631 Stainless Steel Sheet: High-Strength, Precipitation-Hardening Excellence

Meta Description: Discover 631 stainless steel sheet with high strength (up to 1650 MPa), excellent corrosion resistance, and ideal for aerospace & medical applications. Get the best 631 stainless steel sheet price.

Introduction

631 Stainless Steel Sheet (also known as 17-7PH) is a precipitation-hardening semi-austenitic stainless steel that combines exceptionally high strength with excellent corrosion resistance. This material is widely used in demanding applications such as aerospace, medical devices, spring manufacturing, and pressure vessels, where both strength and reliability are critical.

With a yield strength of up to 1650 MPa, 631 stainless steel sheet ranks as one of the highest-strength precipitation-hardening stainless steels, making it perfect for industries requiring high-performance materials. The precipitation-hardening process enhances its strength, while maintaining good machinability in its annealed condition. It also offers superior corrosion resistance in a wide range of environments, including chloride-rich atmospheres, which is why it’s favored in aerospace structural parts, turbine components, surgical tools, and high-performance springs.

Whether you're seeking 631 stainless steel sheet for sale or the best 631 stainless steel sheet distributor, this material offers versatility and reliability across industries. It’s available in multiple conditions such as RH950, CH900, and TH1050, each tailored to meet specific performance requirements.

Product Overview & Key Advantages

Highest Strength in PH Stainless Steels: With up to 1650 MPa of yield strength and excellent fatigue performance, 631 stainless steel sheet is the material of choice for high-stress applications.
Outstanding Corrosion Resistance: It offers superb resistance to chloride stress corrosion cracking and general corrosion, making it highly effective in harsh environments.
Versatile Applications: Commonly used in aerospace, medical, spring manufacturing, turbine components, and pressure vessels.
Precipitation Hardening Process: The material undergoes solution annealing followed by aging to achieve optimal mechanical properties, including high tensile strength and hardness.
Machinability: Excellent machinability in the annealed condition, which enables precision fabrication of complex components.
Variety of Available Conditions: Available in multiple tempers such as RH950, CH900, TH1050, TH1100, allowing for tailored strength and hardness to suit different application needs.

Chemical Composition

Element	Percentage (%)
Chromium (Cr)	16.0–18.0
Nickel (Ni)	6.5–7.75
Aluminum (Al)	0.75–1.5
Carbon (C)	≤ 0.07
Manganese (Mn)	≤ 2.0
Silicon (Si)	≤ 1.0
Phosphorus (P)	≤ 0.04
Sulfur (S)	≤ 0.03
Iron (Fe)	Balance

631 stainless steel composition features high chromium (16–18%) for excellent corrosion resistance, nickel (6.5–7.75%) for enhanced ductility and toughness, and aluminum (0.75–1.5%) for precipitation hardening. The low carbon content ensures the prevention of carbide precipitation during welding and maintains the steel’s overall integrity.

Mechanical Properties

Condition	Yield Strength (MPa)	Ultimate Tensile Strength (MPa)	Elongation (%)	Hardness (HRC)
Solution Annealed	550	750	40	20–30
RH950	950	1200	10	38–42
CH900	900	1200	12	38–42
TH1050	1050	1400	8	42–46
TH1100	1100	1450	6	46–48

631 stainless steel exhibits outstanding strength across different heat treatment conditions. RH950, CH900, and TH1050 offer progressively higher yield strengths, making them suitable for increasingly demanding applications where both strength and durability are crucial. The hardness increases with heat treatment, achieving values of up to 48 HRC for the TH1100 condition.

Physical Properties

Property	Value
Density (g/cm³)	7.80
Thermal Conductivity (W/m·K)	15.4
Specific Heat (J/kg·K)	500
Electrical Resistivity (Ω·cm)	0.00073
Magnetic (after hardening)	Yes

The density of 631 stainless steel is 7.80 g/cm³, typical for high-performance materials. It has moderate thermal conductivity at 15.4 W/m·K, ensuring that it maintains thermal stability under high-stress, high-temperature conditions. Magnetic properties are present after hardening, which is important for certain aerospace and medical applications.

631 vs 630 vs 17-7PH vs 304 vs 316 vs 17-4PH Sheet Comparison

Property	631 Stainless Steel	630 Stainless Steel	17-7PH Stainless Steel	304 Stainless Steel	316 Stainless Steel	17-4PH Stainless Steel
Yield Strength (MPa)	1650	1100	1100	250	290	1300
Corrosion Resistance	Excellent	Good	Excellent	Good	Excellent	Excellent
Hardness (HRC)	38–48	35–42	38–42	20–30	25–35	35–40
Heat Treatment	RH950, CH900, TH1050	Solution Annealed	RH950, CH900	Annealed	Annealed	H1150
Cost	Moderate	Moderate	Moderate	Low	High	High

631 stainless steel stands out in terms of strength and hardness when compared to other stainless steels, such as 17-7PH and 304 stainless steel. Its performance surpasses 630 stainless steel and 304 in high-strength, high-temperature applications. However, 316 stainless steel offers superior corrosion resistance, though it lacks the strength of 631.

Available Specifications

Thickness (mm)	Width (mm)	Length (mm)	Finish Types
0.3–50	1000–2000	Up to 12000	2B, No.1 Hot-rolled, Pickled, Polished, Brushed

We offer 631 stainless steel sheets in a wide range of thicknesses (0.3–50 mm) and widths (1000–2000 mm), with lengths up to 12 meters. Available finishes include 2B, No.1 hot-rolled, pickled, polished, and brushed, ensuring that you can choose the perfect finish for your project’s specific requirements.

Heat Treatment & Precipitation Hardening Guide

631 stainless steel undergoes a solution annealing process at 1040°C to optimize its properties before undergoing cold-rolling for CH900. Aging conditions such as RH950, TH1050, and TH1100 allow for the material to achieve hardness values from 38 HRC to 48 HRC, ideal for applications requiring high strength and fatigue resistance.

Major Applications

Aerospace structural parts
Aircraft springs & fasteners
Medical instruments
Pressure vessels
High-strength bellows
Turbine components
Nuclear reactor parts
Surgical tools
High-performance springs
Chemical processing equipment

631 stainless steel sheet is widely used in aerospace, medical, high-performance springs, turbine parts, and other critical industries, where superior strength and corrosion resistance are essential.

Product Images

Hot-rolled 631 stainless steel sheets ready for shipment

Professional infographic 631 stainless steel sheet data sheet + mechanical properties chart

Real-application collage – 631 sheets used in aerospace components, medical instruments, and high-performance springs

Why We Are the Best 631 Stainless Steel Sheet Distributor

We are the largest stockholder of 631 stainless steel sheet, offering the fastest delivery worldwide. With direct mill contracts, ultrasonic testing, and precision cutting, we guarantee top-notch quality and the most competitive pricing.

FAQ Section

What is the maximum hardness of 631 stainless steel sheet?
- 38–48 HRC, depending on the heat treatment condition.
Is 631 stainless steel sheet magnetic after hardening?
- Yes, it becomes magnetic after hardening.
Can 631 sheet be welded?
- Yes, using 17-7PH filler.
What condition offers maximum strength?
- The CH900 condition offers the highest strength.
Is 631 sheet suitable for cryogenic applications?
- Yes, it retains good strength and toughness at cryogenic temperatures.

Conclusion + Urgent Call-to-Action

Request a quote today for 631 stainless steel sheet with 24-hour response. Contact us via WhatsApp, email, phone, or live chat for immediate assistance.

631 Stainless Steel Plate: Superior Strength and Corrosion Resistance for Demanding Applications

Meta Description: Discover 631 stainless steel plate with excellent corrosion resistance, strength up to 1650 MPa, and superior fatigue performance. Ideal for aerospace, medical, and high-performance structural applications.

Introduction

631 Stainless Steel Plate is a semi-austenitic precipitation-hardening stainless steel that offers the highest strength among precipitation-hardening grades (up to 1650 MPa). It combines outstanding mechanical properties with excellent corrosion resistance, making it a perfect choice for aerospace, medical, and high-performance structural applications. The versatility of 631 stainless steel plate in demanding industries such as aerospace, defense, and medical devices stems from its ability to maintain high strength and fatigue resistance while offering excellent resistance to corrosion in harsh environments.

Unlike standard 304 or 316 stainless steel, 631 stainless steel can be hardened through a precipitation hardening process, which not only increases its strength but also enhances its fatigue resistance and machinability. The ability to undergo heat treatment such as RH950, CH900, and TH1050 makes it highly versatile for high-performance applications where both strength and corrosion resistance are required.

At [Your Company Name], we are proud to be one of the leading 631 stainless steel plate suppliers, offering the best quality plates at competitive prices, with quick global delivery and customization options. Whether you need plates for aerospace structural components, medical instruments, or high-performance springs, we have the expertise and stock to meet your needs.

Product Overview & Key Advantages

Highest Strength Among PH Grades: With a tensile strength of up to 1650 MPa, 631 stainless steel plate offers exceptional strength, ideal for demanding structural components in aerospace and defense.
Superior Corrosion Resistance: 631 stainless steel provides outstanding resistance to corrosive environments, making it perfect for applications in medical devices, turbine components, and chemical processing.
Excellent Fatigue Performance: With enhanced fatigue resistance, 631 stainless steel plate ensures long-lasting performance even in dynamic loading applications, such as aerospace brackets and high-pressure springs.
Versatility in Heat Treatment: The ability to undergo multiple heat treatments like RH950, CH900, and TH1050 enables users to tailor the material properties to suit specific engineering needs, ensuring optimal strength and durability.
Machinability in Annealed Condition: In its annealed condition, 631 stainless steel plate offers excellent machinability, allowing for precise cutting, shaping, and finishing to meet your custom requirements.

Detailed Advantages:

High Strength-to-Weight Ratio: 631 stainless steel provides high strength while maintaining a lightweight profile, making it ideal for applications where weight reduction is crucial, such as aircraft components and surgical tools.
Fatigue Resistance for High-Performance Applications: Its fatigue resistance makes 631 stainless steel plate the preferred choice for applications that are subjected to cyclic loading or vibration.
Versatility in Industries: Ideal for use in industries like aerospace, medical, nuclear, automotive, and oil & gas, 631 stainless steel offers versatility in highly demanding and specialized environments.
Global Compliance: Plates meet the ASTM A240 and ASME SA240 standards, ensuring consistent quality and performance across all industries.

Chemical Composition

Element	Percentage (%)
Chromium (Cr)	16–18
Nickel (Ni)	6.5–7.75
Aluminum (Al)	0.75–1.5
Manganese (Mn)	≤ 2.0
Silicon (Si)	≤ 1.0
Carbon (C)	≤ 0.07
Phosphorus (P)	≤ 0.04
Sulfur (S)	≤ 0.03

631 stainless steel plate (UNS S17700) has a semi-austenitic structure that incorporates chromium, nickel, and aluminum, combined with low carbon levels, to enhance corrosion resistance and allow for precipitation hardening. This composition delivers a unique combination of high strength, durability, and resistance to oxidation and sulfur contamination, ideal for extreme applications.

Mechanical Properties

Condition	Yield Strength (MPa)	Ultimate Tensile Strength (MPa)	Elongation (%)	Hardness (HRC)
Solution Annealed	850	1050	25	30–35
RH950	950	1150	20	35–40
CH900	900	1100	15	38–42
TH1050	1050	1250	10	40–45
TH1100	1100	1300	5	42–48

631 stainless steel plate exhibits superior yield strength and tensile strength in its hardened conditions, with hardness levels reaching up to 48 HRC in TH1100. This makes it ideal for high-stress applications such as aerospace structural components and medical device manufacturing.

Physical Properties

Property	Value
Density (g/cm³)	7.75
Thermal Conductivity (W/m·K)	16.3
Magnetic (after hardening)	Yes

The density of 631 stainless steel plate is 7.75 g/cm³, with a thermal conductivity of 16.3 W/m·K, which makes it suitable for applications requiring thermal stability and resistance to thermal cycling. Additionally, 631 remains magnetic after hardening, which is beneficial in certain industrial applications.

631 vs 630 vs 17-7PH vs 304 vs 316 vs 17-4PH Plate Comparison

Property	631 Stainless Steel Plate	17-7PH Stainless Steel Plate	630 Stainless Steel Plate	304 Stainless Steel Plate	316 Stainless Steel Plate	17-4PH Stainless Steel Plate
Yield Strength (MPa)	1300	1300	1000	250	290	1100
Corrosion Resistance	Excellent	Excellent	Good	Good	Excellent	Excellent
Hardness (HRC)	38–48	38–44	28–44	20–30	25–35	35–40
Heat Treatment	RH950, CH900, TH1050, TH1100	H900, H925	H900, H925	Annealed	Annealed	H900, H925
Cost	Moderate	Moderate	Moderate	Low	High	Moderate

631 stainless steel plate excels in strength and corrosion resistance compared to 304 and 316 grades, making it ideal for high-performance applications where strength-to-weight ratio and corrosion resistance are critical.

Available Specifications

Thickness (mm)	Width (mm)	Length (mm)	Finish
3–100	1000–3000	Up to 12000	No.1 Hot-Rolled, Pickled, 2B, Polished, Brushed

631 stainless steel plate is available in a variety of thicknesses, widths, and finishes to meet the needs of aerospace, medical, and high-performance applications. Choose from pickled, bright annealed, and polished finishes for enhanced performance.

Heat Treatment & Precipitation Hardening Guide

Solution Annealing: 1040°C
Aging Conditions: RH950, CH900, TH1050, TH1100
Achievable Hardness: 38–48 HRC

The precipitation hardening process allows 631 stainless steel plate to achieve high hardness and superior mechanical properties, especially in conditions such as CH900 or RH950.

Major Applications

Aerospace: Structural plates, aircraft components, turbine casings
Medical: Surgical tools, medical instrument components



* **High-Performance Springs**: For high-stress environments
* **Nuclear**: Reactor parts, fuel cells
* **Chemical Processing**: Pressure vessel shells, pump bodies
* **High-Strength Bellows**: For aerospace and medical devices

## Exactly THREE Image Placeholders

* Image 1: **Polished 631 stainless steel plate in RH950 condition stacked in warehouse**
* Image 2: **Professional infographic 631 stainless steel plate data sheet + strength vs aging temperature curve**
* Image 3: **Real-application collage – 631 plates used in aerospace brackets, medical surgical tools, high-strength springs, and aircraft structural parts**

## Why We Are the Best 631 Stainless Steel Plate Distributor

* **Largest Stock**: **Ready stock** in all **conditions** with fast **global delivery**.
* **Precision Cutting & Beveling**: Customization options for **every need**.
* **Full Quality Testing**: **100% ultrasonic testing**, **PMI testing**, **hardness testing**.
* **Competitive Prices**: Direct relationships with mills for **unbeatable pricing**.
* **Certified Products**: Full **EN 10204 3.1/3.2 certificates**.

## FAQ Section

1. **What is the maximum hardness of 631 stainless steel plate?**
2. **Is 631 stainless steel plate magnetic after hardening?**
3. **631 vs 17-7PH differences (they are the same grade)**
4. **Can 631 plate be welded and what filler?**
5. **Recommended condition for maximum strength (CH900)**
6. **Corrosion resistance in chloride environments**
7. **Minimum order quantity**
8. **Lead time for RH950 condition 631 plate**
9. **Is 631 plate suitable for cryogenic applications?**

## Conclusion + Urgent Call-to-Action

For **high-performance** and **reliable** **631 stainless steel plates**, **request a quote today**. We offer **fast responses** and **global delivery**. Contact us via **WhatsApp**, **email**, or **phone** to get started.