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Formsprag Model HPI Indexing Clutch for Speaker Grill Punch Press Feed Drive

A manufacturer of automotive speaker grills needed a longer lasting replacement clutch solution for use on the feed drives of their punch presses that operate at 1,400 strokes/min. The machine’s original clutches were wearing out prematurely causing frequent periods of production downtime.

Formsprag HPI indexing clutches, with a 92 million cycle life, were selected to meet the application challenge. HPI clutches are especially-designed to provide the maximum in dependable, uniform, long life performance in medium- to heavy-duty indexing applications.

The clutches are installed on the material feed drives of the punch press machines to provide a uniform, incremental rotation of the feed rollers with each stroke of the press ram. The reciprocating motion of a gear rack is translated into specific and uniform motion by the HPI clutch, advancing the correct amount of material for the next punch stroke.

All HPI models contain PCE sprags with Formchrome® and Formsprag “Free-action” retainers. The clutches mount on a through-shaft, with the inner race driven by a key. The key fit was very tight for this particular application. HPI 400 models have a torque capacity of 300 lb.ft. (407 Nm) and a maximum 2,800 RPM overrunning speed and feature oil lubrication lip seals.

Formsprag HPI Indexing Clutch


  • Custom sprag design
  • Sprags feature patented Formchrome® surface hardening
  • 300 lb.ft. (407 Nm) torque capacity
  • 2,800 RPM max overrunning speed
  • Inner race key

Contact Information

Formsprag Clutch
23601 Hoover Rd.
Warren, MI 48089 - USA
Toll Free: 1-800-348-0881 (Press #1)
Phone: 586-758-5000
Fax: 586-758-5204

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