What Materials Are Used in Shot Peening?

Shot peening is a surface engineering technique that strengthens components by bombarding them with small, high-velocity particles. These particles—known as peening media—play a crucial role in the process. Just as important is understanding which materials can be treated with shot peening to achieve performance improvements.

Visit Vibra’s Shot Peening Service Page

This article dives into both sides:

• What types of shot peening media are used?

• Which materials can be shot peened effectively?

What Is Shot Peening Media?

Shot peening media is the material used to strike the surface of a component during peening. It must be spherical, durable, and controlled in size and hardness to achieve consistent compressive stress.

Here are the most common types of shot peening media:

1. Cast Steel Shot

• Most widely used in industrial applications

• High durability and reusability

• Available in various hardness levels (typically 40–65 HRC)

• Ideal for aerospace, automotive, and heavy machinery

2. Cut Wire Shot

• Made from chopped wire, then conditioned to be spherical

• More consistent in shape and hardness than cast shot

• Available in carbon steel, stainless steel, aluminum, brass

• Often used for parts requiring tight tolerances and high fatigue strength

3. Glass Beads

• Softer, non-metallic media

• Used for non-ferrous metals or delicate surfaces

• Creates a smooth finish with less aggressive deformation

• Popular in medical, aerospace, and electronics industries

4. Ceramic Beads

• Harder than glass but still non-metallic

• High wear resistance and long lifespan

• Ideal for titanium and aerospace alloys

• Non-contaminating, suitable for critical applications

5. Other Specialty Media

• Plastic media: Used for low-stress applications or polymers

• Aluminum shot: Used for lightweight materials or to match part composition

Which Materials Can Be Shot Peened?

Shot peening is used across a wide range of metals and alloys—especially those prone to fatigue, stress corrosion, or surface damage.

Here are the primary material categories that benefit from shot peening:

1. Steel and Alloys

• Carbon steel, alloy steel, and stainless steel

• Common in automotive, energy, and construction

• Peened to improve fatigue life, wear resistance, and surface strength

2. Aluminum Alloys

• Aerospace-grade and automotive aluminum (e.g., 2024, 7075)

• Sensitive to over-peening; requires softer media (like glass or ceramic)

• Benefits include weight savings with retained strength

3. Titanium Alloys

• Used in aerospace and medical implants

• Requires non-contaminating media (like ceramic beads)

• Shot peening enhances fatigue resistance without affecting biocompatibility

4. Nickel-Based Superalloys

• Inconel, Hastelloy, and similar high-temperature alloys

• Used in turbine blades, jet engines, and power plants

• Peening helps maintain structural integrity under thermal cycling

5. Magnesium Alloys

• Lightweight materials for aerospace and electronics

• Require very controlled peening parameters to avoid damage

• Benefit from increased surface toughness and corrosion resistance

Matching Media to Material: Why It Matters

Choosing the right media is about balancing hardness, size, and impact energy with the material being treated. Too hard a media on a soft material can cause pitting or cracking. Too soft a media on a hard material won’t induce enough stress to be effective.

For example:

Workpiece Material	Recommended Media	Reason
Hardened Steel	Cast steel or cut wire shot	Matches toughness, adds deep compressive stress
Aluminum Alloys	Glass beads, aluminum shot	Prevents surface overwork or distortion
Titanium	Ceramic beads	Non-contaminating, precise stress control
Stainless Steel	Stainless cut wire shot	Avoids cross-contamination and corrosion issues

FAQs: Shot Peening Materials

Can non-metallic parts be shot peened?

Generally, no. Shot peening is designed for metals and hard alloys. Plastics or composites may be damaged unless specially formulated and paired with soft media.

Is it possible to recycle shot peening media?

Yes. Steel and ceramic media can be recycled hundreds of times. Media lifespan depends on hardness, cleanliness, and the abrasiveness of the treated part.

What happens if the wrong media is used?

Improper media can damage the part, reduce fatigue strength, or cause contamination (e.g., rust on stainless steel). Media selection is critical for quality and safety.

How do I know what media to use for my application?

Engineers determine media based on material type, part geometry, fatigue requirements, and industry standards (like SAE J442 or AMS 2430).

Conclusion: The Right Material Makes All the Difference

In shot peening, both the media and the material being treated must be carefully selected to achieve optimal results. Whether you're working with hardened steel gears or lightweight aluminum components, the choice of shot—its hardness, shape, and composition—directly influences performance, durability, and safety. 

With the right pairing, shot peening becomes one of the most cost-effective and powerful tools for extending the life and reliability of critical components.

📞 Call to Action

➡️ Get a Quote Today

➡️ Learn More about Our Shot Peening Capabilities