 1.6–3.2 µm), fine turned (Ra 0.8 µm), passivation and electropolishing through partners
- Typical parts: pump shafts, valve stems, food-grade fittings and marine hardware
- Quantities: single prototype to 10,000+ pieces, no fixed minimum order
- Documents: dimensional inspection report with the shipment, EN 10204 3.1 mill certificate on request
At a glance
Materials & technical specifications
Stainless Steel machining notes: Work-hardens if tools rub; we use rigid set-ups, positive-rake coated carbide and constant chip load.
- Process
- Stainless Steel Machining
- Materials
- Stainless Steel
- Grades
- SS 303, 304, 316/316L, 410, 420, 17-4 PH
- Key properties
- Corrosion resistant, strong and hygienic. 316 adds molybdenum for chloride and marine resistance.
- Standard tolerance
- ±0.01 mm typical, ±0.005 mm on selected diameters
- Surface finish
- As-machined (Ra 1.6–3.2 µm), fine turned (Ra 0.8 µm), passivation and electropolishing through partners
- Max turning size
- Ø400 × 1200 mm (conventional), bar work on CNC lathes
- Max milling envelope
- 800 × 500 × 400 mm (VMC)
- Threading
- M3–M32 auto tapping; metric, BSP, NPT, UNC/UNF
- Batch size
- 1 prototype to 10,000+ pieces
Stainless Steel Machined Parts: overview
SS 304, 316, 410 and 17-4 PH parts turned and milled. Stainless is cut with rigid set-ups, sharp coated carbide and flood coolant to manage work hardening.
Every order is programmed in VISI or Delcam CAM, machined on CNC lathes and VMC, and inspected in our Mitutoyo quality lab before it is packed and shipped.
Stainless Steel Machining capability
We run stainless steel machining on dedicated machines, so prototypes, pilot lots and production runs all follow the same documented process. Common parts include shafts, flanges, bushings, valve components, fittings and custom fasteners.
Before quoting, our engineers review your STEP, IGES or PDF drawing for machinability and suggest changes that reduce cost without affecting function.
- CNC turning centres (LMW, Jyoti, Ace Micromatics): Shafts, bushings, fittings, turned plastic parts
- Vertical machining centre (VMC) (Ace Micromatics, FANUC control): 3-axis milling, bed 800 × 500 × 400 mm
- Auto tapping machines (M3 to M32 capacity): High-volume internal threading
- Conventional lathe (Uma Enterprises): Turning up to Ø400 × 1200 mm
- Band saw (Rajlaxmi): Bar stock cutting and blank preparation
Tolerances & surface finish
Standard capability for this work is ±0.01 mm typical, ±0.005 mm on selected diameters. Bores can be held to H7 and bearing seats to h6/g6 fits. Where your drawing calls for tighter limits, we agree the critical characteristics up front and record them on the inspection report.
Surface finish is typically Ra 1.6–3.2 µm as machined, with Ra 0.8 µm achievable on turned sealing and bearing surfaces. Plastics are finished with sharp tools to avoid smearing and burrs.
Plating, anodising, passivation and heat treatment are arranged through qualified partners and re-inspected in-house before packing.
Quality inspection process
Quality is built into every step under our ISO 9001:2015 management system. Raw material is checked against its mill certificate, the first article is fully inspected against the drawing, and in-process checks run at defined intervals.
Every shipment includes a dimensional inspection report, with material test certificates (EN 10204 3.1) on request.
- Mitutoyo digital vernier calipers
- Mitutoyo height gauge
- Granite surface plate
- Mitutoyo outside micrometers
- Inside calipers and bore gauges
- Dial test indicators
Stainless steel grades we machine
Each grade behaves differently on the machine and in service. Name the one you need on the drawing — this is what each is normally chosen for.
SS 303
Free-machining austenitic
- Condition
- Annealed bar, sulphur added to break the chip
- Key property
- Cuts fastest of the austenitic grades; corrosion resistance a little below 304
- Typical use
- High-volume turned fittings, spacers and studs in indoor or dry service
SS 304 / 304L
General-purpose austenitic
- Condition
- Annealed bar and plate, non-magnetic as supplied
- Key property
- Around 18% chromium and 8% nickel; sound in water, steam and most foodstuffs
- Typical use
- Food-grade fittings, general shafts, housings and brackets
SS 316 / 316L
Molybdenum-bearing austenitic
- Condition
- Annealed; the lower carbon of 316L suits assemblies that will be welded
- Key property
- Molybdenum lifts resistance to chlorides, seawater and many process chemicals
- Typical use
- Pump shafts, valve stems, marine hardware, chemical-service parts
SS 410
Hardenable martensitic
- Condition
- Machined in the annealed condition; hardening and tempering through partners
- Key property
- Hardenable for wear resistance; magnetic, with moderate corrosion resistance
- Typical use
- Valve stems, wear sleeves and shafts that run against a seal
SS 420
Hardenable martensitic, higher carbon
- Condition
- Annealed bar; hardened and tempered by partners to the range you specify
- Key property
- Reaches a higher hardness than 410 and resists abrasion better
- Typical use
- Wear parts, spindles and bushes in abrasive duty
17-4 PH
Precipitation-hardening
- Condition
- Machined in condition A; H900 to H1150 ageing by agreement
- Key property
- High strength with corrosion resistance in the same region as 304
- Typical use
- Highly loaded shafts, stems and pins
Choosing between aluminium and stainless steel
Aluminium is the material most often quoted as an alternative to stainless steel for this kind of part. The differences that change a decision are below.
| Criterion | Aluminium Light, fast to machine, lower piece price | Stainless Steel Corrosion resistance and strength in one material |
|---|---|---|
| Machinability and cycle time | The quickest metal we run: high spindle speeds, sharp polished tooling and short cycle times. 2011 is the easiest, 7075 the most demanding. | Work-hardens if a tool rubs, so cuts are taken at moderate speed with rigid set-ups and a constant chip load. 303 cuts fastest, 316 slowest. |
| Tolerance we hold | ±0.01 mm typical | ±0.01 mm typical, ±0.005 mm on selected diameters |
| Service temperature | Strength falls noticeably above about 150 °C and the T6 temper softens under prolonged heat, so it is not a high-temperature material. | Austenitic grades stay serviceable from cryogenic temperatures upwards and resist scaling in air to around 800 °C, though strength falls away above roughly 450 °C. |
| Corrosion and chemical resistance | The natural oxide handles atmospheric and fresh-water exposure. 7075 and 2011 are markedly less corrosion resistant and normally need anodising. | Good general resistance to water, steam and foodstuffs; 316 adds molybdenum for chlorides and seawater. Reducing acids such as hydrochloric still attack it. |
| Relative cost | Low material cost per part by volume and the shortest cutting times of the metals, which usually makes it the cheapest finished metal component. | Mid-range material cost with longer cycle times than brass or aluminium, so the machining share of the piece price is higher. |
Values are indicative figures from published grade data, given to guide specification rather than to qualify a design; confirm them against the mill or polymer data sheet for your service conditions. Material selection remains your design responsibility. Grades are stocked or sourced per order, with EN 10204 3.1 certificates on request.
Industries we serve
This work is used across electronics & electrical, general engineering, aerospace and medical devices. Electronics & Electrical customers, for example, need insulating, dimensionally stable plastic parts free from contamination.
Our core customers are corporate OEMs in automotive, hydraulics, pumps & valves and general engineering, plus multinational companies that need PTFE, Nylon, Delrin and PEEK parts machined to drawing.
Export packaging & logistics
We export to 45+ countries from Nhava Sheva (JNPT), with sea transit of about 4–7 days to the Gulf, 18–28 days to Europe and the UK, and 25–35 days to North America. Air freight is available for urgent orders.
All parts are protected with VCI film and packed in ISPM-15 crates. We quote EXW, FOB or CIF to suit your logistics.
Why source from India with us
India has become a leading China+1 destination for precision machined components. For international buyers, we combine competitive piece prices with an ISO 9001:2015 quality system, English-speaking engineers and drawings worked to ISO, DIN and ASME standards.
You get a 24-hour RFQ response, an NDA on request, one engineer as your contact, and inspection reports with every shipment.
- ISO 9001:2015 certified
- Mitutoyo quality inspection
- Export-ready packaging
- RFQ response in 24 hours
- NDA available
Specifying stainless steel on your drawing
A drawing that answers these points can be quoted in one pass and machined without a query.
Put this on the drawing
- State the grade and its condition — SS 303, annealed or hardened and tempered — not simply "stainless steel".
- Put ISO 286 fits only on the functional diameters and bores (h6, g6, H7) and leave the rest to ISO 2768-m.
- Give Ra values where they matter: Ra 0.8 µm on bearing and sealing surfaces, as-machined Ra 1.6–3.2 µm elsewhere.
- Mark the datums, and reference any runout or concentricity requirement to them.
- Ask for the EN 10204 3.1 mill certificate on the purchase order if the heat number has to be recorded at goods-in.
- Say whether plating, anodising, passivation or heat treatment is required, and whether the dimensions apply before or after it.
What causes scrap, delay or extra cost
- A blanket ±0.01 mm on every dimension: it loads inspection time onto features that do not need it.
- Hardness or a heat-treated condition with no stated verification method. Heat treatment is done by partners and covered by their certificate; there is no in-house hardness testing.
- Leaving the grade to the supplier. A free-machining grade cuts cost but is not interchangeable with a corrosion-resistant one.
- Sharp internal corners at pocket walls and shoulder roots — give a radius or call out an undercut.
- Thin walls and long unsupported lengths that distort; tell us the free length so steadies and centres can be planned.
- Reports from a CMM. Inspection here uses Mitutoyo micrometers, bore gauges, a height gauge and dial test indicators on a granite surface plate.
How to order
Getting a quote for stainless Steel Machined Parts is simple:
- Send your drawing (PDF) and 3D model (STEP or IGES) with material, quantity and destination.
- Our engineers review it and send a quote with lead time within 24 hours.
- Approve samples or a first-article report for new parts.
- We machine, inspect, pack and ship with full export documents.
What to weigh when buying stainless steel parts
Properties quoted here are those of the material as supplied. Pressure ratings and application approval stay with your own design and qualification process.
Tolerance and fit
Standard capability on stainless steel is ±0.01 mm typical, ±0.005 mm on selected diameters. Bores are held to H7 and bearing seats to h6 or g6; tighter limits are agreed feature by feature.
Service temperature
Austenitic grades stay serviceable from cryogenic temperatures upwards and resist scaling in air to around 800 °C, though strength falls away above roughly 450 °C.
Corrosion resistance
Good general resistance to water, steam and foodstuffs; 316 adds molybdenum for chlorides and seawater. Reducing acids such as hydrochloric still attack it.
Machinability and price
Mid-range material cost with longer cycle times than brass or aluminium, so the machining share of the piece price is higher.
Traceability
Bar is cut on the band saw and identified with its heat number, so each batch can be traced to its mill certificate. EN 10204 3.1 certificates come from the mill on request.
Surface treatment
As-machined (Ra 1.6–3.2 µm), fine turned (Ra 0.8 µm), passivation and electropolishing through partners. Partner processing is re-inspected here before packing, and parts leave in VCI anti-rust film inside ISPM-15 heat-treated crates.
Frequently asked questions
Get a quote in 24hWhat tolerances can you hold for stainless Steel Machined Parts?
Standard capability is ±0.01 mm typical, ±0.005 mm on selected diameters. Bores to H7 and shaft fits to h6/g6 are routine; tighter limits are agreed per drawing.
Are you ISO certified?
Yes. We are ISO 9001:2015 certified. We do not hold AS9100 or ISO 13485, but we work under customer quality plans and supply full inspection reports and material certificates.
What files do you need for a quote?
A PDF drawing with tolerances plus a STEP or IGES model is ideal. Include material, quantity, finish and destination. We reply within 24 hours.
What is your minimum order quantity?
There is no fixed MOQ. We machine single prototypes, low-volume batches and high-volume production runs.
Do you export?
Yes. We export to 45+ countries across North America, Europe, the Middle East, Africa, Asia-Pacific and Latin America.
Which Stainless Steel grades do you machine?
SS 303, 304, 316/316L, 410, 420, 17-4 PH. Other grades on request.
Keep exploring
Related capabilities, materials and markets
Everything below is machined in the same Pune plant to the same ISO 9001:2015 system. Follow whichever is closest to the part you are sourcing.
Capabilities & related parts
5Export markets
8Request for quotation
Send your drawing. Get a quote in 24 hours.
Upload STEP, IGES or PDF files. NDA available on request. Quoting: Stainless Steel Machined Parts.