Allied Machinery, Leeds, United Kingdom Page 9.

Truegrip Expanding Spindles - Process.. If your spindles/s are serviceable (correct size, undamaged and perfectly straight), we cut a small groove to insert a seal and a key into the shaft. Note - it is not necessary to dismantle your spindle/bearings etc. Once that is done we install special parts which restores your spindle to its original size. If you have some, you can still fit your old hydro type blocks or standard void bore blocks. They will not harm the new shaft. Fittings are installed to allow you to use a standard Abnox type grease gun to pressurise the shaft. The thread (if present) is preserved. We need to know where you want the expanding portion of the shaft, to be placed along the shaft. The expanding section is normally 100mm long. We would normally start 10mm from the cutterblock journal shoulder, unless you tell us otherwise. We can put multiple expanding sections in the shaft, but it is normally unnecessary, unless you have extremely large torque transmission requirements. Demonstration spindles can be viewed at our works/showroom