Tapered Propeller Shaft Couplings

18 Mar.,2023


The company has a group of cooperation teams engaged in the Cardan Shafts Manufacturer industry for many years, with dedication, innovation spirit and service awareness, and has established a sound quality control and management system to ensure product quality.


RE Thomas Marine Hardware manufactures tapered propeller shaft couplings for marine propeller shafts.  Our tapered couplings are available to fit most marine transmission systems including Twin Disc, ZF, Allison, Hurth, Borg Warner, and Capital.

Tapered marine couplings are superior to split couplings and solid couplings due to their improved alignment characteristics and rigidity.  They’re also easier to remove and reattach while maintaining their original shaft alignment.  Tapered couplings are safer, more reliable, and ultimately a better investment for your boat.

Diagram of a Tapered Shaft Coupling:

Our tapered coupling retention method utilizes a simple (but effective) single locking nut design. The shaft is pulled into the coupling body and washer by torquing the locking nut into the machined end of the propeller shaft. There are three taped holes for installing the machined Allen-head keeper pin (machine screw). Install the keeper pin in the tapped hole that offers the best fit to help prevent the nut from backing off.

Avoid Exposed Shaft Taper:

Have you ever noticed a little bit of exposed taper on a propeller shaft?  Often times, propeller shaft shops lack the expertise or machinery to properly fit the tapered coupling to the propeller shaft.  This can result in the the shaft not fully entering the tapered bore of the coupling.  The diagram below illustrates this common issue with tapered couplings.

For example, you might have a 2″ diameter propeller shaft but it may only seat in the coupling up to a diameter of 1 3/4″ leaving a 1/4″ of shaft diameter exposed (see illustration above). This exposed shaft taper effectively weakens your propeller shaft the strength of a 1 3/4″ shaft.

Our precision machined tapered couplings are designed to work with our exclusive double tapered shaft system.  Please contact us with any questions on converting your propeller shaft to a double tapered shaft system.

Marine Machine Shop:

RE Thomas Marine Hardware is a full service marine machine shop offering custom length propeller shafts.  Unlike many propeller shaft shops, RE Thomas does all cutting, tapering, and shaft keying on site.  This allows us to offer both single taper propeller shafts, and double tapered shafts, with a quick turnaround time.

In addition to our full line of dripless shaft seals, shaft bearing housings, and rudder ports, we carry a full inventory of Aqualoy© 22 grade propeller shafts. We also offer free professional delivery of shafts throughout the state of Maine and into New Hampshire.

Give us a call today for all your propeller shaft and marine hardware needs.


With high quality products and considerate service, we will work together with you to enhance your business and improve the efficiency. Please don't hesitate to contact us to get more details of Cardan Shafts Manufacturer.