OEM vs Aftermarket Spare Parts: What’s the Right Choice?

What Are OEM and Aftermarket Parts?

OEM (Original Equipment Manufacturer) parts are produced by the same company that made the original components for your equipment. Aftermarket parts are made by third parties and are designed to be compatible, but not always identical in quality or performance.

Key Differences Between OEM and Aftermarket

Design and Specifications

OEM parts follow the exact design, materials, and tolerances specified by the equipment manufacturer. Aftermarket parts may vary slightly, which can affect fit, performance, or compliance.

Warranty and Risk

Using OEM parts usually maintains your equipment’s warranty and compliance. Aftermarket alternatives may void warranty terms or introduce failure risks.

Documentation and Certification

OEMs provide certificates (CE, ISO, CoC) and full traceability. Many aftermarket suppliers lack proper documentation, especially for regulated industries.

Availability and Lead Times

OEM parts are often available with consistent lead times. Aftermarket options may be faster or cheaper, but availability can be unpredictable.

When You Can Consider Aftermarket Parts

• For non-critical equipment or backup systems
• When cost is the highest priority
• When the part is certified and tested independently

If you're not sure how to evaluate OEM parts, check our guide on choosing the right OEM parts.

Why OEM Is Still the Safer Long-Term Choice

In many industries — especially where safety, compliance, and uptime are key — OEM parts are the only reliable solution. The risk of using substandard parts far outweighs the cost savings.

Total Cost of Ownership (TCO)

OEM parts often last longer, reduce downtime, and come with support — lowering your TCO despite a higher upfront price.

How Stern Company Helps You Choose

• Verified OEM sourcing across multiple brands
• Guidance on when OEM is critical — and when alternatives are acceptable
• Fast global delivery and support with documentation