From the menus, click Tools > Options. Under NC Defaults, click Tools. Notice the new settings Use Gage Length for all Milling Operations and Use Gage Length for all Lathe Operations. These settings typically apply only to 4- and 5-Axis NC machines.
Use Gage Length for all Milling Operations
If checked, milling operations output the Z Gage Length value from the Tool Information tab. If your post is written to apply the Z Gage Length value, the value will be output to the NC code. If not checked, the Z Gage Length value will be grayed out, and the operation will not output the value.
Use Gage Length for all Lathe Operations
This setting works like Use Gage Length for all Milling Operations, but applies to Lathe Operations and includes the X Gage Length value.