HSD Replacement Spindle

HSD Replacement spindle. 

These spindles are direct replacement spindles for HSD models 915, 919 and 929. They are designed to be plug and play solution with no modifications needed to replace your HSD spindle. The electrical and pneumatic connectors are the same. No need to replace cables or tubing. The distance and center height of the shaft is the same as well as C-Axis bolt patterns.

In order to quote the correct spindle, we need the following information.

  1. The S1 power rating. Please note, these spindles use a S1 and S6 rating. This can be found on the cover of the terminal box.
  2. The voltage of the spindle and the number of poles (found on the cover of the terminal box).
  3. Identify if it is a long nose or short nose.
  4. Identify if it is HSK or ISO 30 tooling

That’s it. We can help verify this information with a picture of the terminal box cover and the nose of the spindle.

Technical Features:

Dimensions and Mounting

These spindles are designed to have overall dimensions to be equal or less than the equivalent HSD spindle. All critical dimensions are the same such as the position and center height of the nose of the spindle, location of connections and the mounting points.

The front bearing support is the same diameter and length. The C-axis bolt circle is the same as well as electrical connections.

It uses the same T-slot system as the HSD and all key slots are identical.





Pneumatic Connections

Same size fittings as the HSD and mounted in the same location.

Operates with the same air pressure and flow requirements.

Electrical Connections

Uses the same connector as the HSD. No need to make a new harness.

Power and signal connections use the same voltage. The pin-outs are the same and will function just like the HSD.

The electrical connection is located in the same position. The cables will fit perfectly with no stretching or extra slack.

Air Cylinder

The are a few variations of these in the industry. The HSD uses a spring return for the cylinder and ports the other functions such as pressurization thru the main connection ports. The new spindle cylinder is designed to operate exactly like the HSD.


The fan is 220 volts. The removal and operation is the same. The fan connection point is the same as the HSD.

C-Axis Connections

The spindle uses the same electrical connector. The mounting points are the same, including the diameter and length of the bearing support.

Sensor Functionality

Sensors are easier to adjust and simplified. HSD uses two sensors for HSK versions.  Also, includes the S3 sensor as standard equipment. This is optional on the HSD.

S1 – Tool holder locked properly

S2 – Tool holder unlocked (Open chuck)

S3 – Shaft rotation

Push Button

Push button on the side of the terminal box. It has the same functionality as the HSD.


Better balancing

Balancing screws located on the exterior of the spindle as opposed to the internal location if the HSD.

This is easier to balance, making for less expensive repairs. Also, the HSD has balancing screws located under the stator windings. If a set screw comes loose, it will damage the stator resulting in a costly repair.

Shielded Sensor Cables

Signal cables are shielded. HSD signal cables are not shielded.


Sensors are easier to adjust and simplified. HSD uses two sensors for HSK versions. This spindle uses one. Includes the S3 sensor as standard equipment. This is optional on the HSD.

Easier Cartridge Replacement

The HSD requires more effort to replace the cartridge. You must remove the fan shroud, actuator and drawbar retaining clips. This involves disconnecting the sensors and reassembling with heat shrink

The cartridge on the replacement spindle is much easier. Just from remove the front bolts in the front (same as HSD) and remove the cartridge. Reinstall the new cartridge and re-install the screws. That’s it. No need to remove the rear components.

Note: If the spindle has an encoder, it will be necessary to remove the rear components.


Encoder: TTL or 1 Vpp. (not available on HSD spindles).

S5 sensors (piston back).

Connectors are available with or without cables.