Excavator Mobile Hydraulic Shear Blade FAQ
Q: How to select matching shear blades for excavators
A: Confirm specification according to excavator weight, hydraulic pressure and oil flow. 10 to 15 ton machine uses 6 to 8 ton shear unit, working pressure 21-25MPa, oil flow 60-90L/min. 20 to 25 ton machine matches 12 to 15 ton shear unit, pressure 25-30MPa, flow 90-120L/min. Machines above 30 ton fit 18 to 25 ton shear unit, pressure 30-35MPa, flow 120-180L/min. Do not install oversized shear on small excavator, it will damage hydraulic parts.
Q: What common materials are used for shear blades and how to pick
A: H13 and H13K are regular practical materials. H13 hardness stands at HRC52-55, solid against impact and high temperature, suitable for cutting waste steel, steel bar and thin steel sheet. H13K has better toughness, fits heavy cutting of thick steel plate and high strength steel. 6CrW2Si material only works for light thin material cutting, with short working span.
Q: Cutting power is weak and cannot cut through materials
A: Low hydraulic pressure will cause insufficient cutting force, check relief valve, sealing parts and filter element regularly. Worn or broken blade edge affects cutting effect, turn blades over for reuse or change new blades. Adjust blade gap properly, keep 0.5-0.8mm for thin materials and 1.0-1.5mm for thick materials. Do not cut materials beyond limited thickness and hardness.
Q: Blade edge keeps cracking and breaking
A: Material grade does not match working load, replace with H13K blade for heavy duty work. Narrow blade gap will hurt cutting edge, adjust to standard size. Never cut hardened steel and hard alloy blocks. Fasten loose mounting bolts crosswise, fix deformed blade base timely.
Q: Cutting speed is slow and return stroke gets stuck
A: Dirty or insufficient hydraulic oil needs oil and filter replacement. Clean dirt inside blocked valve core. Add lubricant to worn pin shaft and shaft sleeve, replace worn accessories in time.
Q: Cutting surface is uneven with heavy burrs
A: Grind blunt and deformed blade edge or install new blades. Adjust gaskets to keep even gap on both sides. Calibrate tilted blade holder and tighten all fixing bolts firmly.
Q: Basic steps to install and change shear blades
A: Power off the machine and release internal pressure, loosen fixing bolts crosswise and take out old blades. Clean dirt on joint surface, align blade edge and tighten bolts evenly. Use feeler gauge to set proper blade gap. Run idle test and trial cutting before formal operation.
Q: Daily maintenance methods to extend blade service time
A: Check blade condition and bolt tightness, lubricate rotating shafts before starting work. Avoid overload cutting and add lubricant at intervals during operation. Clean iron scraps and oil stains after work, check blades for wear and cracks. Inspect blade gap and bolt tension routinely, polish cutting edge and replace hydraulic parts on time.
Q: Service life and replacement standard of shear blades
A: H13 blade can work 200 to 300 hours under normal condition, 100 to 150 hours when cutting thick steel. H13K blade lasts 30% to 50% longer. Change blades when abrasion exceeds 2mm, cracks and chips occur, or cutting quality cannot recover after blade flipping.
Q: What materials are forbidden to cut
A: Hardened steel, alloy piece, rail steel and cast iron will damage blade edge easily. Flammable explosive goods and sealed pressure containers bring safety danger. Extra large workpieces exceeding shear opening range will cause machine stuck.
