Rosta SEF15 Tensioner device is not only a modern engineering marvel but is also a maintenance-free tensioning device that is utilized throughout the world for the various belt and roller chain applications. The 61030028 SEF-15 front mounting tensioner serves three purposes; a torsional spring, a pivot bearing, and an anti-vibration mount. The true advantages of a ROSTA SEF15 tensioner versus look-alikes are the patented specially engineered material that is within every tensioning device made by ROSTA, cost advantage, overall durability, and solid performance on high productivity productions lines. The front mounting style tensioner serves its purpose in applications with blind-hole frames, for over 45-years ROSTA has produced some of the highest quality and longest-lasting dampening and tensioning devices on the market! For more information or to get a quote on the SEF15 tensioner please contact us and we will be happy to assist you!

SEF15 Tensioner Dimensions

• Tensioner Type: SEF15
• Article Number: 61030028
• Dimension (D): 1.77"
• Dimension (E): 2.52" (+0.039 / -0.020)
• Dimension (G): 0.20"
• Dimension (H): M6
• Dimension (J1): 3.94"
• Dimension (J2): 3.15"
• Dimension (K): 0.98"
• Dimension (L): 4.43"
• Dimension (M): 0.47"
• Dimension (N): 1.18"
• Dimension (O): 0.31"
• Dimension (P): 0.33"
• Dimension (R): 0.39"
• Dimension (T): 0.53"
• Dimension (U): 0.82"
• Weight: 0.9 LBS
• Normal Temperature Range: -40°F to +176°F

Tensioning Force Table:

Tightening Torque Table:

ROSTA SEF15 Tensioner Technology

At the core of every ROSTA tensioner lies a special rubber compound that conforms to ISO 14001 with a unique ability to provide the consistent tensioning force with minimal impairment to the material its self. ROSTA is the only company capable of producing this specific material, this is why no "interchange" can withstand the same life-span as a ROSTA tensioner.

To find out additional information on the technology click here!

SEF-15 Mounting Instructions

Tensioner Mounting

Tighten the flange screw slightly. Grip the housing with flat-wrench and set needful pre-tension by rotating the housing in the required direction. Tighten the central screw according to the above mentioned tightening moment MA. Position flat-wrench close by the flange-bottom.

Z-configuration of Sprockets or Riders

If there is the need to install sprockets, riders or rollers on the outer arm-side of the tensioner, then the distance "Z" should be as little as possible to avoid misalignment in element parallelism. Furthermore, the pre-tension force should not exceed 50% of the capacity = max. the pre-tension angle of ~ 20°.

Use of SE-B Boomerang Tensioners

In very long chain and belt drives it was recommendable to install on the slack-side several tensioners, in order to compensate for occurring elongation. The "Boomerang" with its bent double-arm equipped with two chain sprockets or a combination of grooved pulley and flat-roller (belt-drives) offers a triple-compensation of chain and belt elongations, due to S-shape contact-arc.