ステンレス鋼、オーステナイト系
303 Stainless Steel (S30300) Bar
クロム・ニッケル系オーステナイトステンレス鋼の快削棒。.
Stainless steel type 1.4305 is popularly known as grade 303 stainless steel.
Grade 303 is the most readily machineable of all the austenitic grades of stainless steel.
303 stainless steel は オーステナイト系ステンレス鋼 specifically engineered for improved machinability while maintaining good corrosion resistance. It is widely used in precision-machined components where ease of machining is critical.
The machineable nature of grade 303 is due to the presence of sulphur in the steel composition. Whilst the sulphur improves machining, it also causes a decrease in the corrosion resistance and a slight lowering of the toughness. The corrosion resistance of type 303 is lower than that for 304. The toughness is still excellent as with other austenitic grades.
Property data given in this document is typical for bar products covered by EN Standards. ASTM, or other standards may cover products sold. It is reasonable to expect specifications in these standards to be similar but not necessarily identical to those given in this datasheet.
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レンジ
| 製品形態 | インペリアルサイズ | メートルサイズ |
| Round Bar Bright Drawn H9 | 1⁄8" - 1" | 2.0mm - 25.0mm |
| Round Bar Smooth Turned H9⁄10 | 1" - 3" | 25.0mm - 60.0mm |
| Round Bar Peeled K12/K16 | 3 1⁄4" - 8" | |
| Hexagon Bar | 0.250" - 2.750" | 7.0mm - 50.0mm |
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303 Stainless Steel Related Specifications
| システム / スタンダード | 国・地域 | グレード / 役職 |
| AISI | アメリカ | 303 |
| 国連 | インターナショナル | S30300 |
| EN / W.Nr. | ヨーロッパ | 1.4305 |
| EN名 | ヨーロッパ | X8CrNiS18-9 |
| ASTM A276 | アメリカ | 303 (bars, shapes) |
| ASTM A582 | アメリカ | 303 (free-machining bars) |
| 日本工業規格 | 日本 | SUS303 |
| GB (common usage) | 中国 | 12Cr18Ni9 (free-machining type) |
プロパティ
化学組成
1.4305 Steel
EN 10088-3
| 化学元素 | %プレゼント |
| カーボン（C） | 0.00 - 0.10 |
| クロム（Cr） | 17.00 - 19.00 |
| マンガン (Mn) | 0.00 - 2.00 |
| ケイ素 (Si) | 0.00 - 1.00 |
| リン (P) | 0.00 - 0.05 |
| 硫黄（S） | 0.15 - 0.35 |
| ニッケル（Ni） | 8.00 - 10.00 |
| Copper (Cu) | 0.00 - 1.00 |
| Nitrogen (N) | 0.00 - 0.11 |
| Iron (Fe) | Balance |
機械的特性
Bar Up to 160mm Dia / Thickness
EN 10088-3
| 機械的性質 | 価値 |
| プルーフ・ストレス | 190 Min MPa |
| 引張強度 | 500 to 750 MPa |
| 伸び A50 mm | 35 Min % |
| 硬度 ブリネル | 230 Max HB |
一般的な物理的特性
| 物理的性質 | 価値 |
| 密度 | 8.03 g/cm³ |
| Melting Point | 1455 °C |
| Thermal Expansion | 17.3 x 10-6/K |
| 弾性係数 | 193 GPa |
| 熱伝導率 | 16.3 W/m.K |
| Electrical Resistivity | 0.72 x 10-6 Ω .m |
Applications of 303 Stainless Steel
303 stainless steel は オーステナイト系ステンレス鋼 specifically designed for improved machinability while retaining good corrosion resistance. It is ideal for precision machined components in industrial and engineering applications.
1. Mechanical and Engineering Components
Gears, shafts, and bolts
Nuts, screws, and fasteners
Bearings and bushings
2. Automotive and Aerospace Applications
Engine and transmission components
Fuel and hydraulic system parts
Precision fittings and connectors
3. Industrial Machinery
Pump and valve components
Instrumentation and control equipment
Threaded parts and precision assemblies
4. Food, Beverage, and Pharmaceutical Industry
Equipment requiring machinability and corrosion resistance
Fittings, shafts, and small mechanical parts in processing equipment
概要
303 stainless steel is widely used for applications requiring high machinability, good corrosion resistance, and mechanical strength. Its design makes it particularly suitable for precision machined parts in mechanical, automotive, aerospace, industrial, and food processing applications.
Characteristics of 303 Stainless Steel
303 stainless steel は オーステナイト系ステンレス鋼 developed for enhanced machinability while maintaining good corrosion resistance and mechanical properties. It is particularly suitable for precision components requiring extensive machining.
1.化学組成
内容 chromium (17–19%) そして nickel (8–10%).
Includes sulfur or selenium additives to improve machinability.
Low carbon content reduces risk of carbide precipitation during machining.
2.耐食性
Good resistance to oxidation, mild acids, and atmospheric corrosion.
Slightly lower corrosion resistance than 304 stainless steel due to sulfur content.
で優れたパフォーマンスを発揮する。 indoor, dry, or mildly corrosive environments.
3.機械的特性
Moderate 引張強さと硬さ.
素晴らしい 延性と靭性 for forming and machining.
Maintains stable properties across a wide range of temperatures.
4. Machinability
Exceptional machinability compared to standard austenitic stainless steels.
Easily machined with high-speed steel (HSS) or carbide tools.
プロデュース continuous chips and smooth surfaces, reducing tool wear.
5. Formability and Fabrication
可能 cold worked, drawn, and formed, though work hardens slightly.
Welding is possible but may reduce corrosion resistance in the heat-affected zone.
6.アプリケーション
Gears, shafts, screws, and fasteners
Automotive and aerospace components
Pump and valve parts
Precision machinery and instrumentation
概要
303 stainless steel is characterized by excellent machinability, good corrosion resistance, and moderate strength. Its unique properties make it ideal for precision-machined components in mechanical, automotive, aerospace, and industrial applications.
追加情報
製作
Fabrication of 303 Stainless Steel
303 stainless steel は オーステナイト系ステンレス鋼 optimized for machinability, making it widely used in precision components and industrial applications. While it offers good corrosion resistance, special considerations are needed during fabrication due to its sulfur content, which can affect weldability.
1.成形
Cold working: 303 can be formed using standard techniques such as bending, stamping, and drawing.
Hot working: Limited due to the risk of 結晶粒の成長と耐食性の低下; care must be taken to control temperature and cooling rates.
2.機械加工
303 is highly machinable, with continuous chips and smooth finishes.
Ideal for turning, milling, drilling, and tapping with high-speed steel (HSS) or carbide tools.
Lubrication and proper tool geometry improve surface finish and reduce tool wear.
3.溶接
Welding of 303 is possible but not recommended for critical corrosion-resistance applications.
Sulfur content may lead to hot cracking or reduced corrosion resistance 熱影響を受けたゾーンで。.
Post-weld stress relief and corrosion-resistant coatings may be required.
4. Joining and Assembly
こんな人に向いている mechanical fastening, bolting, and riveting.
Adhesive bonding is possible in non-critical corrosion environments.
5. Surface Finishing
可能 polished, passivated, or electroplated to enhance corrosion resistance.
Surface treatments improve appearance and long-term durability in indoor or mildly corrosive environments.
概要
303 stainless steel offers excellent machinability and good formability. While welding requires caution due to sulfur content, it can be cold worked, machined, and surface-finished effectively for precision components in mechanical, automotive, and industrial applications.
溶接性
Weldability of 303 Stainless Steel
303 stainless steel は オーステナイト系ステンレス鋼 engineered for high machinability. Its weldability, however, is limited due to the sulfur or selenium content, which can lead to cracking and reduced corrosion resistance in welded areas.
1.一般的な溶接特性
Weldable using common methods: TIG (GTAW), MIG (GMAW), and resistance welding are possible.
High sulfur content can cause hot cracking and poor weld bead quality.
Not recommended for critical corrosion-resistance applications without precautions.
2.溶接技術
TIG (GTAW) welding: Provides controlled heat input, minimizing the risk of cracking.
MIG (GMAW) welding: Possible with proper filler material and welding parameters.
Spot and resistance welding: Suitable for thin sections and non-critical parts.
3.充填材
用途 304または308ステンレス鋼フィラーロッド/ワイヤー 耐食性を維持する。.
Avoid fillers that are incompatible with high-sulfur 303 steel.
4. Preheating and Post-Weld Treatments
Preheating is generally not required, but stress relief may help reduce cracking in thicker sections.
Post-weld passivation or surface treatment improves corrosion resistance in the weld zone.
5.実践的考察
Welding should be performed by experienced operators due to the risk of cracking.
Machined 303 components are often assembled mechanically or by adhesive bonding instead of welding.
For welded assemblies requiring corrosion resistance, consider using 304 or 304L stainless steel instead.
概要
303 stainless steel has limited weldability because of its sulfur content. While welding is possible using TIG, MIG, or resistance methods, precautions such as appropriate filler materials, controlled heat input, and post-weld treatments are necessary. For critical corrosion-resistant applications, alternative grades like 304 or 304L are preferred.
加工性
Machinability of 303 Stainless Steel
303 stainless steel は オーステナイト系ステンレス鋼 specially designed for enhanced machinability. Its composition, which includes sulfur or selenium additives, allows it to be machined easily and efficiently compared to standard 304 stainless steel.
1.加工特性
プロデュース short, easily controlled chips, reducing the risk of tool clogging.
必要 lower cutting forces than standard austenitic stainless steels.
Machinable using high-speed steel (HSS) or carbide tools.
2.推奨工具
工具材料： High-speed steel (HSS), carbide, or cobalt tools.
切断速度： Higher than 304 stainless steel; reduces tool wear.
Lubrication: Use cutting fluids to improve surface finish and reduce heat.
3.機械加工
回っている： Excellent surface finish and dimensional accuracy.
Milling and Drilling: Smooth operation with minimal work hardening.
Tapping and Threading: Produces clean threads without galling.
4.メリット
Reduces tool wear and machining time.
最小化 work hardening, making post-machining operations easier.
プロデュース consistent surface finishes suitable for precision components.
5. Applications Benefiting from Machinability
Gears, shafts, screws, and fasteners
Automotive and aerospace precision parts
Pump, valve, and instrumentation components
概要
303 stainless steel is characterized by exceptional machinability, に最適である。 precision-machined parts in mechanical, automotive, aerospace, and industrial applications. Its composition allows for efficient machining with reduced tool wear and excellent surface finish, while maintaining good corrosion resistance in non-critical environments.
耐食性
Corrosion Resistance of 303 Stainless Steel
303 stainless steel は オーステナイト系ステンレス鋼 optimized for machinability, while retaining good corrosion resistance in many environments. However, its corrosion resistance is slightly lower than standard 304 stainless steel due to the addition of sulfur or selenium.
1.一般的な耐食性
抵抗 酸化および大気腐食 under normal conditions.
で優れたパフォーマンスを発揮する。 indoor, dry, or mildly corrosive environments.
Not recommended for highly corrosive, chloride-rich, or marine environments.
2. Corrosion in Chemicals
Good resistance to organic acids, mild alkalis, and non-oxidizing solutions.
Sulfur content may reduce performance in strong acids, oxidizing environments, or seawater.
3. Stress and Crevice Corrosion
Generally resistant to general corrosion, but prone to pitting or crevice corrosion in chloride-rich solutions.
Avoid use in applications requiring maximum corrosion resistance without protective coatings.
4. Surface Protection
可能 passivated to restore a clean, corrosion-resistant surface.
Polishing and surface treatments improve long-term corrosion resistance.
5. Practical Applications
Indoor mechanical components and precision parts
Instrumentation and fasteners exposed to mild environments
Automotive and aerospace parts not exposed to aggressive chemicals
概要
303 stainless steel offers good corrosion resistance, suitable for indoor and mildly corrosive environments, but is less resistant than 304 or 316 stainless steel due to its sulfur content. It is ideal for machined components where ease of machining is prioritized, and extreme corrosion resistance is not critical.
冷間加工
Cold Working of 303 Stainless Steel
303 stainless steel は オーステナイト系ステンレス鋼 designed primarily for high machinability. .それは次のようなものだ。 cold worked, but certain limitations apply due to its composition and sulfur content.
1.冷間加工特性
可能 formed, bent, drawn, or stamped アニール状態で.
Work hardens faster than standard 304 stainless steel due to austenitic structure.
Excessive cold working may reduce ductility and increase risk of cracking during machining.
2.テクニック
曲げと成形： Suitable for moderate bends; use proper tooling to avoid surface cracks.
深いドローイング： Possible, but large reductions may require intermediate annealing.
Stamping: Works well for small to medium parts in annealed condition.
3.メリット
冷間加工で改善 強度と硬度 in the formed part.
Enables creation of precision shapes without high-temperature processing.
4.制限事項
Sulfur content may lead to surface defects or micro-cracking if deformation is too severe.
Not recommended for applications requiring maximum corrosion resistance after heavy cold working.
Annealing may be required after extensive forming to restore ductility.
5. Practical Applications
Small mechanical components, fasteners, and gears
Precision parts in automotive, aerospace, and industrial machinery
Components that require moderate forming before machining
概要
303 stainless steel can be cold worked effectively for forming, bending, stamping, and drawing operations. While it gains 強度と硬度 through cold working, careful process control is needed to avoid cracking and maintain corrosion resistance, making it suitable for machined and precision-formed components.
熱処理
Heat Treatment of 303 Stainless Steel
303 stainless steel は オーステナイト系ステンレス鋼 primarily designed for enhanced machinability. Due to its composition, particularly the high sulfur content, 303 has limited hardenability and heat treatment options compared to martensitic or ferritic stainless steels.
1.アニール
目的 Relieves internal stresses, improves ductility, and softens the steel for easier machining or forming.
プロセス
ヒート・トゥ・ヒート 1010-1120°C (1850-2050°F).
Hold at temperature for a sufficient time to allow stress relief.
Cool rapidly in water or air 耐食性を維持する。.
2.ストレス解消
目的 Reduces residual stresses caused by machining, cold working, or forming.
プロセス
ヒート・トゥ・ヒート 450-650°C (840-1200°F).
パーツの厚みに応じて1～2時間保持する。.
室温までゆっくり冷ます。.
Helps prevent 歪み、反り、ひび割れ during subsequent fabrication.
3.硬化
303 stainless steel is not intended for hardening by heat treatment.
It achieves moderate strength through cold working rather than quenching and tempering.
4. Practical Considerations
Avoid high-temperature service or heat treatment that can lead to carbide precipitation, reducing corrosion resistance.
Post-heat treatment passivation may be applied to restore surface corrosion resistance.
5. Summary
303 stainless steel has 限られた熱処理オプション due to its sulfur content. アニールとストレス除去 が主な治療法である。 relieve internal stresses and restore ductility. Strengthening is achieved mainly through 冷間加工 rather than conventional hardening. This makes 303 ideal for machined, precision components rather than high-strength, heat-treated parts.
耐熱性
Heat Resistance of 303 Stainless Steel
303 stainless steel は オーステナイト系ステンレス鋼 optimized for high machinability, with good general corrosion resistance. Its heat resistance is moderate, making it suitable for applications with intermittent or mild elevated temperatures but not for continuous high-temperature exposure.
1.温度限界
Recommended for use up to 870°C intermittently.
Continuous service temperatures should generally not exceed 425–450°C (800–840°F) to maintain mechanical properties and corrosion resistance.
2.耐酸化性
Offers moderate resistance to oxidation at elevated temperatures.
Sulfur content can slightly reduce oxidation resistance compared to standard 304 stainless steel.
3. Strength at Elevated Temperature
維持 moderate tensile strength and toughness at elevated temperatures.
Extended exposure to high temperatures may result in reduction of corrosion resistance and potential scaling.
4. Applications
Components exposed to moderate heat and mechanical stress
Fasteners, gears, and shafts in low- to medium-temperature environments
Industrial machinery operating below 425°C (800°F)
5.実践的考察
以下には適さない。 high-temperature continuous service or oxidizing environments above 870°C.
For higher temperature resistance, consider 304H, 321, or 310 stainless steels.
概要
303 stainless steel has moderate heat resistance, suitable for intermittent or mild elevated temperature applications. Its primary advantages remain high machinability and good corrosion resistance, に最適である。 precision components operating at low to moderate temperatures.
ホットワーキング
Hot Working of 303 Stainless Steel
303 stainless steel は オーステナイト系ステンレス鋼 designed for enhanced machinability. While it can undergo hot working, there are important considerations due to its sulfur content, which can reduce ductility and increase the risk of cracking at high temperatures.
1.熱間加工特性
こんな人に向いている forging, rolling, or extrusion at elevated temperatures.
必要 careful temperature control to prevent surface cracking or internal stresses.
Hot working improves formability but does not significantly increase hardness, as 303 is not heat-treatable for hardening.
2.推奨温度範囲
Annealed temperature: 1010–1120°C (1850–2050°F) for shaping or forging.
Avoid overheating, as temperatures above 1120°C (2050°F) may cause grain growth and reduced corrosion resistance.
コントロール 冷却 (air or water quench) helps preserve mechanical properties.
3.メリット
Hot working allows for large deformations without excessive tool wear.
Reduces mechanical stresses and improves formability for subsequent machining or cold working.
4.制限事項
Sulfur content can lead to localized cracking or surface defects if hot worked improperly.
Not suitable for applications requiring high hardness through heat treatment—strength is primarily achieved through 冷間加工.
5. Practical Applications
Forged or rolled components requiring subsequent machining
Shafts, gears, and industrial fittings where moderate formability is needed
Automotive or mechanical parts formed before final machining
概要
303 stainless steel can be 効果的に働いた within controlled temperature ranges. While it allows good formability for industrial and mechanical components, care must be taken to avoid cracking and maintain corrosion resistance, as 303 is optimized for machinability rather than high-temperature strength.
