Services · Shot peening
Controlled Shot Peening Services
Review the process parameters, application scope, required input data and feasibility for a specific component.
Maximize fatigue resistance and component longevity with precision controlled shot peening from SP Center,
delivering certified surface enhancements for high-stress industrial applications.
What is Shot Peening & How Does it Work?
Shot peening is a cold-working process used to prevent fatigue failures, stress corrosion cracking, and galling in metallic components. Unlike cosmetic surface finishing, controlled shot peening is a mechanical treatment engineered to alter the physical properties of the metal’s surface layer.
SP Center performs controlled shot peening in accordance with the customer’s drawing and specification. The process introduces beneficial compressive residual stresses into the surface layer and improves fatigue resistance. Feasibility for the specified material, geometry and required intensity is confirmed before quotation.
In controlled shot peening, a stream of selected media is directed at the component surface using air pressure or centrifugal force. Unlike shot blasting, the purpose is not surface cleaning but controlled surface strengthening. The process controls media properties and condition, intensity, the saturation curve where required by the specification, coverage in accordance with customer documentation, and parameters such as media flow, pressure or machine speed, component positioning and exposure time.
Media are selected according to the material, component geometry, required intensity, coverage and customer specification.
Media used:
- Cast steel shot
- Stainless steel shot
- Conditioned cut wire shot
- Glass beads — Glass Bead Peening
- Ceramic beads — Ceramic Bead Peening
Shot peening is most commonly applied to:
- Springs
- Gears
- Torsion bars
- Turbine components
- Crankshafts
- Connecting rods
- Drive shafts
- Brackets and structural elements
The Physics of Compressive Residual Stress & Peening Process
Controlled shot peening creates localized plastic deformation in a metal surface through repeated impacts from spherical media. The affected layer tends to expand, but the underlying elastic core restrains that expansion, leaving a continuous layer of compressive residual stress in the surface layer after treatment.
Compressive residual stresses introduced by shot peening neutralize operational tension, delay fatigue crack initiation, and slow crack growth under cyclic loading. The effect depends on the material, component geometry, initial surface condition, process parameters, and service loads. Surface appearance alone cannot establish the resulting fatigue performance of a specific component.
Shot peening control treats intensity and coverage as separate requirements. Almen strips are used to determine and verify process intensity; they do not directly measure residual stress in the component. Coverage describes how much of the treated surface bears impact indentations. Meeting the specified intensity does not, by itself, confirm the required coverage.
At SP Center, the customer’s drawing and specification define the scope of controlled shot peening. Before preparing a quotation, we assess access to the areas to be treated, protection of excluded surfaces and feasibility for the material and geometry. Media selection, inspection methods and process documentation are agreed for the individual project.
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Process Control Parameters: Intensity, Coverage & Almen Strips
Almen Intensity & Almen Strips: Process intensity is measured using Almen strips—standardized thin strips of spring steel (Types N, A, or C) mounted to fixture blocks and exposed to the blast stream. The residual stress creates arc height curvature in the strip. Arc height measurement on an Almen gauge defines the Almen intensity, ensuring precise kinetic energy transfer to the target workpiece.
Shot Peening Coverage: Coverage represents the percentage of the component surface occupied by peening dimples. High-reliability engineering requires full visual coverage (typically 100% to 200%), validated via high-magnification optical inspection or fluorescent tracer dyes under ultraviolet light.
Key Benefits & Applications
Controlled shot peening extends the operational lifespan of metallic parts by up to 1,000%, depending on material selection, heat treatment, and load dynamics.
Core Industry Applications
- Shot Peening Springs: Compression, extension, and suspension springs suffer intense cyclic stress. Peening eliminates surface micro-imperfections, preventing early spring failure under high-frequency operation.
- Shot Peening Gears: Transmission and power-train gears undergo heavy bending stresses at the tooth root and contact fatigue at the flank. Peening increases tooth bending strength and contact fatigue endurance.
- Shot Peening Turbine Blades: Jet engine and power generator turbine blades operate under elevated temperatures and centrifugal forces. Peening mitigates fretting fatigue and thermal cycle degradation.
- Shot Peening Aircraft Parts: Critical flight hardware, including landing gear assemblies, wing spars, structural bulkheads, and rotor hubs, require certified shot peening to prevent catastrophic failure from fatigue and stress corrosion.
Controlled shot peening supplier for European manufacturers
What information is needed for a shot peening quotation?
Send your drawing and specification, or describe the component and share the information already available while you complete the documentation. Our engineer will help organise the requirements, identify the inputs needed and plan process preparation.
| Information | Why it matters | Can it follow later? |
|---|---|---|
| Drawing and shot peening specification | Defines areas, exclusions and acceptance criteria | Preferably included at RFQ |
| Material and component condition | Affects media and process feasibility | Required before approval |
| Required Almen intensity and coverage | Defines the controlled process window | Required if stated by the drawing |
| Quantity and production phase | Separates samples, qualification and series planning | Estimate accepted at RFQ |
| FAI, PPAP or customer documentation | Defines the qualification and release package | Scope can be agreed after review |
| Requested delivery date and destination | Supports capacity and logistics review | Required before order confirmation |
How does SP Center control the shot peening process?
SP Center controls the process variables required by the drawing, specification and agreed project scope. The current service description includes media condition, Almen intensity, saturation curve when required, coverage, media flow or pressure, machine speed, component positioning and exposure time. Masking and tooling are defined when the component requires protected areas.
SP Center uses cast steel shot, stainless steel shot, conditioned cut wire, glass beads and ceramic beads. The final medium is selected for the material, geometry, required intensity, coverage and specification. We select the medium for the component and the drawing and specification requirements as part of process development.
Which components can be reviewed for controlled shot peening?
SP Center’s current service scope lists springs, gears, torsion bars, turbine components, crankshafts, connecting rods, drive shafts and structural parts as common applications. Listing a component does not confirm feasibility for every material or geometry. The drawing and specification control the decision.
What qualification and quality evidence is available?
SP Center can plan qualification around trials, sample parts, PPAP or FAI requirements and residual stress measurements when required. The agreed documentation scope can include process flow, control plan, PFMEA linkage, traceability, inspection points and release records. XRD residual stress measurement is supported in cooperation with a specialised laboratory; the scope and chain of custody must be agreed for the project.
SP Center holds BSI certificate FM 829811 for EN 9100:2018 and ISO 9001:2015. The published certificate scope is “Shot peening services for the aerospace, automotive, medical and general industries” and the certificate is shown as valid until 7 October 2028. Certificate validity, customer approvals and project-specific requirements must be checked before order confirmation.
When is an external shot peening supplier the right choice?
| Situation | External specialist is useful when | Keep or develop in-house when |
|---|---|---|
| New component | qualification capability and documentation are needed before series | stable high volume justifies dedicated equipment and staff |
| Capacity constraint | a controlled alternate route reduces single-source risk | existing capacity is sufficient and qualified |
| Complex quality package | the supplier can support agreed FAI, PPAP and traceability | the organisation already owns the qualified process and evidence |
| Low or variable volume | outsourcing avoids underused dedicated equipment | predictable volume supports total-cost investment |
| Independent verification | external process and laboratory evidence are required | internal approvals already cover the full requirement |
We help compare delivery models in terms of cost, logistics, available capacity and schedule. The quotation covers the agreed process and documentation scope, giving you a clear view of the proposed cooperation.
What happens after the RFQ is sent?
- SP Center checks whether the drawing, specification and project information are complete enough for review.
- A process engineer proposes an implementation plan, defines the scope of trials and organises the documentation needed to prepare for production.
- Capacity, testing, documentation and logistics are reviewed before quotation.
- The quotation and project plan clearly state the agreed process scope, parameters, documentation and approval steps.
Frequently asked questions about outsourcing shot peening in Europe
Does SP Center accept a drawing before all process parameters are known?
Yes. Send your drawing and the information you already have. Our process engineer will help clarify the requirements and prepare the next steps, using the applicable drawing, specification and customer requirements.
Can the project include PPAP or FAI?
PPAP or FAI can be included when required and agreed. The required forms, samples, measurements, approval route and customer-specific requirements must be defined during review.
How are XRD residual stress measurements arranged?
We arrange XRD residual stress measurements in cooperation with a specialised laboratory. Before testing, we agree the measurement scope, method, sample identification and reporting requirements with you.
How does SP Center support the documentation for component qualification?
We provide current certificates with their scopes and agree the process records and qualification documents needed for your component. Project-specific approval requirements are included in the plan from the outset.
Send your drawing and requirements
Describe your project using the information you have. A process engineer will help clarify the requirements and propose the next step. Include the drawing, specification, material, quantity, required delivery date and documentation expectations when available.
Second-source supply
Qualifying an alternate shot peening supplier?
See how we support the introduction of a second source: from documentation review and trial preparation to agreed FAI or PPAP records and process preparation for production.