301-1/2 Hard Tempered Stainless Steel Sheet & Coil - AMS 5518
301-1/2 Hard tempered stainless steel strikes a valuable balance between strength and formability, making it one of the most versatile tempers in the 301 family. Cold‑worked to a medium‑high strength level, it offers significantly greater tensile and yield strength than annealed 301 while still allowing more bending, shaping, and deep‑drawing capability than the Full Hard condition. This temper develops a controlled amount of strain‑induced martensite, giving it enhanced fatigue resistance and partial magnetism without sacrificing the corrosion performance expected of chromium‑nickel stainless steels. Because of this combination of properties, 301 ½ Hard is widely used for springs, brackets, clips, structural components, and any application that needs a strong yet workable stainless steel.
Because of its strength, 301-1/2 requires robust cutting methods. The best options include laser cutting (clean, precise), waterjet cutting (no heat-affected zone), and shearing (only for thinner gauges; high tonnage required). 301-1/2 Hard is often supplied with a bright finish and responds well to mechanical polishing, brushing, and passivation, especially after welding or heavy fabrication.
- Inventory & Specs
- Chemical Composition
- Physical Properties
- Mechanical Properties
- Datasheet
- Additional Info
- FAQs
Inventory Size Ranges for 301-1/2
| Type | Thickness | AMS Standards | UNS | ASME | Get a Quote |
|---|---|---|---|---|---|
| Coil | 0.010" - 0.125" | AMS 5518 | UNS S30100 | ASME SA 666 | Get a Quote |
| Sheet | 0.010" - 0.125" | AMS 5518 | UNS S30100 | ASME SA 666 | Get a Quote |
| Precision Reroll Strip | 0.0008" - 0.015" | Get a Quote |
Characteristics of 301-1/2
Cold working raises strength significantly compared to annealed 301. 301-1/2 has an ultimate tensile strength of ~170 ksi (1170 MPa), a yield strength of ~120 ksi (860 MPa), and shear strength of ~110 ksi (730 MPa). This makes 301-1/2 ideal for structural and spring applications requiring strength without the brittleness of Full Hard. 201-1/2 performs well in atmospheric and mild chemical environments. It has slightly lower corrosion resistance than 304 due to its lower nickel content. 301-1/2 is susceptible to carbide precipitation during welding, so welded areas may lose corrosion resistance. 301-1/2 demonstrates moderate heat resistance and oxidation resistance up to 1550°F (843°C). It is not recommended for continuous service above 1600°F. 301-1/2 Hard is partially magnetic due to strain-induced martensite from cold working.
Working with 301-1/2
301-1/2 has a very high work-hardening rate, so addition deformation increases strength rapidly which can cause cracking. 301-1/2 can be formed using moderate bends, light roll-forming, and shallow drawn shapes. Machining 301-1/2 is challenging because it is already significantly hardened. It is recommended to use carbide tooling, maintain high feed and moderate speed to avoid work-hardening, avoid tool dwell, and use coolant to reduce heat and galling. Welding 301-1/2 is possible, but not ideal. If welding is necessary, use low-heat input processes, expect to lose 1/2 hard properties near the weld, and consider post-weld cleaning or passivation.
Other industry standards we comply with:
- EN 1.4310
- PWA-LCS
- GE Aircraft Engine (GT193)
- GE Aviation S-SPEC-35 AeDMS S-400
- RR SABRe Edition 2
- DFARS Compliant
Common Trade Names
- ATI 301 (™ Allegheny Technologies)
Industry Applications for 301-1/2
- Aircraft structural parts
- Trailer bodies
- Architectural (roof drainage/door frames, etc.)
- Auto body trim and wheel covers
- Utensils and tablewear
- Conveyor parts
Chemical Composition
| Element | Min | Max | |
|---|---|---|---|
| C | Carbon | - | 0.15 |
| Mn | Manganese | - | 2.00 |
| P | Phosphorus | - | 0.045 |
| S | Sulfur | - | 0.03 |
| Si | Silicon | - | 1.00 |
| Cr | Chromium | 16.00 | 18.00 |
| Ni | Nickel | 6.00 | 8.00 |
| N | Nitrogen | - | 0.10 |
Physical Properties
| Property | Value |
|---|---|
| Density | 0.2850 lb/in3 (7.88g/cm3) |
| Melting Range | 2250 - 2950°F (1399 - 1421°C) |
| Specific Gravity | 8.03 |
| Modulus of Elasticity in Tension | 28x106 psi (193 GPa) |
| Magnetic Permeability | 1.02 Max @ 200 H |
| Temperature Range | Coefficients | ||
|---|---|---|---|
| °C | °F | cm/cm°C | in/in/°F |
| 20-100 | 68-212 | 16.6·10-6 | 9.2·10-6 |
| 20-300 | 68-572 | 17.6·10-6 | 9.8·10-6 |
| 20-500 | 68-932 | 18.6·10-6 | 10.3·10-6 |
| 20-700 | 68-1292 | 19.5·10-6 | 10.8·10-6 |
| 20-871 | 68-1600 | 19.8·10-6 | 11.0·10-6 |
| Temperature Range | Coefficients | ||
|---|---|---|---|
| °C | °F | W/m·K | Btu/(hr/ft²/hr/°F/ft) |
| 20-100 | 68-212 | 16.30 | 9.40 |
| 20-500 | 68-932 | 21.40 | 12.4 |
| Temperature Range | J/kg°K | Btu/lb/°F | |
|---|---|---|---|
| °C | °F | ||
| 0-100 | 32-212 | 500 | 0.12 |
| Temperature Range | microhm-cm | microhm-in | |
|---|---|---|---|
| °C | °F | ||
| 20 | 68 | 72 | 28.3 |
| 100 | 212 | 78 | 30.7 |
| 200 | 392 | 86 | 33.8 |
| 400 | 752 | 100 | 39.4 |
| 600 | 1112 | 111 | 43.7 |
| 800 | 1472 | 121 | 47.6 |
| 900 | 1652 | 126 | 49.6 |
Mechanical Properties
| Condition | Tensile Strength, Min. | 0.2% Yield Strength, Min. | Elong. In 2" (50mm) | ||
|---|---|---|---|---|---|
| Ksi | MPa | Ksi | MPa | %, Min. | |
| Annealed | 75 | 515 | 30 | 205 | 40 |
| 1/4 Hard | 125 | 862 | 75 | 517 | 25 |
| 1/2 Hard | 150 | 1034 | 110 | 758 | 18* |
| 3/4 Hard | 175 | 1207 | 135 | 931 | 12* |
| Full Hard | 185 | 1276 | 140 | 965 | 9* |
* Value shown for thickness greater than 0.015 in. (.038mm).
Datasheet
Additional Info
A Brief History of 301-1/2 Hard
301 stainless steel was introduced as part of the early 300‑series austenitic stainless steels, developed in the mid‑20th century to provide corrosion‑resistant alloys with tunable strength through cold working rather than heat treatment. As industries demanded stronger, lighter stainless steels, manufacturers began producing controlled tempers—1/4 Hard, 1/2Hard, 3/4 Hard, Full Hard—each offering a different balance of strength and formability. The 1/2 Hard temper quickly became one of the most widely used because it delivered high strength without the brittleness of the Full Hard condition, making it ideal for structural and spring applications.
How 301-1/2 Was Developed
301-1/2 Hard stainless steel evolved from the base 301 alloy through controlled cold reduction, optimized chemistry, and precision rolling technology. The 1/2 Hard temper is produced by rolling the steel to a specific level of cold working, increasing its tensile strength, yield strength, and fatigue resistance while still preserving moderate ductility. The chemistry of 301-1/2 allows strain-induced martensite to form during cold work, which is the key to its high strength. Advances in rolling mills allowed manufacturers to reliably produce consistent tempers, including the ½ Hard condition, which became a standard for aerospace and industrial applications.
Early Applications of 301-1/2
When first introduced, 301-1/2 Hard was quickly adopted in industries that needed strong, corrosion‑resistant stainless steel that could still be formed. Common early uses included aircraft components, springs, automotive trim and brackets, rail hardware, conveyor and industrial components, and architectural panels and trim.
How 301-1/2 is Used Today
Today, 301 ½ Hard remains one of the most versatile stainless tempers, widely used across transportation, aerospace, industrial, and consumer sectors.
- Automotive: Seatbelt components, structural reinforcements, brackets, clamps, railcar panels
- Aerospace: Springs, fasteners, lightweight structural parts, clamps, brackets
- Architecture: Elevator doors and trim, decorative panels, structural supports
- Industrial: Conveyor components, shims, springs, clips, precision-formed parts
- Consumer Products: Appliance components, hand tools, knife springs and mechanisms
Your Trusted Supplier of 301-1/2 Hard
United Performance Metals supplies coil and sheet sizes 0.010" - 0.125" and precision rerolled strip sizes 0.0008" - 0.015".
Product FAQs
It refers to 301 stainless steel that has been cold-rolled to the 1/2 hard temper, giving it significantly higher strength than annealed or 1/4 Hard material while still retaining moderate formability.
Yes, 301-1/2 can be formed but with limitations. It can handle moderate bending and shaping but is not suitable for deep drawing. Larger bend radii are recommended due to its high strength and springback.