What preventive maintenance should I perform on shears?

Learn what preventive maintenance to perform on roll forming shears to prevent burrs, misfires and hydraulic failure.

Preventative maintenance varies slightly depending on shear type:

• Hydraulic stop-cut shear

• Flying hydraulic shear

• Servo flying shear

• Saw cutoff systems

But the core maintenance principles remain the same.

1️⃣ Daily Maintenance (High Production Lines)

Perform quick checks before or after shift:

✔ Inspect blade edges
✔ Remove metal debris
✔ Check hydraulic leaks
✔ Listen for abnormal noise
✔ Confirm smooth cylinder movement
✔ Verify home position sensor

If running heavy gauge or high tensile material, daily checks are critical.

2️⃣ Blade Inspection & Maintenance

Blades are the most wear-prone component.

Inspect:

✔ Burr formation
✔ Edge rounding
✔ Chipping
✔ Uneven wear
✔ Edge alignment

Frequency:

• Light gauge: weekly inspection

• Heavy gauge: daily inspection

Blunt blades increase hydraulic load and cause burrs.

3️⃣ Blade Gap Adjustment

Incorrect blade clearance causes:

• Burrs

• Deformation

• Increased load

• Poor cut finish

Check blade clearance:

✔ When changing material thickness
✔ If burr appears
✔ Monthly under steady production

Proper gap reduces shock load.

4️⃣ Hydraulic System Maintenance

Shears rely on stable pressure.

Weekly:

✔ Check oil level
✔ Inspect hoses
✔ Inspect fittings
✔ Monitor pressure gauge

Every 3–6 months:

✔ Replace filters
✔ Check relief valve setting

Hydraulic instability causes slow or incomplete cuts.

5️⃣ Cylinder & Guide Rail Inspection

Flying shears have moving carriages.

Inspect:

✔ Guide rails
✔ Linear bearings
✔ Lubrication condition
✔ Carriage alignment
✔ Mounting bolts

Monthly inspection recommended.

Poor lubrication causes binding and misfires.

6️⃣ Check Fasteners & Structural Integrity

Impact forces loosen bolts.

Inspect:

✔ Blade mounting bolts
✔ Frame bolts
✔ Carriage bolts
✔ Sensor brackets

Re-torque monthly or quarterly depending on production intensity.

7️⃣ Sensor & Position Calibration

Flying shears require:

✔ Home position verification
✔ Encoder calibration
✔ Length accuracy testing

Quarterly verification recommended.

Misalignment leads to length drift.

8️⃣ Check Return Speed & Damping

Shear must:

• Cut

• Return smoothly

• Synchronize for next cycle

If return too slow:

• Cycle timing affected

Inspect:

✔ Flow control valves
✔ Return springs (if used)
✔ Servo tuning

9️⃣ Debris Removal

Metal scrap builds up around:

• Blade housing

• Carriage rails

• Cylinder rod

Clean weekly under moderate production.

Debris increases wear and misalignment.

10️⃣ Monitor Shear Alignment

Misalignment causes:

• Crooked cuts

• Tool wear

• Profile distortion

Check:

✔ Blade parallelism
✔ Frame squareness
✔ Strip tracking

Quarterly alignment check recommended.

11️⃣ Lubrication Points

✔ Guide rails
✔ Linear bearings
✔ Moving joints
✔ Pivot points

Frequency depends on usage:

• Weekly under heavy use

• Bi-weekly under light use

Use correct lubricant — not excessive grease.

12️⃣ Signs Maintenance Is Overdue

• Burrs increasing

• Cut face rough

• Cylinder slowing

• Hydraulic overheating

• Shear vibration

• Misfires at high speed

These indicate inspection frequency should increase.

Professional Maintenance Schedule

Light Production (≤4 hrs/day):

• Blade inspection: bi-weekly

• Hydraulic check: monthly

Medium Production (8 hrs/day):

• Blade inspection: weekly

• Hydraulic check: weekly

• Alignment check: quarterly

Heavy Production (16 hrs/day):

• Blade inspection: daily

• Hydraulic inspection: weekly

• Guide lubrication: weekly

• Calibration: quarterly

Why Shear Maintenance Is Critical

Poor shear maintenance leads to:

• Scrap

• Tool damage

• Hydraulic overload

• Safety risks

• Extended downtime

The shear is one of the most mechanically stressed components in the line.

Final Expert Insight

Preventive maintenance on shears should focus on:

✔ Blade condition
✔ Blade clearance
✔ Hydraulic stability
✔ Guide rail lubrication
✔ Structural bolt integrity
✔ Sensor calibration

The most common real-world issue is dull blades combined with improper clearance, which increases hydraulic load and accelerates failure.

Consistent shear maintenance protects:

• Product quality

• Hydraulic system

• Motor load

• Timing accuracy

• Overall machine reliability