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A smooth (round) rubber belt with a 3.18 mm (1/8″) cross-section diameter and 63.5 mm (2.5″) inside diameter. The elastic rubber construction provides excellent grip on pulleys and can withstand temperatures from −37 °C to +121 °C (−35 °F to +250 °F) with a Shore A70 durometer hardness.

Key Features

  • 3.18 mm (1/8″) Cross-Section – Fits Actobotics and compatible smooth pulleys
  • 63.5 mm (2.5″) Inside Diameter – Unstretched belt circumference
  • Shore A70 Hardness – Flexible rubber with good grip characteristics
  • 12–26% Stretch Factor – Adjustable tension depending on pulley spacing
  • Wide Temperature Range – −37 °C to +121 °C

Ideal For

  • Actobotics and robotics drive systems
  • Follow-focus mechanisms
  • Linear drives and XY tables
  • 90° drive configurations
  • Robot tracks and battery hold-downs
Tip: A lower stretch factor (12%) applies less side-load to axles and creates less friction. A higher stretch factor (up to 26%) increases resistance to belt deflection but adds more side-load.

Package Contents

  • 1× Smooth Belt, 3.18 mm × 63.5 mm ID

The Smooth Belt - 1/8D (2.5 ID) appears in the following collections:

SKU SF-ROB-12370