# Spindle Hours

Canonical URL: https://fundmyequipment.com/learn/glossary/spindle-hours/
Last modified: 2026-05-29T19:39:17+00:00
Type: efin_glossary

## Summary

Hours CNC spindle has been actively cutting. Used in CNC valuation.

## Content

Spindle hours are the total runtime hours of a CNC machine's cutting spindle (the rotating tool-holder that performs the actual material removal). Spindle hours are the primary wear indicator for CNC equipment valuation, similar to how mileage or engine hours work for vehicles.
Why spindle hours matter

Wear indicator: spindle bearings, belt drives, and motor wear progress with hours
Useful life: typical CNC spindles last 15,000-30,000 hours before major rebuild
Resale value: lower spindle hours mean higher resale value
Lender confidence: CNC financing decisions reference spindle hours

How to find spindle hours
Most CNC controls (Fanuc, Siemens, Mitsubishi, Heidenhain, Mazak) track spindle hours in the system parameters. The machine operator or service technician can pull the value:

Fanuc: typically under "Hour Meter" or "Maintenance" parameters
Siemens 840D: in the diagnostic data
Mazak: control-specific menu
Older controls: may require parameter dump or service-tech interrogation

Spindle hours vs power-on hours
Different metrics:

Power-on hours: total time the machine is energized (includes idle, setup, standby)
Spindle hours: only when the spindle is rotating
Cutting hours / "in-cycle" time: only when the machine is actively cutting material (most useful for wear)

Power-on hours can be much higher than spindle hours. A machine may sit powered-on for 8 hours/day but only cut for 4-5 hours. Both numbers matter; spindle hours are the better wear indicator.
Spindle rebuild
When a spindle reaches 15,000-25,000 hours, a precision rebuild is often warranted. Rebuilds cost $10,000-50,000 depending on machine and complexity. A rebuilt spindle can extend useful life by another 10,000-15,000 hours.
For equipment buyers

Always request spindle-hour reading from the seller (with documentation from the control panel)
Below 5,000 hours: like new
5,000-15,000 hours: standard used; expect normal wear
15,000-25,000 hours: aging; budget for potential rebuild
Above 25,000 hours: rebuild likely needed or already done