SPINDLES Contact Us About Your Specific Spindle Requirements Tool Post grinders are designed to use interchangeable spindles therefore care should be taken when choosing a spindle. You will want to select a spindle that most closely fits your particular application, because your choice will determine the grinding wheel size and RPM that can safely be used. We have the experience and training to guide you through the selection process; please contact us. 5X-350 - Standard external grinding spindle for the Series 57 5X-450 - For external grinding using diamond wheels 5N-309 - Three bearing internal grinding spindle with 21.83” OAL 5N-315 - Three bearing internal grinding spindle with 27.83” OAL 5T-200 - A versatile two bearing grinding spindle that can perform both external or internal grinding with optional inserts Optional Inserts for 5T-200 TX - For external grinding using 5” maximum diameter 3/8” bore wheels TN-15/8 - For internal grinding to a maximum depth of 1-5/8” TN-3 - For internal grinding to a maximum depth of 3” TN-4 - For internal grinding to a maximum depth of 4” TN-5 - For internal grinding to a maximum depth of 5” TN-6 - For internal grinding to a maximum depth of 6” TC - Collet type insert for internal grinding using 1/8” or 1/4” mounted wheels