D3840 V-Belt — Brand Comparison

Compare the D3840 V-belt across Gates, Continental, Optibelt, Dayco, and Bando.

Equivalent Part Numbers

BrandPart NumberProduct LineProfileLengthWidthPrice
GatesD3840D
ContinentalD3840StandardD
OptibeltD3840StandardD
DaycoD3840StandardD
BandoD3840StandardD

Verification

All brands produce the D3840 to the same industry-standard dimensions
Cross-section profile (D) is standardized across manufacturers
Belt length is identical — direct drop-in replacement
Pulley groove compatibility confirmed (same V-angle)

Why Belt Part Numbers Are the Same Across Brands

Unlike bearings (where SKF uses “2RS1” and NSK uses “DDU” for the same seal type), V-belt manufacturers all use the same industry-standard naming system. An A68 from Gates is the same dimensions as an A68 from Continental, Optibelt, Dayco, or Bando.

The letter designates the cross-section profile (A, B, C for classical; 3V, 5V for narrow) and the number designates the length. This standardization is based on RMA/MPTA and ISO standards that all manufacturers follow.

The differences between brands are in rubber compound, cord construction, and manufacturing quality — which affect belt life and performance under extreme conditions. For standard applications, all brands are fully interchangeable.

Frequently Asked Questions

Can I replace a Gates D3840 with a Dayco D3840?

Yes. Both are manufactured to the same industry-standard dimensions. They are direct drop-in replacements for each other.

Which brand of D3840 belt is best?

Gates is generally considered the premium brand for industrial V-belts. Continental and Optibelt are also high-quality European manufacturers. Dayco is strong in automotive applications. Bando is popular in Asia. For standard applications, any brand will perform well.

What's the difference between D3840 and DX3840?

The “X” suffix (e.g., AX68 vs A68) indicates a notched/cogged construction. Notched belts run cooler and are more flexible, allowing use on smaller pulleys. Same length and width — different internal construction.