What are the ANSI Chain Standards?
18th Jun 2024

From factory conveyors to farming equipment, power transmission roller chains play integral roles across countless mechanical systems. But with so many vital applications, how are chains standardized for interoperability? In the United States, it all comes down to compliance with ANSI standard roller chain.

  • ANSI B29.1 regulates 14 roller chain sizes
  • Numbering system indicates chain pitch
  • Standards enable interchangeability between manufacturers
  • Compatibility with sprockets is ensured through precision

When you see the identifier “ANSI” on a chain, it means strict dimensional and performance criteria have been met per the American National Standards Institute. This ensures proper function, safety, and part interchangeability – vital factors when systems rely on chains day in and day out.

The 14 Standard Chain Sizes

The most common power transmission chains regulated under ANSI B29.1 consist of alternating inner and outer plates with bushings and rollers. These roller chains come in 14 standard sizes:[1

  • ANSI 25 chain
  • ANSI 35 chain
  • ANSI 41 chain
  • ANSI 40 chain
  • ANSI 50 chain
  • ANSI 60 chain
  • ANSI 80 chain
  • ANSI 100 chain
  • ANSI 120 chain
  • ANSI 140 chain
  • ANSI 160 chain
  • ANSI 180 chain
  • ANSI 200 chain
  • ANSI 240 chain

The sizing number correlates to the chain’s pitch, or distance between roller centers. Basically, take the left-most digit(s), and multiply by 0.375 inches to get the pitch in inches. For example, the #100 chain has a 1.00″ pitch. Metric pitches are also standardized.

Number 41 is a narrower relation to the #40 size. And chains ending in “5” instead of zero have no rollers, just bushings – known as bushing chains. They serve light-duty applications.

Other Compliance Factors

Along with pitch, ANSI also governs roller diameters, plate thicknesses, link lengths, and the critical clearances between rollers and sprockets during meshing. Tolerances are tight – just a few thousandths of an inch – to maintain proper articulation and load-carrying capacity.

The standards also regulate material properties and hardness to balance roller chain strength and fatigue life with sprocket wear rate. This ensures reliable, safe operation even in challenging environments.

Why Standards Matter

By conforming to ANSI B29.1, manufacturers align their roller chains to work interchangeably with sprockets from other vendors also meeting ANSI specifications. This compatibility ensures strong value chain development and flexibility.

Engineers can source chains from various suppliers while trusting alignment with sprockets designed around these standards. It simplifies integration and repairs. Branding chains as “ANSI Compliant” declares adherence, further reinforcing quality.

Of course, standards evolve over time to allow innovation. But at their core, the ANSI chain specifications eliminate guesswork and enable total drive system optimization. They form a “universal language” – a foundation for endless power transmission applications.

About Universal Chain

Founded in 1970, Universal Chain has manufactured premium power transmission chains for nearly a century. As a fully integrated chain facility, Universal controls quality from melt to finished product across their ISO 9001 and 14001 certified plants.

Universal’s vertical integration enables high production capacity – over 15,000 tons annually – alongside tremendous flexibility. Their tooling and machines adapt quickly to produce standard and custom chain solutions, from engineering samples to high-volume requests.

Beyond exceptional quality, inventory and service, Universal builds trust through chain expertise nurtured over decades. Their engineering team provides technical consultation and product development support tailored exactly to your application challenges. And their field sales staff keeps a pulse on emerging customer needs.


From industrial lifts to agricultural implements, equipment reliability often starts with the simple roller chain. When sourcing this vital component, the ANSI stamp signals quality, safety and dimensional alignment per the world’s foremost standards organization. With ANSI compliance, engineers know they’re getting a chain purpose-built to enable their mechanical designs.

When uptime matters, choose the smoother operation and lasting durability only possible from an intelligently engineered, meticulously manufactured chain. Discover why the world’s leading OEMs trust Universal Chain to drive their equipment – request a custom quote today.

Article Sources
The Universal Chain uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Our commitment to accuracy and reliability ensures that readers receive well-researched information they can trust.