ASTM A276 UNS S30300 AISI Stainless Steel 303 Round Bars Manufacturer, Supplier and Stockist in India

ASTM A276 UNS S30300 AISI Stainless Steel 303 Round Bars Manufacturer, Supplier and Stockist in India

Steel House India is a manufacturer, supplier, and stockist of ASTM A276 UNS S30300 AISI Stainless Steel 303 Round Bars for CNC machining, automatic screw machining, precision turned components, and engineering applications requiring high machinability and dimensional stability. SS303 round bars are widely used in machining environments where improved chip control, threading performance, cutting consistency, and reduced tooling wear are important for production efficiency.

AISI 303 stainless steel round bars are sulfur-bearing austenitic stainless steel bars developed for machining-intensive industrial applications. Compared to standard austenitic stainless steel grades, UNS S30300 round bars provide improved machining behavior during drilling, milling, threading, turning, and high-speed machining operations. Stainless steel 303 bright bars are commonly selected for precision engineering systems, industrial shafts, machined fittings, valve components, couplings, and automatic lathe applications requiring improved dimensional accuracy and machining repeatability.

Stainless Steel 303 Round Bars for Precision CNC and Automatic Machining Applications

SS303 round bars are extensively used for machining applications because the sulfur-enhanced chemistry improves free-machining characteristics during production operations. The sulfur content in ASTM A276 Type 303 stainless steel bars improves chip fragmentation during machining and reduces cutting resistance during high-speed turning and threading operations.

UNS S30300 stainless steel round bars are suitable for CNC machining centers, automatic screw machining, precision turned parts, threaded assemblies, couplings, industrial fasteners, and machined engineering components requiring stable dimensional tolerances and smoother machining behavior. Cold drawn stainless steel 303 round bars and bright drawn bars are widely preferred where machining precision and surface consistency are critical during automated manufacturing operations.

Benefits of AISI 303 Stainless Steel Round Bars in Precision Engineering

ASTM A276 stainless steel 303 round bars provide improved machining efficiency across precision engineering and automated machining applications. The controlled sulfur content improves chip breaking during cutting operations and helps maintain smoother machining cycles during turning, tapping, drilling, and threading processes. This allows reduced tooling wear and improved machining productivity during continuous production environments.

Stainless steel 303 bright bars are also preferred for applications requiring improved dimensional consistency and precision tolerance control. Industries manufacturing shafts, valve stems, couplings, machined fittings, and threaded components frequently use SS303 round bars for repeatable machining performance and stable production efficiency across CNC machining systems.

Chemical Composition and Mechanical Properties of SS303 Round Bars

ASTM A276 UNS S30300 stainless steel round bars are manufactured with controlled chemical composition to balance corrosion resistance, machining performance, dimensional stability, and mechanical strength. The sulfur content in AISI 303 stainless steel is specifically maintained to improve machining characteristics during automated and high-speed machining operations.

Chemical Composition of UNS S30300 Stainless Steel Bars

Grade	Carbon C %	Manganese Mn %	Silicon Si %	Sulfur S %	Phosphorus P %	Chromium Cr %	Nickel Ni %	Iron Fe
SS303 Min	—	—	—	0.15	—	17.00	8.00	Balance
SS303 Max	0.15	2.00	1.00	0.35	0.20	19.00	10.00	Balance
ASTM A276 Limit	0.15	2.00	1.00	0.15–0.35	0.20	17–19	8–10	Balance
UNS S30300	0.12	1.80	0.75	0.28	0.15	18.20	8.50	Balance
Bright Bar Grade	0.10	1.60	0.65	0.30	0.12	18.00	8.30	Balance
Cold Drawn Grade	0.11	1.75	0.70	0.25	0.10	18.40	8.70	Balance

Mechanical Properties of AISI 303 Stainless Steel Round Bars

Condition	Tensile Strength MPa	Yield Strength MPa	Elongation %	Hardness HB	Hardness HRB	Density g/cm³	Elastic Modulus GPa	Shear Modulus GPa
Annealed	620	240	50	190	90	8.00	193	77
Cold Drawn	720	420	35	220	96	8.00	193	77
Bright Drawn	740	450	32	225	97	8.00	193	77
Peeled Finish	680	310	42	205	92	8.00	193	77
Precision Ground	760	470	30	228	98	8.00	193	77
Forged Condition	650	280	45	195	91	8.00	193	77

Physical Properties of Stainless Steel 303 Bright Bars

Property Type	Density kg/m³	Melting Range °C	Thermal Conductivity W/mK	Electrical Resistivity µΩ.m	Thermal Expansion µm/m°C	Specific Heat J/kgK	Magnetic Permeability	Elastic Modulus GPa
Standard Value	8000	1400–1450	16.3	0.72	17.3	500	1.02	193
Bright Drawn	8000	1400–1450	16.1	0.71	17.2	500	1.01	193
Cold Drawn	8000	1398–1450	16.0	0.70	17.1	500	1.01	193
Peeled Finish	8000	1400–1448	16.2	0.72	17.3	500	1.02	193
Ground Finish	8000	1400–1450	16.3	0.71	17.2	500	1.01	193

Stainless Steel 303 Round Bar Specifications and Size Range

Steel House India supplies stainless steel 303 round bars in hot rolled, bright drawn, cold drawn, peeled, polished, and centerless ground conditions for machining and engineering applications requiring precision dimensional tolerances and machining-grade consistency. UNS S30300 round bars are processed for precision machining systems, threaded engineering components, automatic lathe operations, and industrial machining environments.

SS303 Round Bar Dimensions and Size Availability

Product Form	Diameter Range	Metric Sizes	Inch Sizes	Standard Length	Finish Type	Manufacturing Process	Custom Cut Length
Bright Bars	3 mm – 100 mm	M3 – M100	1/8" – 4"	3–6 Meter	Bright	Cold Drawn	Yes
Cold Drawn Bars	5 mm – 120 mm	M5 – M120	3/16" – 5"	3–6 Meter	Smooth	Cold Finished	Yes
Hot Rolled Bars	16 mm – 350 mm	M16 – M350	5/8" – 14"	3–6 Meter	Black	Hot Rolled	Yes
Peeled Bars	20 mm – 150 mm	M20 – M150	3/4" – 6"	3–6 Meter	Peeled	Peeled & Straightened	Yes
Polished Bars	10 mm – 80 mm	M10 – M80	3/8" – 3"	3–6 Meter	Polished	Bright Finished	Yes
Forged Bars	130 mm – 500 mm	M130 – M500	5" – 20"	Custom	Rough Forged	Forged	Yes
Centerless Ground Bars	5 mm – 90 mm	M5 – M90	3/16" – 3.5"	3–6 Meter	Ground	Precision Ground	Yes

Stainless Steel 303 Bar Tolerance and Straightness Specifications

Diameter Range	h8 Tolerance mm	h9 Tolerance mm	h11 Tolerance mm	Straightness Deviation	Ovality mm	Surface Roughness Ra µm	Length Tolerance mm
3–6 mm	±0.022	±0.036	±0.090	0.5 mm/m	0.01	0.8	±2
6–12 mm	±0.027	±0.043	±0.110	0.5 mm/m	0.01	0.8	±2
12–30 mm	±0.033	±0.052	±0.130	0.5 mm/m	0.02	0.8	±2
30–50 mm	±0.039	±0.062	±0.160	0.8 mm/m	0.03	1.0	±3
50–80 mm	±0.046	±0.074	±0.190	0.8 mm/m	0.03	1.2	±3
80–120 mm	±0.054	±0.087	±0.220	1.0 mm/m	0.05	1.6	±5
120–180 mm	±0.063	±0.100	±0.250	1.2 mm/m	0.06	1.6	±5

Surface Finish Specifications for SS303 Bright Bars

Finish Type	Roughness Ra µm	Dimensional Accuracy	Straightness	Machining Quality	Surface Appearance	Typical Applications	Manufacturing Method
Bright Finish	0.8	High	Excellent	Excellent	Smooth Metallic	CNC Components	Cold Drawn
Peeled Finish	1.2	High	Very Good	Excellent	Clean Surface	Shafts & Rods	Peeled
Polished Finish	0.4	Precision	Excellent	Precision Grade	Reflective	Precision Engineering	Polished
Black Finish	3.2	Standard	Standard	Moderate	Oxide Scale	Structural Machining	Hot Rolled
Ground Finish	0.2	Precision	Excellent	High Precision	Fine Smooth	Precision Shafts	Ground
Matt Finish	1.8	Medium	Good	Good	Satin Finish	General Engineering	Finished
Turned Finish	1.0	High	Very Good	Excellent	Machined Surface	Turned Components	Turned

Hot Rolled, Cold Drawn and Bright Drawn Stainless Steel 303 Round Bars

Hot rolled stainless steel 303 round bars are generally used for larger diameter engineering applications requiring machining allowances and standard structural machining operations. These bars are suitable for forged components, heavy engineering systems, and industrial fabrication applications requiring machining after processing.

Cold drawn and bright drawn stainless steel 303 round bars provide improved dimensional precision, tighter tolerance control, smoother surface finish, and better straightness consistency for precision machining applications. Bright drawn SS303 bars are widely used for shafts, couplings, threaded rods, valve stems, and automatic machining applications where machining repeatability and surface consistency are important.

Why SS303 Stainless Steel Round Bars are Preferred for High-Speed Machining

ASTM A276 UNS S30300 round bars are preferred for high-speed machining because the sulfur-enhanced chemistry improves chip fragmentation and reduces cutting resistance during machining operations. This allows improved machining consistency during threading, turning, tapping, drilling, and automatic screw machining applications.

Industries manufacturing precision machined components frequently use stainless steel 303 bright bars to reduce tooling wear, improve cutting stability, and maintain dimensional consistency across continuous production machining systems. SS303 round bars are commonly selected for precision turned components and threaded engineering applications where machining efficiency directly affects production output.

Difference Between Stainless Steel 303 and SS304 Round Bars

Stainless steel 303 round bars are specifically optimized for machining applications, while SS304 round bars are primarily selected for corrosion resistance and fabrication performance. The sulfur addition in SS303 improves machinability and chip control during CNC machining operations, whereas SS304 provides improved weldability and corrosion resistance for fabrication-intensive environments.

Applications involving precision machining, automatic screw machining, and threading operations generally prefer SS303 round bars for machining efficiency and tooling performance. Fabrication and welding applications commonly evaluate Stainless Steel 304 Round Bars Manufacturers in India based on corrosion resistance and welding compatibility requirements.

Chemical Composition Comparison of SS303 vs SS304 Round Bars

Grade	Carbon %	Sulfur %	Chromium %	Nickel %	Manganese %	Silicon %	Phosphorus %	Iron
SS303	0.15 Max	0.15–0.35	17–19	8–10	2.00 Max	1.00 Max	0.20 Max	Balance
SS304	0.08 Max	0.03 Max	18–20	8–10.5	2.00 Max	1.00 Max	0.045 Max	Balance
Difference	Higher Carbon	Higher Sulfur	Slightly Lower Cr	Similar Ni	Similar Mn	Similar Si	Higher P	Balance

Machining and Mechanical Comparison Between SS303 and SS304

Property	SS303	SS304
Machinability	Excellent	Moderate
Weldability	Moderate	Excellent
Corrosion Resistance	Good	Excellent
Tool Wear	Low	Higher
Chip Control	Excellent	Moderate
Cutting Speed	High	Moderate
Threading Performance	Excellent	Good
Surface Finish After Machining	Smooth	Moderate
Automatic Machining Suitability	Excellent	Moderate

ASTM A276 Compliance Standards for Stainless Steel 303 Round Bars

ASTM A276 establishes standard specifications for stainless steel bars used in machining, engineering, and industrial fabrication applications. The standard defines dimensional tolerances, straightness limits, mechanical property requirements, finish conditions, and inspection parameters for stainless steel round bars.

ASTM A276-compliant stainless steel 303 round bars are manufactured to maintain machining consistency, dimensional stability, and material reliability across precision engineering and automated machining applications. Procurement teams sourcing machining-grade stainless steel bars often verify ASTM compliance for tolerance control, inspection standards, and material consistency.

Equivalent Standards for UNS S30300 Stainless Steel Round Bars

ASTM Standard	AISI Grade	UNS Number	EN Equivalent	DIN Equivalent	JIS Standard	Werkstoff No.	ISO Grade
ASTM A276	303	S30300	X10CrNiS18-9	1.4305	SUS303	1.4305	303
ASTM A582	303	S30300	X8CrNiS18-9	1.4305	SUS303Se	1.4305	303Se

Material Testing and Inspection Standards for SS303 Bars

Testing Method	Inspection Type	Acceptance Standard	Frequency	Certification	Applicable Standard	Verification Purpose	Inspection Category
PMI Testing	Spectrometer	Grade Compliance	Batch Wise	Available	ASTM	Material Verification	Chemical
Tensile Testing	UTM	Strength Compliance	Batch Wise	Available	ASTM E8	Mechanical Validation	Mechanical
Hardness Testing	Brinell/Rockwell	Hardness Range	Batch Wise	Available	ASTM E18	Hardness Validation	Mechanical
Ultrasonic Testing	UT Inspection	Internal Soundness	As Required	Available	ASTM A388	Defect Detection	NDT
Dimensional Inspection	Micrometer	Tolerance Compliance	100%	Available	ASTM A276	Dimensional Verification	Dimensional
Surface Inspection	Visual & Ra Test	Finish Quality	100%	Available	ASTM A480	Surface Validation	Visual
Straightness Inspection	Dial Gauge	Straightness Limit	Batch Wise	Available	ASTM A276	Straightness Control	Dimensional

Stainless Steel 303 Round Bars for Precision Engineering and Machined Components

UNS S30300 stainless steel round bars are widely used for CNC machined shafts, couplings, threaded rods, valve stems, industrial fasteners, machined fittings, precision engineering components, and automatic screw machining applications requiring stable machining performance and dimensional consistency.

Cold drawn stainless steel 303 round bars and bright bars are extensively used across machining environments requiring tighter tolerances, smoother finish quality, and repeatable machining behavior during continuous production operations. Industries manufacturing high-volume precision components frequently use SS303 round bars to improve machining productivity and tooling efficiency.

Stainless Steel 303 Bright Bars for Precision Machined Parts

Stainless steel 303 bright bars are preferred for machining applications requiring precision dimensional tolerances, improved straightness, and smoother surface finish during CNC operations. Bright drawn bars are widely used for threaded components, shafts, couplings, precision fittings, and machined engineering assemblies requiring stable machining behavior.

Centerless ground and peeled stainless steel 303 round bars provide improved finish quality and dimensional consistency for precision engineering systems and high-speed machining applications. These bars are commonly selected for precision turned components and industrial machining systems requiring repeatable machining accuracy.

Why Choose Steel House India for Stainless Steel 303 Round Bars

Steel House India supplies ASTM A276 UNS S30300 stainless steel round bars for machining-intensive industrial applications requiring dimensional consistency, machining-grade material quality, precision tolerances, and controlled surface finish standards. The supplied SS303 round bars are processed for CNC machining compatibility and automated production machining systems.

As a trusted Stainless Steel Round bar manufacturer in India , Steel House India supplies stainless steel 303 bright bars, cold drawn bars, peeled bars, and precision machining bars for industrial engineering applications requiring machining stability, ASTM-compliant specifications, and inspection-controlled material quality.

Stainless Steel Round Bar Supplier for Precision Machining and Industrial Engineering Requirements

Applications involving CNC machining, threaded engineering components, precision shafts, automatic screw machining, valve systems, and industrial fabrication assemblies require stainless steel round bars with stable machining behavior and controlled dimensional tolerances. ASTM A276 Type 303 stainless steel round bars are widely selected across machining-intensive industries due to improved machinability, smoother chip control, and machining efficiency during high-speed production operations.

Steel House India supplies stainless steel 303 round bars, bright drawn bars, cold drawn bars, and machining-grade stainless steel products for industrial engineering applications requiring dimensional stability, precision machining compatibility, and reliable material consistency across automated machining environments.