SK260LC-8 Kobelco Excavator Track Carrier Roller Assembly Forged 50Mn Steel

The YT track carrier roller assembly presented here is built for the Kobelco SK260LC-8 hydraulic excavator and doubles as a catalog cross fitment for the Kobelco SK350LC-8. Positioned along the top of the track frame, the part, which many operators simply call the top roller, supports the upper run of the track chain so it does not droop between the idler and the sprocket. With the chain held at the correct line, the excavator travels more smoothly and the whole undercarriage avoids the repeated pounding caused by a loose, slapping chain.

Carrier Roller Structure

Main Types of Carrier Rollers

• Heavy forged body: The roller is hot forged from 50Mn steel into a solid one-piece shell, providing the structural strength needed on 26-35 t class machines working in demanding ground.
• Deep hardened race: The contact surface is induction hardened to 50-55 HRC with a case depth of 3-5 mm, giving dependable mileage against hard abrasive chain contact.
• Machined shaft bore: The bore is CNC turned and honed so the roller tracks concentrically on the shaft, avoiding uneven flange loading and early seal distress.
• Robust face sealing: Duo-cone metal seals guard the internal cavity, which matters in mining and quarry conditions where dust is ever present.
• Dimensionally controlled flange: Height and thickness of the flange are checked around the circumference to guide the chain links cleanly without rubbing.
• Weather-resistant finish: Anti-rust oil plus a primer layer keeps the machined surfaces perfect from the factory floor to the job site. Main Dimensions of Installation

  Main Parameters

  Type	Model	Main Dimensions of Installation
  		A	B	D	S	M	N	G
  Dozer	D5	200	170	175	47.8
  	D6D/D6E	215	187.5	188	47.7
  	D6H	215	185	190	57.15
  	D7G	222	190	204	57.3
  	D20	142	120	110	40	100	50	12.5
  	D31	170	142	124	44
  	D40	190	165	176	55
  	D50	190	165	176	55
  	D60	215	185	200	61
  	D80	210	180	212	58

  
  

  The models above are just for reference, we can't list all models here. We can supply more products as your requirements. Please feel free to send us your inquiry.

The reference specification below applies to the YT carrier roller for the Kobelco SK260LC-8 and the Kobelco SK350LC-8. Measurements are typical catalog values intended for first-stage matching.

*Values are reference; OEM part number confirmation advised before ordering.

1. Raw 50Mn steel is verified by spectrometer against the mill certificate at goods-inward stage.
2. Billets are cut, weighed and heated in an induction furnace to a controlled forging temperature.
3. Closed-die forging produces the roller shell with flange and race allowance in a single forming step.
4. Heat treatment, including normalizing and quench-tempering, develops a strong and ductile core.
5. CNC machining centers turn the race, bore and flange to the drawing limits.
6. The race is medium-frequency induction hardened and drawn back to the target 50-55 HRC band.
7. Grinding restores precision on the bore, race and sealing faces after hardening distortion.
8. Assembly inserts the duo-cone seals and meters the correct grease volume into the cavity.
9. Final inspection combines hardness testing, magnetic particle crack checks and layout measurement.
10. Rust inhibitor is sprayed on and the roller is wrapped for export packing.
    Precison Inspection Services
    

Behind the YT brand stands XIAMEN YINTAI MACHINERY CO., LTD., founded in 2011 as a manufacturer and exporter of undercarriage systems. With 50-100 employees and annual sales between USD 10 million and USD 20 million, the company ships 90-100 percent of its output abroad. The workshop is equipped with forging presses, CNC lathes and machining centers, plus full heat treatment and induction hardening capability, which lets the team control hardness results rather than buying treated parts from outside.

The factory operates an ISO 9001:2015 quality management system and keeps traceable records from steel lot to finished serial number. Customers may request SGS or other third-party inspection at any stage, and the engineering team supports OEM/ODM requirements such as custom part numbering, special packaging and tailored delivery schedules for distribution partners.

• Mining and quarry fleets: SK260 and SK350 class machines loading rock day and night need rollers that survive silica dust and impact; the sealed, hardened YT build is specified for this duty.
• Lowering total maintenance cost: Replacing a single worn top roller early, before it damages the chain links, is far cheaper than re-tensioning a damaged chain assembly.
• Complete undercarriage renewal: For a major overhaul, YT can supply carrier rollers together with track rollers, sprockets, idlers and chain groups so all wear surfaces match from day one.
• Regional warehouse support: Importers and dealers can arrange mixed containers of YT undercarriage parts with scheduled reorders, protecting their workshops from urgent part shortages.

Compatible Brands Applications

Kobelco SK260LC-8 and SK350LC-8 excavators fitted with this carrier roller handle typical heavy applications: quarry benching, road rock excavation, dam and slope works, large-diameter pipe laying and mass earthmoving on infrastructure projects. The top roller is also a common replacement item on machines that work in wet, sticky clay conditions, where chain drag increases and the upper run carries extra load. Operators running mixed-brand fleets can standardize on the YT roller across Kobelco and other same-class machines after confirming dimensions.

Q1: Will this roller fit both the SK260LC-8 and the SK350LC-8?

The listing covers the SK260LC-8 as the main fitment with the SK350LC-8 as a catalog cross fitment. Please verify the roller diameter, width and shaft bore, or send the machine serial number for a YT check.

Q2: Is the material really forged rather than cast?

Yes, the shell is closed-die forged from 50Mn steel. Forging aligns the grain structure with the loaded sections, which gives better impact toughness than cast rollers in rock applications.

Q3: What is the expected service life?

Life depends on ground conditions and maintenance, but the 50-55 HRC hardened race and metal face seals are the two factors that most extend roller life in abrasive soils.

Q4: Do you accept small trial orders?

Certainly. The MOQ is one piece, and a sample order can be combined with fast air or express shipping when you need the roller urgently for a breakdown.

Q5: Which payment and delivery terms apply to export orders?

YT accepts T/T and L/C payments. Stocked rollers ship in 5-7 days, while production orders take 20-30 days, and each shipment includes full inspection documentation.

Finished rollers are dipped in rust-preventive oil, wrapped in moisture-proof film and loaded on steel pallets, or into individual cartons and wooden crates for mixed orders. Quality assurance documentation includes the material test certificate, hardness readings and dimensional records, and SGS pre-shipment inspection can be arranged at the buyer request. This packing system has been proven through years of container shipments to mining and construction customers around the world.

Why Choose Us?

• Through quench-tempering processes to ensure excellent mechanical properties, high strength and superior wear resistance to bending and breakage.
• Advanced Germany KUKA automatic machining center, horizontal and vertical CNC machining ensure the accuracy of assembly dimensions. This is to maximize the life span of each component and minimize production cost.
• MAKZAK Precison Finishing Machinery from Japan makes sure we have steady and good welding quality.
• We have complete production line and professional designers and working team. We can also produce any requested parts according to your blue print or samples.