Patriot Bolt machines Alloy 20 fasteners from certified ASTM B473 bar (UNS N08020). Alloy 20 is a nickel-iron-chromium alloy with copper and molybdenum, developed for sulfuric acid, and it resists chloride stress corrosion cracking.
This page brings together the Alloy 20 fasteners we make, the bar property limits, and how Alloy 20 compares with other corrosion-resistant alloys.
Alloy 20 at a Glance
- Material
- Alloy 20, UNS N08020
- Bar specification
- ASTM B473 / ASME SB473
- Strength
- 80 ksi min tensile, 35 ksi min yield (annealed)
- Key elements
- 32–38% Ni, 19–21% Cr, 3–4% Cu, 2–3% Mo
- Products
- Stud bolts, nuts, hex cap screws, socket head cap screws
Alloy 20 Fasteners We Machine
Choose a product to see its standards and options. Every order ships with mill test reports traceable to the heat.
Alloy 20 Stud BoltsFull Alloy 20 page
Alloy 20 Heavy Hex NutsMatching nut
Alloy 20 Hex Cap ScrewsMade in Alloy 20Alloy 20 Socket Head Cap ScrewsMade in Alloy 20Alloy 20 Mechanical Properties
| Condition | Tensile, min | Yield (0.2%), min | Elongation, min |
|---|---|---|---|
| Annealed | 80 ksi | 35 ksi | 30% |
| Annealed and strain hardened, to 2 in | 90 ksi | 60 ksi | 15% |
Full chemistry is on the Alloy 20 stud bolts page.
Alloy 20 vs. Other Corrosion-Resistant Alloys
| Grade | Strength, min (tensile / yield) | Typical use |
|---|---|---|
| Alloy 20 (B473, annealed) | 80 / 35 ksi | Sulfuric acid; chloride stress corrosion cracking |
| 316 stainless (A193 B8M Class 1) | 75 / 30 ksi | General corrosion resistance; mild chemicals |
| Incoloy 825 (B425, annealed) | 85 / 35 ksi | Sulfuric and phosphoric acid; seawater |
| Hastelloy C-276 (B574, annealed) | 100 / 41 ksi | Severe acids, chlorides and sour service |
Compare all grades in the Fastener Materials Matrix.
Alloy 20 Fastener FAQ
What is Alloy 20 used for?
Mainly sulfuric acid service, plus other acids and chloride-bearing streams where 316 stainless does not hold up.
Which Alloy 20 fasteners does Patriot Bolt make?
We machine Alloy 20 stud bolts, nuts, hex cap screws and socket head cap screws, as well as custom parts made to your drawing.
How does Alloy 20 compare with Hastelloy C-276?
C-276 handles more severe acids and chlorides, at a higher cost. Alloy 20 is a common choice for sulfuric acid service.
Do Alloy 20 fasteners come with certifications?
Yes. Patriot Bolt is ISO 9001:2015 certified, and every Alloy 20 order includes mill test reports traceable to the heat and a certificate of conformance to your purchase order.
Request a Quote
Send us the product, size, specification and quantity, or upload your drawing. Call (281) 581-0176 or request a quote.