Complete Range of 17-4 PH Bolts

International Standards & Global Designations for 17-4 PH Bolts

To serve clients worldwide, RAYCHIN LIMITED manufactures 17-4 PH bolts to the following national and international specifications. This ensures full compliance for projects in the Americas, Europe, Asia, and the Middle East.

ASTM A564 GR.630 AMS 5604 AMS 5643 1.4542 SUS630 X5CrNiCuNb16-4 UNS S17400 17-4PH

Chemical Composition (Weight %) – 17-4 PH Precipitation Hardening Stainless Steel

Our 17-4 PH bolts are produced from melts that strictly conform to the limits below per ASTM A564 / AMS 5604. The precise addition of copper and niobium enables age-hardening to achieve high strength.

Expert note: The Nb/Cu ratio ensures consistent precipitation of coherent copper-rich clusters during aging. This yields tensile strengths up to 190 ksi (1310 MPa) in the H900 condition while retaining good ductility. All raw material is positively identified by PMI (Positive Material Identification) and certified with mill test reports.

Complete Mechanical Properties of 17-4 PH Bolts (by Heat Treatment per ASTM A564/A564M)

17-4 PH bolts are typically supplied in one of eight standard heat treatment conditions. RAYCHIN LIMITED recommends the appropriate temper based on your strength vs. toughness requirements. The data below represent minimum values for bolts (longitudinal direction) per ASTM A564/A564M Table 3.

Condition H900 (480°C / 900°F) – Highest Strength

Condition H925 (495°C / 925°F) – Slightly lower strength, improved toughness

Condition H1025 (550°C / 1025°F) – Best combination of strength & toughness

Condition H1075 (580°C / 1075°F) – Improved ductility

Condition H1100 (595°C / 1100°F) – Enhanced toughness

Condition H1150 (620°C / 1150°F) – Maximum stress corrosion resistance

Condition H1150M (760°C + 620°C / 1400°F + 1150°F) – Double aged, maximum ductility

Condition H1150D (620°C + 620°C / 1150°F + 1150°F) – Double aged, improved properties

Additionally, 17-4 PH bolts exhibit excellent fracture toughness (K_IC values from 50 to 110 MPa√m depending on temper) and very high fatigue strength. Our test certificates include actual values from each production lot.

High Temperature Performance of 17-4 PH Bolts

17-4 PH stainless steel is widely used in applications requiring retention of mechanical properties at elevated temperatures. The material maintains excellent strength up to 400°C (752°F), beyond which copper-rich precipitates begin to coarsen.

Temperature-Dependent Strength Retention (Condition H900)

Studies demonstrate that yield strength of 17-4 PH decreases with increasing temperature, with thermal softening becoming significant above 400°C. Fatigue strength in the long-life regime at 300°C can be superior to room temperature performance due to surface oxidation and thermal activation mechanisms. For applications requiring strength retention above 400°C, special heat treatments or reinforced variants may be considered.

Thermal Stability Limits

Corrosion Resistance of 17-4 PH Bolts

17-4 PH stainless steel offers excellent corrosion resistance comparable to 304 stainless steel in many environments, attributed to its high chromium content (15-17.5%) which forms a protective Cr₂O₃ passive layer. The corrosion behavior is significantly influenced by heat treatment condition and aging parameters.

Corrosion Performance in Different Environments

Effect of Heat Treatment on Corrosion Rate

Critical Corrosion Considerations for Bolts

• Sensitization: Aging above 495°C can cause chromium carbide precipitation at grain boundaries, leading to chromium depletion and increased susceptibility to intergranular corrosion.
• Pitting Resistance: Increases when aging temperature rises from 480°C to 550°C, but decreases at 620°C due to reversed austenite formation and precipitate coarsening.
• Optimal Aging: Solution treatment at 1040°C followed by aging at 480°C for 4 hours provides the best combination of hardness and corrosion resistance.
• Comparison to 304: 17-4 PH offers comparable corrosion resistance to 304 stainless steel in many environments, with significantly higher strength.

Corrosion Engineering Note: For critical applications in aggressive environments, RAYCHIN LIMITED can provide passivation, specialized coatings (Xylan, PTFE, silver plating), or recommend optimal heat treatment conditions (H1150 for maximum stress corrosion cracking resistance). Third-party corrosion testing per ASTM G31, G48, or G61 available upon request.

Why RAYCHIN LIMITED – The 17-4 PH Bolt Authority