Oem Factory Price Hard Rock Excavation Machine Boom Oil Cylinder Built-In Seal Groove Cylinder Good Hydraulic Cylinders – We Make Sure Inside Parts
The tube follows GUOYUE CD250 style.
Tube steel can be 45#, 42CrMo, or 27SiMn.
Hole is ground to H8 and feels smooth, Ra under 0.4 μm.
Head, base, ears, and piston are only 45# steel.
We do not use cast iron or cast steel. Slow-Down Parts
You can pick fixed bumpers or floating bumpers so the rod slows down safe at any speed or load. Welds
We hit every heavy-load weld with ultrasound.
This takes away most of the stress and makes the weld last longer. Seals
We only use top seals from NOK (Japan), Trelleborg (Sweden), Merkel and GP (Germany).
We do not use local seals. Checks
Each cylinder is tested to GB/T15622-2005 and our own Q/GAKY014-2023.
You get a test sheet and a pass paper. Promise
We give one year cover from ship date.
If it breaks because of how we made it, we fix or swap it for free.
This cylinder is strong. It uses thick steel and hard rod. It does not bend. The seal keeps oil in, no leak. It has many tubes that slide out one by one. It lifts high but stays short Advantages :
She’s the iron muscle with a velvet soul. A factory-price boom cylinder built to bite granite, yet her built-in seal groove hugs O-rings like a mother’s arms—no leaks, no tears, just smooth, quiet power. Chrome rod shrugs off boulders and dust storms; OEM fit means she slides straight onto your excavator like she’s always belonged. Day after dusty day she murmurs, “Push harder, I’ve got the rock,” and the operator feels the mountain move instead of his heart skip. Application scenes :
Picture sunrise on a mountain cut: the boom dips, teeth bite basalt, and she lifts a ton of stubborn stone without a shudder. Or a tunnel crew carving subway lines beneath the city, her steady push keeping drills on track while traffic hums above. From quarry faces to dam foundations, she’s the patient heartbeat that turns brute stone into tomorrow’s roads.

Application	Engineering machinery, mine, shipping, metallurgy, water conservancy, offshore, agriculture, etc.
Seal	Parker, Merkel, NOK, Hallite,etc.
Paint	Red, Grey, Yellow, Black, etc.
Material	St52, CK45, 4140, Duplex2205, Stainless Steel 304/316, etc.
Certificate	ABS, Lloyds, SGS, etc.
Package	Bubble-wrap packing, then in wooden case.
Color	choose the color according to customer requirement
Core components	Bearing,Pressure vessel,Pump
Is it a standard part?	Nonstandard
Structure	Piston Type, Plunger Type, Telescopic Type,
Power	Hydraulic & Pneumatic
Brand	Guoyue
Sample	Available