Lathe inspection checklist (before start of work, daily, weekly, monthly, yearly) and maintenance

Daily (including before start of shift)

Check the lubricating oil levelCommonBefore start of shiftWhat to checkEngine lathes: oil gauges on the headstock, feed gearbox, and apron. CNC lathes: oil gauges on the automatic lubrication tank, hydraulic tank, etc.GuidelineWithin the range of the oil gauge. Haas's manual lathe says to top up when the level falls below the center line of the gauge, filling to about 80%If the oil runs out, gears, bearings, and ways seize or wear quickly. Hardinge puts a caution in its manual to check the oil level before operation. Colchester's 13-inch lathe manual says to check the oil level in the headstock and feed gearbox "once a week" (the interval differs by model). Okuma (US), Makino, and Takisawa also say to check the amount of way oil daily (before start of work). Top up with the power off, and do not remove the filter in the filler port. Haas's maintenance table for CNC lathes says monthly^{[1][2][3][4][5][6][7]}
Read the oil level after stopping the machineGeneral-purposeBefore start of shiftWhat to checkOil gauges on the headstock and feed gearboxGuidelineRead after stopping, once the oil has settled downReading while it is running makes the level look low and leads to overfilling. Overfilling causes heat and oil leaks^[8](1 source, for reference)
Check that the headstock oil is circulatingGeneral-purposeBefore start of shiftWhat to checkWindow or oil gauge for viewing the oil flow in the headstockGuidelineAfter turning on the power, oil should be flowing in the headstock (Haas)The headstock lubricates the gears and bearings by oil bath and circulation. Colchester says lubrication determines the machine's accuracy and life, and strongly calls for daily care^[1][8]
Check the coolant (cutting fluid) levelCommonBefore start of shiftWhat to checkLevel gauge on the coolant tankGuidelineCheck daily at the start of operation. If the machine is used more than 8 hours a day, check every 8 hours. Fill to H when the pump is stopped and to MAX when it is delivering. Below L, the coolant system does not work properlyWith low fluid, the pump sucks air and no coolant comes out^[2][7][9]
Check that safety devices, covers, and doors workCommonBefore start of shiftWhat to checkDoor interlocks, chuck guard, each coverGuidelineAll covers and doors operate properly and safety devices are enabled. Never disable a safety deviceA cover left off after maintenance or a faulty interlock leads directly to an accident^[2][3][10]
Check the location of the emergency stop buttonCommonBefore start of shiftWhat to checkEmergency stop button on the operator panelGuidelineIt must be within immediate reachSo the machine can be stopped at once in an emergency^[10][3]
Check the power cable sheath and the area around moving partsNCBefore start of shiftWhat to checkPower cable, areas near moving parts such as the chip conveyorGuidelineNo damage to the sheath. No obstacles near moving partsPrevents electric shock and entanglement in or collision with moving parts^[10](1 source, for reference)
Warm up the machineNCBefore start of shiftWhat to checkSpindle and feed axesGuidelineWarm up a machine that has been stopped for 8 hours or more before machining (Hurco)Thermal displacement of the spindle changes greatly both while spinning and while stopped, and affects machining accuracy (Okuma)^[2][11][12]
Check the mounting of chucks, tools, and workpiecesCommonBefore start of shiftWhat to checkChuck, collet, turretGuidelineCheck that workholding devices mounted on the spindle, such as the chuck, are securely attached. Tools are tight. The chuck key (wrench) has been removed. For a machine that has been stopped for a while, recheck the setup and workpiece clampingInsufficient tightening or a forgotten item leads to parts being thrown when the spindle turns^[3][13]
Check the air pressure drop when the turret rotatesNCBefore start of shiftWhat to checkPressure gauge on the air regulatorGuidelineIn Haas's example, if the gauge does not drop by 10 psi (0.70 bar) or more during a tool change (turret indexing), pressure and flow are sufficientInsufficient air pressure or flow causes turret clamp/unclamp failure. Water and dirt in the air cause cylinders and solenoid valves to malfunction (Makino)^[14][15]
Check the lever positions before startingGeneral-purposeBefore start of shiftWhat to checkSpindle speed dial, automatic feed lever, carriage lockGuidelineSet the speed to the lowest, the feed lever to neutral, and the carriage lock loosenedPrevents a crash the moment the machine starts. The South Bend and Haas manual lathe manuals are very similar in wording and structure (they seem to come from the same source)^[7][1]
Lubricate the ways (bed, saddle, cross slide) with the hand pumpGeneral-purposeDailyWhat to checkCarriage lubrication pump (one-shot)GuidelineHaas manual lathe: 3 times a day, 1 to 3 shots (including once before and once after operation). Hardinge: at least once a day, keeping the ways always wetProcedureAfter pumping, move the carriage and cross slide with the handwheels to spread the oil (Haas). On Hardinge's oiler, pull the plunger up and release it; do not push it downIf the oil film on the ways breaks, wear, seizure, and sticking feed result^[1][3]
Touch the ways to check there is a thin oil filmNCDailyWhat to checkWays (guideways) of each axisGuidelineAll axis ways have a thin layer of oilYou can notice a stopped automatic lubrication system before an alarm appears^[2](1 source, for reference)
Check the oil level and pressure of the hydraulic unitNCDailyWhat to checkHydraulic tank oil gauge, pressure gaugeGuidelineHurco's daily checks confirm it is set to 40 to 50 bar. The hydraulic pump setting on TM-series CNC lathes is 32 to 53.9 bar depending on the model, and the low-pressure stop setting is 15.0 kg/cm²Hydraulic pressure drives the chuck, turret, and tailstock. If the pressure falls, the chuck's gripping force drops. In the same Hurco document, checking the hydraulic tank oil level is "every 3 months" in the checklist and is also listed in the daily checks. The specified pressure is a per-model value. The example in an Okuma (US) article is 4.5 MPa, and the main pressure of the Takisawa TCN is 3.0 MPa (set at the factory). Yuken says to check the pressure daily^{[2][4][16][17]}
Check air pressure and drain waterNCDailyWhat to checkAir filter, regulator, lubricator (FRL)GuidelineAir pressure is at the specified value. The auto drain is workingAir is used for the chuck air blow, automatic doors, etc. If water collects, air equipment rusts^[2][18][15]
Grease the chuckNCDailyWhat to checkGrease nipples on the chuck's outer circumferenceGuidelineOnce a day is common. Howa: every 8 hours (every 4 hours if cutting fluid is constantly applied); SCHUNK: daily or every 16 hours (every shift or every 8 hours with heavy coolant use); Kitagawa: daily for types whose jaws slide; Hurco: dailyThe most common cause of chuck trouble is insufficient or unsuitable grease (Howa). Gripping force drops and the workpiece may come loose. Haas's maintenance schedule says to grease the jaws "weekly". See the chuck section for details. Okuma (US) also says daily (follow the chuck manufacturer's recommendation)^{[2][19][20][21][4][22][23]}
Remove chips and wipe down the machineCommonDailyWhat to checkWay covers, inside of doors, turret, chip conveyor screen (CNC); bed and carriage (engine lathe)GuidelineAt the end of work, remove chips and wipe unpainted machined surfaces with an oily clothAccumulated chips damage the way wipers and bellows and cause rust^[2][1][7][4]
Check the door window (polycarbonate) for scratches and cracksNCDailyWhat to checkMachine door windowGuidelineNo scratches, cracks, or deformation. Replace the window at least every 3 yearsThe window stops flying parts. Cutting oil, lubricating oil, and UV reduce impact resistance by up to 10% per year (Hurco). Haas and Okuma (US) also inspect and clean the window daily^[2][24][4]
Run the spindle and check for noise and vibrationCommonDailyWhat to checkSpindleGuidelineVary the speed from minimum to maximum; starting, stopping, and rotation should be smooth, with no abnormal noise or vibration (Hurco)Detects spindle bearing problems early. Hardinge asks that you not run the machine and report if there is abnormal heat, noise, smoke, or vibration^[2][3]
Move each axis through its full strokeNCDailyWhat to checkX and Z axes, limit switchesGuidelineMoves smoothly. Limit switches work at the correct positionsFinds sticking in the feed system (ball screws and ways) and faulty limit switches^[2](1 source, for reference)
Turn off the power and turn the spindle by handCommonDailyWhat to checkSpindleGuidelineTurns easilyFinds binding in the bearings or drive system^[2](1 source, for reference)
Oil the cross slide and tailstock oilers (ball oilers)General-purposeDailyWhat to checkTop of the cross slide (3 places), tailstock (2 places)Guideline2 to 3 drops daily or as neededProcedurePress the oiler ball with the tip of an oil can to clear dirt before adding oilPrevents wear on hand-moved sliding parts^[1](1 source, for reference)
Check the hydraulic oil temperatureNCDailyWhat to checkThermometer on the hydraulic unitGuidelineWithin the specification (example: tank oil temperature 5 to 60°C for a Yuken small hydraulic unit). It tends to rise in summerIf oil temperature or viscosity is out of range, pump noise and malfunction occur^[17](1 source, for reference)
Check for hydraulic leaks and pump noiseNCDailyWhat to checkHoses, fittings, pumpGuidelineNo leaks and no unusual sounds. Hoses are not rubbing against other parts, sharply bent, or twisted. Do not overtighten fittingsLeaks lower the oil level and interfere with pump operation^[17][25]
Run the variable-speed drive through its full speed rangeGeneral-purposeDailyWhat to checkVariable-speed drive (Hardinge HLV-H)GuidelineAt least once a day, through the full speed rangeTo lubricate the drive^[3](1 source, for reference)
Do not mix oils or add dirty oilCommonEvery time you lubricateWhat to checkFiller ports, oil cans (jugs)GuidelineUse only the specified oil, and do not mix different brands even of the same viscosity. Dedicate one can to each type of oil. If a non-specified oil gets in, flush the tank and pipingMixed oils of different viscosity or foreign matter reduce lubrication, damage the sliding surfaces, and make accuracy impossible to hold^[5][6][26]
Abnormalities that call for stopping immediatelyGeneral-purposeAlwaysWhat to checkFastening bolts, wiring, guards, emergency stop, brakes, headstock oil flow, cutting fluidGuidelineIf any one of these is found (loose bolts, damaged wiring, a guard that has come off, a faulty emergency stop, weakened braking, no headstock oil flow, no cutting fluid), stop, fix it, and then resumeTo prevent injury and keep the machine running normally^[7](1 source, for reference)

Weekly

Clean the coolant filterNCWhat to checkCoolant filter (on lathes, the coolant return filter daily)GuidelineWeekly or every 40 to 50 hoursClogging reduces the coolant flow and strains the pump^[2](1 source, for reference)
Clean and lubricate the lead screw, feed screw nut, and rackGeneral-purposeWhat to checkCarriage lead screw, feed screw nut, toothed rackGuidelineHardinge: at least once a week; Haas manual lathe: daily or as neededProcedureHaas says to clean the full length of the lead screw and then spread a thin film of oil over the threadsLeftover chips or dried oil wear the screw and rack and reduce feed accuracy^[3][1]
Check the automatic water drain of the air supply (lathe)NCWhat to checkFilter-regulator unitGuidelineThe auto drain is workingKeeps water from getting into air equipment^[2](1 source, for reference)
Remove chips from the coolant return (collector) under the spindleNCWhat to checkCoolant return line under the spindleGuidelineNot clogged with chipsIf clogged, coolant overflows toward the hydraulic unit, contaminating and foaming the hydraulic oil and overflowing the tank (Haas)^[24][25](1 source, for reference)
Clean the control cabinet air filterCommonWeekly to monthlyWhat to checkControl cabinet filter, inverter ventsGuidelineOkuma (US): weekly or every 40 hours; Haas and South Bend: monthlyTo let the air that cools the inside of the cabinet pass^[4][24][7]

Monthly

Top up the oil in the automatic lubrication tank and check the filterNCWhat to checkAutomatic lubrication device for the feed axes (ball screws and linear guides)GuidelineHurco checks the oil level and the filler port filter monthly; Haas checks the oil level monthly and tops upIf lubrication of the feed axes runs out, ball screws and ways wear and positioning accuracy drops. Hurco says to run the automatic lubrication manually after a long stop or after changing the oil^[2][24]
Check the turret oil levelNCWhat to checkOil gauge on the front of the turretGuidelineAt least half full. Fill with ISO VG100 to 150 oil (Hurco TM series)Lubrication of the turret indexing mechanism^[2](1 source, for reference)
Check the spindle gearbox oil levelNCWhat to checkOil gauge on the spindle gearboxGuidelineCheck the oil level monthly and change the oil once a year (Haas)Lubrication of the gearbox gears and bearings^[24](1 source, for reference)
Check the hydraulic tank oil levelNCWhat to checkOil gauge on the hydraulic tankGuidelineHaas: monthly; Hurco checklist: every 3 months (500 hours). For the Hurco TM series, fill with ISO VG32 to half of the gaugeIf the oil drops, the pump sucks air and pressure becomes unstable. Okuma (US) and Yuken: daily^{[24][2][4][17]}
Check wiring and hoses for cracks and loosenessNCWhat to checkConduits, connectors, and wiring on the outside of the machine; lubrication and hydraulic hosesGuidelineNo fraying, cracks, or looseness. Hurco: wiring monthly; Haas: lubrication hoses every 6 monthsPrevents oil leaks, broken wires, and electric shock^[2][24]
Check the mounting of limit switches and dogsNCWhat to checkLimit switches and dogs on each axisGuidelineNo damage or looseness (monthly or every 150 to 200 hours)Prevents accidents where an axis does not stop at the end of its stroke^[2](1 source, for reference)
Check way covers (bellows, telescopic covers) and wipersNCWhat to checkWay covers and wipers on each axisGuidelineHaas: inspect monthly and grease. Hurco: check daily for scratches, wear, and wiper damageIf covers or wipers are damaged, chips and coolant get into the ways and ball screws^[24][2]
Clean or replace the hydraulic oil filter and drain water from the tankNCWhat to checkHydraulic unit filter, drain at the bottom of the tankGuidelineIf it has a clogging indicator, follow the indicator (check weekly); without an indicator, about monthly. Drain water that has separated out when the machine is stopped, from the drainContaminated hydraulic oil causes pump failures and shortens life. Humidity in the air condenses and mixes into the hydraulic oil^[17](1 source, for reference)

3 months

Replace the coolant and filter, and clean the tankNCWhat to checkCoolant tank, filter, chip conveyorGuidelineEvery 3 months or 500 hours. Clean the chip conveyor at every coolant changeCoolant performance drops from spoilage and chip contamination. Full-change intervals: Okuma (US) every half year or 1000 hours, Takisawa 1000 hours, Haas every half year. For small tanks on engine lathes, South Bend says monthly^{[2][4][16][24]}
Replace air filters and drain water from the pipingNCWhat to checkFRL unit (filter-regulator-lubricator)GuidelineEvery 3 months or 500 hoursKeeps water and debris out of pneumatic equipment^[2](1 source, for reference)
Measure ground resistanceNCWhat to checkMachine groundingGuidelineEvery 3 months or 500 hours. Done by a qualified electricianPrevents electric shock and electrical malfunction^[2](1 source, for reference)

Every 6 months

Check chuck gripping accuracy and gripping forceNC500 hours to 6 monthsWhat to checkMaster workpiece, soft jaws bored on the machineGuidelineMeasure runout and gripping force and compare with the manual's values (Takisawa: every 500 hours; Haas: multi-point chuck inspection every 6 months)Too much gripping force distorts the workpiece or breaks the chuck; too little lets the workpiece fly out (Takisawa)^[16][24]
Check machine levelCommonWhat to checkBed (manual lathe); level base mounted on the turret (CNC)GuidelineHurco: check monthly for the first 6 months after installation, then every 6 months (1000 hours). See the Accuracy section for the detailed procedureIf the machine is out of level, the bed twists and accuracy suffers, e.g. parts turn tapered (Colchester). Takisawa places a precision level (sensitivity 0.02 mm/m) on the bed in the X and Z directions and centers the bubble with the jack bolts under the bed (every 1000 hours). Okuma (US): every 6 months or 1000 hours^{[2][8][27][4][16]}
Test spindle and feed-axis lubricationNCWhat to checkSpindle lubrication system, feed-axis lubrication systemGuidelineHaas runs the “Spindle Lube Test” and “Axis Lube Test” every 6 monthsConfirms that oil is actually reaching the points^[24](1 source, for reference)
Check grease in the live-tooling turret gearboxNCWhat to checkGearbox of the turret with live tooling (rotating tools)GuidelineEvery 6 months or 1000 hours. Add grease if none sticks to the part; consult the manufacturer if metal chips or coolant are mixed in (Hurco)Lubrication of the live-tool gears^[2](1 source, for reference)
Clean the hydraulic unit cooler (radiator) and wash the strainerNCWhat to checkFan-cooler fins, suction strainerGuidelineRemove dirt from the fins and straighten bent ones. Wash the strainer in a light oil such as kerosene; do not use compressed air or thinner (Makino)A clogged cooler causes oil temperature to rise; a clogged strainer causes pressure loss. If oil temperature creeps up over several months, suspect a dirty cooler (Yuken)^[4][28][17]
Clean the central lubrication unit tank and check that oil reaches the ends of the pipingNCWhat to checkLube tank, suction filter, piping downstream of the distributorGuidelineDrain and clean the tank, then fill with fresh oil. When topping up or changing, check that oil flows through each line beyond the distributorOil may flow near the unit yet not reach the far ends (Takisawa)^[4][16][29]
Check wipers on the sliding surfaces for wearCommonWhat to checkWiper lipsGuidelineReplace immediately if abnormally worn or damagedWipers protect the sliding surfaces from chips and keep the oil film even. Running with damaged wipers lets chips in and can cause serious failure (Takisawa)^[16][4]
Check hydraulic oil condition and replace it if degradedNCWhat to checkHydraulic oil in the hydraulic tankGuidelineYuken checks oil condition every 3 months for the first 6 months, then every 6 months. Replacement guideline: kinematic viscosity change ±10%, total acid number change 0.5–1.0 mgKOH/g, water content 0.2 vol% or moreMost hydraulic system failures are caused by poor hydraulic oil management (Yuken)^[17](1 source, for reference)
Change the oil in the headstock, feed box, and apronGeneral-purposeEvery 6 months to 1 yearWhat to checkOil reservoirs of the headstock, feed box, and apronGuidelineHaas's manual lathe lubrication table says every 6 months; the maintenance table on the same page says once a yearPrevents oil degradation and buildup of wear particles. The same source gives different intervals, so a range is shown to reflect how hard the machine is used. South Bend 14- and 16-inch lathes: once a year (every 6 months for heavy use). Headstock: 7.5 L of ISO VG32-equivalent oil; gearbox and apron: 1 L each of VG68-equivalent oil^[1][7]

Annual

Replace hydraulic oil and filtersNCWhat to checkHydraulic tank, suction filterGuidelineHurco: once a year or every 2000 hours (150 µm suction filter). Haas: oil every 2 years or as needed; filter once a yearDegraded or dirty hydraulic oil causes valve malfunction and unstable pressure. Okuma (US): every 6 months or 1000 hours; Takisawa: 2000 hours. Yuken does not set a fixed time; it says to test the oil and replace it if degraded^{[2][24][4][16][17]}
Clean the automatic lubrication tank and suction filterNCWhat to checkAutomatic lubrication unitGuidelineOnce a year or every 2000 hoursPrevents sediment in the tank from clogging the oil outlets^{[2][4][16][29]}
Replace the metering units in the carriage lube linesGeneral-purposeWhat to checkCarriage lube lines (metering units)GuidelineReplacement once a year is recommended. Also replace when clogged (Hardinge)A clogged metering unit stops oil from reaching that part of the ways^[3](1 source, for reference)
Measure spindle play and runoutNCWhat to checkSpindle nose (dial indicator)GuidelineHaas example: push the spindle nose by hand front to back for less than 0.0005 in (about 0.013 mm) of play; axial and radial runout at the spindle nose less than 0.0005 in. Okuma (US) lists this as an item for the distributor to doRunout is a major cause of spindle vibration (Haas)^[4][30]
Measure and adjust X and Z backlash, and adjust the gibsNCWhat to checkBacklash measurement program, gibsGuidelineOkuma (US) lists this as an item for the distributor to doPrevents dimensional drift^[4](1 source, for reference)

Other (as needed, first time, etc.)

Do the first oil change early after putting the machine into serviceGeneral-purposeFirst changeWhat to checkHeadstock, feed boxGuidelineHaas manual lathe: drain, flush, and refill the headstock after 200 hours; Colchester: 30 days after start of operationTo flush out the wear particles produced during break-in early. Idemitsu cautions to do the first change early because its multi-purpose oil has a cleaning effect^[1][8][26]
Measure coolant concentrationCommonPeriodicWhat to checkCoolant tankGuidelineMeasure regularly with a refractometer or by titration. Skim off floating debrisOut-of-range concentration reduces rust protection and lubrication. Hurco requires a coolant that does not absorb slideway oil but lets it float. Haas says to measure weekly with a refractometer and record it on a log sheet. Makino says low concentration causes poor cutting performance, spoilage, and rust, while too high a concentration causes foaming and skin irritation^[2][24][9]
Check V-belt tensionGeneral-purposePeriodicWhat to checkBelts between the main motor and the headstock pulleyGuidelineMeasure all belts with a tension gauge. In maintenance work at the University of Miyazaki, only one belt looked damaged, but the spread in the measured values showed that all three needed replacingUneven belt tension leads to slip and vibration. South Bend: check monthly and replace all belts if even one shows glazing, fraying, or cracks. Hardinge also checks tension monthly. Takisawa checks wear, cracks, and tension every 2000 hours and re-tensions new belts after 30–50 hours of running^{[31][7][3][16][32]}
Skim floating oil from the coolantCommonAs neededWhat to checkCoolant tank liquid surfaceGuidelineRemove floating oil regularly. Makino gives a pH of 8.5 or higher and below 10.5 (JIS K 2241)Floating oil covering the surface lets anaerobic bacteria grow and rot the coolant, causing odor, reduced performance, and clogged piping and filters^[9](1 source, for reference)
Care before and after a long shutdownNCWhen neededWhat to checkAutomatic lubrication system, spindleGuidelineIf the machine will be idle for 30 days or more, add a rust inhibitor to the automatic lubrication system. If the spindle has not been run for 30 days or more, run a spindle break-in before machiningPrevents rust and damage from poor spindle bearing lubrication. Hurco says skipping warm-up and break-in leads to early spindle failure, vibration, and poor surface finish^[2](1 source, for reference)
Check the spindle brake lining and switchGeneral-purposeWhen neededWhat to checkBrake band lining, brake switchGuidelineSouth Bend: replace the lining if its thinnest point is 3 mm or less. Adjust if pedal free play increasesEnsures the spindle can be stopped quickly in an emergency^[7][33]

📚Sources

Items without a mark are those confirmed by two or more sources from different publishers. Intervals, oil types and values: the specification for each machine takes priority. The text is summarized in Kezuriba's own words.