Troubleshooting / Forging press

Forging Press Troubleshooting

The most common forging press problems on the plant floor, with the likely causes and the fix for each. Part of the OEE Lab troubleshooting directory.

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Problems on this page:

Underfill in the forgingDie cracking or wearing quicklyLaps and foldsScale pits on the surfaceDie shift or mismatchForgings sticking in the dieBillet heater faultsClutch, brake or hydraulic faultsFlash too heavy or unevenTrim press problems

Underfill in the forging

Hits OEE: Quality

Symptoms: Corners or ribs of the forging are not filled out.

Billet temperature too low
Check the heater output and the billet temperature at the press with a pyrometer.
Billet volume or weight too small
Check the billet weight against the specification.
Die lubrication wrong
Check the lubricant amount and spray pattern.
Press energy or stroke not reached
Check the press settings and condition.

Prevention: Billet temperature and weight checked on samples.

Die cracking or wearing quickly

Hits OEE: Availability

Symptoms: Dies crack or wear long before the expected life.

Dies not preheated
Preheat dies to the temperature the die maker states before production.
Dies overheating during the run
Check the die cooling and the cycle.
Lubrication not reaching the die
Check the spray system.
Die misalignment
Check the die setting.

Prevention: Die life recorded per die.

Laps and folds

Hits OEE: Quality

Symptoms: Material folds over itself and leaves a defect line.

Billet placed off centre
Check the billet placement.
Preform shape not right
Check the preform step.
Too much lubricant
Reduce the lubricant.
Die design issue
Review the die with the tool room.

Prevention: Inspection for laps on the first forgings.

Scale pits on the surface

Hits OEE: Quality

Symptoms: The forged surface shows pits from pressed-in scale.

Heating time too long
Shorten the time at temperature.
Descaling not working
Check the descaler.
Scale left on the die
Blow the die clean between parts.
Furnace atmosphere
Check the furnace or induction settings.

Prevention: Surface checked on samples.

Die shift or mismatch

Hits OEE: Quality

Symptoms: Upper and lower halves of the forging do not line up.

Die not locked
Check the die clamping.
Guides worn
Check the press guides.
Die set misaligned
Realign the dies.
Off-centre loading
Centre the billet on the die so the load is even and the halves do not shift.

Prevention: Mismatch measured on the first forging after a die change.

Forgings sticking in the die

Hits OEE: Availability

Symptoms: Parts stay in the die and must be removed by hand.

Lubricant missing
Check the spray.
Ejector fault
Check the ejector.
Die surface damaged
Repair the die.
Draft angle too small
Review the die design.

Prevention: Ejector function checked at start-up.

Billet heater faults

Hits OEE: Quality

Symptoms: Billets arrive at the wrong temperature or temperature varies.

Induction coil damaged
Inspect the coil.
Power setting wrong
Check the setting.
Billets jammed in the heater
Clear and check the feed.
Pyrometer not calibrated
Calibrate the pyrometer.

Prevention: Billet temperature logged continuously.

Clutch, brake or hydraulic faults

Hits OEE: Availability

Symptoms: The press stops, overruns, or will not develop force.

Clutch or brake wear
Check the stopping time and wear.
Hydraulic pressure low
Check the pump and relief valve.
Air supply low on air clutches
Check the air pressure.
Lubrication fault
Check the press lubrication.

Prevention: Stopping time tests on the schedule your safety plan sets.

Flash too heavy or uneven

Hits OEE: Quality

Symptoms: Flash around the parting line is thicker than normal or heavier on one side, and trimming struggles.

Billet weight above the specification
Check billet weights on samples and adjust the cutting length so excess material does not end up as flash.
Die not closing fully
Check the press setting and the shut height so the dies meet at the flash land.
Flash land worn
Measure the flash land and repair or replace the die when it is worn.
Billet placed off centre
Check the billet placement so material spreads evenly to all sides.

Prevention: Flash thickness checked on the first forgings after a die change.

Trim press problems

Hits OEE: Quality

Symptoms: Trimmed forgings show torn edges, leftover flash, or distortion from the trimming.

Trim die worn or chipped
Sharpen or repair the trim die and record the number of parts since the last repair.
Trim die not aligned with the forging
Align the trim tooling to the forging outline.
Forging trimmed at the wrong temperature
Trim at the temperature the process sets, not after the part has cooled further.
Punch pushing on a weak section
Review the punch contact with the tool room.

Prevention: Trimmed parts checked at the start of each run.

Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.

Related equipment guides: hydraulic press · stamping press · induction furnace · heat-treat furnace · shot blast machine

Stop the same fault coming back

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Related tools: full troubleshooting directory · OEE calculator · downtime cost · MTBF / MTTR · glossary

Methods that cut recurring stops: the six big losses · root cause analysis · preventive vs predictive maintenance · TPM · SMED & changeover