631 Stainless Steel Round Pipe
Grade: 631/17-7PH/S17700
Size:
Seamless: 6mm*1mm-720mm*50mm
Welded: 12mm*0.5mm-2000mm*100mm
Coiled: 4mm*0.3mm-32mm*3mm
Standard: ASTM A312, ASTM A213 etc.
Surface: No.1(Pickling), Bright(Polished)
- Fast Shipping / Ready Stock
- ISO 9001 Direct Factory
- Custom Cutting & Processing
- 100% MTC & SGS Inspection Supported
631 Stainless Steel Pipe, commonly known as 17-7PH, is a precipitation-hardening stainless steel designed to provide high strength, good corrosion resistance, and useful spring properties. Its mechanical performance can be tailored through conditioning and aging treatments. The grade is used in aerospace structures, springs, diaphragms, pressure components, chemical equipment, and specialized mechanical systems where high strength and corrosion resistance are required.
Chemical Composition
| Element | Content (wt. %) |
| C | ≤0.090 |
| Si | ≤1.00 |
| Mn | ≤1.00 |
| P | ≤0.040 |
| S | ≤0.030 |
| Cr | 16.0–18.0 |
| Ni | 6.5–7.75 |
| Mo | — |
| N | — |
| Other | Al: 0.75–1.50; Fe: Balance |
Mechanical Properties
| Condition | Tensile Strength | Yield Strength (0.2%) | Elongation | Hardness |
| Condition A, reference | ≈965 | ≈380 | ≥20 | ≈≤255 HB |
- Aerospace components
- Springs and spring tubing
- Diaphragms
- Pressure components
- Chemical equipment
- Specialized mechanical systems


631 Stainless Steel Pipe, commonly known as 17-7PH, is a precipitation-hardening stainless steel designed to provide high strength, good corrosion resistance, and useful spring properties. Its mechanical performance can be tailored through conditioning and aging treatments. The grade is used in aerospace structures, springs, diaphragms, pressure components, chemical equipment, and specialized mechanical systems where high strength and corrosion resistance are required.
Chemical Composition
| Element | Content (wt. %) |
| C | ≤0.090 |
| Si | ≤1.00 |
| Mn | ≤1.00 |
| P | ≤0.040 |
| S | ≤0.030 |
| Cr | 16.0–18.0 |
| Ni | 6.5–7.75 |
| Mo | — |
| N | — |
| Other | Al: 0.75–1.50; Fe: Balance |
Mechanical Properties
| Condition | Tensile Strength | Yield Strength (0.2%) | Elongation | Hardness |
| Condition A, reference | ≈965 | ≈380 | ≥20 | ≈≤255 HB |
- Aerospace components
- Springs and spring tubing
- Diaphragms
- Pressure components
- Chemical equipment
- Specialized mechanical systems






