Product Overview

The HS53C20105G1 Capscrew is a genuine OEM fastener engineered specifically for the Kobelco SK220XD-10 excavator, where it serves as a swing circle mounting bolt securing the upper structure to the undercarriage. This is one of the most critical fasteners on the entire machine.

The swing circle (also known as the slewing ring or turntable bearing) is the large-diameter bearing that connects the excavator’s upper structure (cab, engine, boom) to the lower undercarriage (tracks, final drives). It allows the upper structure to rotate 360 degrees while supporting the full weight of the machine’s upper half and withstanding digging forces, lifting loads, and impact shocks.

The HS53C20105G1 capscrew is one of approximately 30-50 high-strength bolts that secure the swing circle inner or outer ring to the mating flange on the upper or lower frame. These bolts must withstand:

• Axial loads: The full weight of the upper structure (approximately 12-15 tons on the SK220XD-10)

• Radial loads: Digging forces, side loading, and impact shocks

• Overturning moments: Torque forces when digging or lifting at maximum radius

• Vibration: Continuous machine operation and travel over rough terrain

The Hino J05ETG engine in the SK220XD-10 develops 118 kW at 2,000 rpm and 569-592 N-m of torque , producing significant vibration that these fasteners must resist. The swing circle itself rotates at up to 13.3 rpm , and the bolts are subjected to cyclic loading with every swing motion.

A loose or failed swing circle bolt can lead to catastrophic structural failure, causing the upper structure to separate from the undercarriage — a severe safety hazard. Using the correct OEM-spec capscrew with proper torque is therefore absolutely critical.

Key Features

• Swing Circle Application: Specifically engineered as a swing circle (slewing ring) mounting bolt for the SK220XD-10.

• High-Strength Material: Manufactured from high-tensile alloy steel rated for the extreme axial and radial loads encountered during excavator swing operation.

• Precision Threads: Machined to exact JIS/metric thread specifications for proper engagement with swing ring or frame threads.

• Hexagon Head Design: Standard hex head configuration compatible with torque wrench for precise tightening to OEM specifications.

• Corrosion-Resistant Finish: Treated with appropriate plating to resist rust and corrosion in undercarriage environment.

• Proper Hardness: Heat-treated to achieve correct Rockwell hardness, preventing thread stripping or bolt stretching under cyclic loading.

• OEM Guarantee: Genuine Kobelco part with documented import history .

Compatibility

This capscrew is a direct OEM replacement for the following application:

Excavator Models

• Kobelco SK220XD-10

• Kobelco SK220XDLC-10

Part Number: HS53C20105G1

Application: Swing Circle (Slewing Ring) Mounting Bolt / Turntable Bearing Bolt

Brand: KOBELCO (OEM)

Condition: Brand New, OEM Quality

HS Code: 73181900 

Country of Origin: Japan 

Also Known As: Swing Circle Bolt, Slewing Ring Bolt, Turntable Bearing Bolt, Upper/Lower Frame Mounting Bolt

Please verify your machine’s serial number and confirm this is the correct bolt for your specific swing circle application before purchasing.

Swing Circle Bolt Function Explained

The swing circle (slewing ring) on the SK220XD-10 consists of:

• Inner Ring: Bolted to the upper structure (or lower frame, depending on design)

• Outer Ring: Bolted to the opposite frame

• Rolling Elements: Balls or rollers between the rings for smooth rotation

The HS53C20105G1 capscrew secures one of these rings to its mating flange. The bolt pattern typically includes:

Industry Verification

The HS53C20105G1 part number appears in verified import documentation as a genuine Kobelco spare part. A customs entry from March 2016 shows:

“CAPSCREW (P/N: HS53C20105G1) (SPARE PARTS FOR KOBELCO EXCAVATOR)” with country of origin Japan 

This confirms the part’s OEM status and long-term availability.

Signs Your Swing Circle Bolts Need Replacement

Swing circle bolts are subject to fatigue over thousands of operating hours. Replace the HS53C20105G1 capscrews if you observe:

1. Swing Circle Looseness: Visible play between the upper structure and undercarriage when swinging or traveling over rough terrain.

2. Unusual Swing Noise: Grinding, popping, or clicking sounds during swing operation may indicate loose or broken bolts.

3. Visible Bolt Damage: Stripped threads, corrosion, bent bolts, or cracked bolt heads.

4. Broken Bolt Removal: If any swing circle bolt has broken and been removed, all bolts in the affected ring should be replaced.

5. During Swing Circle Replacement: When replacing the entire swing circle or slewing bearing, always install new OEM bolts.

6. After Major Structural Repair: Following accident repair or frame straightening, bolts should be replaced.

7. High Operating Hours: As a preventative measure, consider bolt replacement during major overhaul (10,000+ hours).

8. Previous Overtorque: If bolts have been significantly overtorqued during previous service, they may be permanently stretched.

Consequences of Swing Circle Bolt Failure

Benefits

Why choose our HS53C20105G1 OEM Capscrew for your Kobelco SK220XD-10 swing circle?

1. Ensures Structural Integrity: Properly torqued OEM bolts maintain secure connection between upper structure and undercarriage.

2. Prevents Catastrophic Failure: Swing circle bolts are safety-critical components. Quality fasteners prevent upper/lower structure separation.

3. Maintains Swing Circle Longevity: Proper clamp load ensures even load distribution on swing circle bearings, extending ring life.

4. Essential for Swing Circle Replacement: When replacing the swing circle, new bolts are mandatory for proper assembly.

5. Corrosion-Resistant: OEM finish protects against rust in the exposed undercarriage environment.

6. Verifiable Quality: Genuine Kobelco part with documented OEM status .

7. Protects Equipment Investment: One of the most critical fasteners on the excavator — proper bolts prevent major structural damage.

8. Operator Safety: Directly affects the safety of the operator and ground personnel by preventing structural separation.

Installation Tips

• Professional Installation Required: Swing circle bolt replacement requires specialized tools, torque equipment, and structural knowledge. Professional installation is mandatory.

• Replace All Bolts in Ring: Never replace a single swing circle bolt. Replace all bolts in the affected ring simultaneously.

• Clean Threads Thoroughly: Remove all dirt, debris, and old thread locker from threaded holes before installation.

• Use Correct Torque: Follow the SK220XD-10 Service Manual (Publication No. S5YN0063E04) for specific torque values, which are critical for swing circle bolts.

• Apply Thread Locker: Use the recommended thread locking compound specified in the service manual.

• Follow Tightening Sequence: Use the specified cross-pattern or circular sequence for even clamp load distribution.

• Torque in Stages: Tighten in multiple stages (e.g., 50%, 75%, 100% of final torque) to ensure proper seating.

• Check Torque After Operation: Re-check bolt torque after initial operation and again after 50 hours of work.

• Do Not Reuse: Never reuse swing circle bolts that have been removed. Always install new ones.

Why Choose Our HS53C20105G1 Swing Circle Bolt?

We understand that the Kobelco SK220XD-10 is a sophisticated 21.8-ton excavator operating in demanding applications. The swing circle is one of the most critical structural joints on the machine, and the bolts that secure it are literally holding the machine together.

Our HS53C20105G1 Capscrew is a genuine Kobelco OEM component, manufactured to the exact specifications required for swing circle mounting. This part is documented as an authentic Kobelco spare part in import/export records . Whether you are replacing a worn swing circle, performing major structural repair, or overhauling the machine, this OEM capscrew provides the proper grade, precise fit, and reliable performance your SK220XD-10 requires.

Technical Specifications

Order your HS53C20105G1 Swing Circle Capscrew today and ensure secure structural integrity for your Kobelco SK220XD-10 excavator’s slewing ring. In stock and ready for immediate worldwide shipping. Bulk pricing available for complete swing circle bolt sets.