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⚙️ Round Internal Rubber Cap | RUBASIA RUBBERTECH INDUSTRIES

The Best | The Largest Manufacturer | The Highest Quality | Market Leader | The Biggest | The Widest Range in Borneo (Sabah, Sarawak, Brunei)

RUBASIA RUBBERTECH INDUSTRIES is the Market Leader and The Largest Manufacturer of Round Internal Rubber Caps across Sabah, Sarawak, and Brunei.

Our Round Internal Rubber Cap series is precisely engineered to be inserted into the internal bore of a circular tube, metal pipe, or furniture leg, forming a tight interference fit that provides mechanical protection, sealing, and vibration isolation.

Designed and manufactured under ISO 9001:2015 quality management, each cap delivers precision tolerance, dimensional stability, and superior mechanical resilience, making RUBASIA a trusted supplier to industrial, marine, furniture, and construction sectors throughout Borneo.

 

🧩 Technical Specification Table

Property	Specification	Description
Product Type	Round Internal Rubber Cap	Internal-fitting end protection component
Size Range (ID)	19mm, 22mm, 25mm, 32mm, 38mm, 51mm	Nominal internal tube diameter fit
Outer Flange Diameter (OD)	+1.5mm above tube ID	Ensures interference fit for sealing
Material Options	NR, EPDM, NBR	Natural Rubber, Ethylene Propylene Diene Monomer, Nitrile Rubber
Hardness	60 ± 5 Shore A	Standard durometer rating for flexibility + rigidity balance
Tensile Strength	12 – 20 MPa	Material strength against elongation and tearing
Elongation at Break	300% – 500%	Ability to deform before failure
Compression Set (22 hrs @ 70°C)	≤ 25%	Maintains resilience under constant load
Temperature Resistance	-30°C to +120°C	Suitable for indoor/outdoor environments
UV & Ozone Resistance	Excellent (EPDM)	Non-cracking and color stable
Oil & Fuel Resistance	Excellent (NBR)	Ideal for automotive and industrial environments
Water Absorption	< 1%	Maintains dimensional integrity
Surface Finish	Matte or Semi-Gloss	Non-slip aesthetic finish
Standard Color	Black	Custom color available upon request
Manufacturing Method	Compression / Injection Moulded	Ensures uniform density and dimensional precision
Compliance	RoHS, REACH, ISO 3302-1 Class M2	Certified quality and tolerance control

🔍 Engineering Function & Mechanical Role

1. Internal Fit Geometry

Each Round Internal Rubber Cap is designed with a tapered insertion body that forms a compression seal within the inner diameter of the tube.
This creates a mechanical interference of 0.5–1.0mm, ensuring:

• Positive sealing pressure against inner walls
• Zero play or movement during vibration or impact
• Stable grip without adhesives or mechanical fasteners

2. End Wall Construction

The cap’s solid base wall thickness (typically 3.0–5.0mm) provides:

• Structural rigidity under axial load
• Impact resistance for vertical compression (e.g., chair legs)
• Noise reduction by energy absorption through rubber elasticity

3. Material Behavior

The elasticity of EPDM or NR ensures that the cap deforms elastically during insertion and returns to its natural shape, creating a tight, long-term hold that withstands thermal expansion or mechanical stress.

4. Stress & Impact Performance

Under vertical compression (200–400 N), deformation remains below 15%, ensuring consistent load support and anti-slip stability.

Dynamic fatigue testing over 50,000 compression cycles shows no cracking or loss of fit integrity.

 

🧪 Material Selection and Technical Behavior

Natural Rubber (NR)

• Excellent rebound elasticity and mechanical damping
• Good tear resistance
• Ideal for indoor use on furniture and light mechanical structures

EPDM Rubber

• High weather and ozone resistance
• Excellent electrical insulation and UV stability
• Maintains elasticity across temperature cycles
• Preferred for outdoor structures, construction frames, and marine equipment

Nitrile Rubber (NBR)

• Outstanding oil, grease, and hydrocarbon resistance
• Suitable for industrial, automotive, and machinery sealing applications
• Retains mechanical strength at elevated temperatures

 

🧱 Performance Attributes

Property	Result	Test Method
Abrasion Resistance	Excellent (loss < 120 mm³)	DIN 53516
Tear Strength	>25 kN/m	ISO 34-1
Ozone Resistance (100 pphm, 40°C, 72h)	No Cracks	ASTM D1149
Ageing Resistance (70°C, 168h)	No Hardening or Cracks	ASTM D573
Compression Recovery	97%	ISO 815
Dimensional Tolerance	±0.2mm	ISO 3302-1 Class M2

🏗️ Functional Applications

1. Structural & Mechanical Engineering

• End protection for steel frames, tubes, scaffolding, and support legs
• Prevents metal fatigue, corrosion, and contamination ingress

2. Furniture & Interior Architecture

• Applied on chair and table legs, display stands, benches, and storage racks
• Provides shock absorption, noise reduction, and surface protection

3. Industrial & Automotive

• Sealing for hydraulic tubes, oil system piping, and instrument frames
• NBR variant used for fuel-resistant and oil-line end caps

4. Marine & Offshore

• Protects stainless steel railings, boat ladders, and ship interior fittings from corrosion
• EPDM version resists saltwater exposure and UV degradation

5. Laboratory & Medical

• Used in stainless steel furniture, trolleys, and instrument stands
• Ensures hygiene by sealing hollow ends from dust or microbial accumulation

 

🛠️ Installation Engineering Notes

1. Dimensional Preparation:
   Ensure the tube inner diameter (ID) matches the cap’s nominal size. Tolerance recommendation: ±0.3mm.
2. Insertion Method:
   Apply uniform pressure along the cap axis to achieve full seating.
   Avoid twisting which can shear the rubber.
3. Thermal Softening Technique (Optional):
   Immerse the cap in 60°C water for 2–3 minutes to temporarily soften rubber for easier insertion in tight-fit applications.
4. Adhesive Use:
   Normally unnecessary. For high-vibration or high-pressure environments, a thin layer of rubber-safe adhesive (e.g., neoprene contact cement) may be applied.
5. Inspection:
   Ensure no gaps exist between the cap flange and the tube edge.
   Verify full contact for sealing performance.

 

🌍 Regional Distribution – Borneo Coverage

RUBASIA RUBBERTECH INDUSTRIES supplies and supports industrial clients across:

Sabah: Kota Kinabalu, Sandakan, Tawau, Lahad Datu, Keningau, Tenom, Kudat, Ranau, Papar, Beaufort, Tuaran, Kota Belud, Tambunan, Sipitang, Semporna, Kunak, Penampang, Putatan, Bongawan, Nabawan, Tongod, Telupid.

Sarawak: Kuching, Miri, Sibu, Bintulu, Limbang, Kapit, Sarikei, Betong, Bau, Mukah, Lawas, Serian, Sri Aman, Lundu, Simunjan, Asajaya, Belaga, Kanowit, Julau, Song, Pakan, Sebuyau.

Brunei: Bandar Seri Begawan, Kuala Belait, Seria, Tutong, Bangar, Lumut, Muara, Jerudong.

Our logistics network covers industrial estates, furniture manufacturers, engineering workshops, and hardware distributors across Borneo, offering bulk orders, OEM labeling, and export packaging.

 

🏆 Why RUBASIA RUBBERTECH INDUSTRIES Leads the Market

✅ The Largest Rubber Cap Manufacturer in Borneo
✅ The Widest Range of Internal Fit Sizes (19–51mm)
✅ The Highest Precision and Quality Control Standards (ISO 3302-1 M2)
✅ The Best Mechanical Performance and Longevity
✅ The Market Leader in Rubber Moulding and OEM Customization
✅ The Biggest Production Capacity and Regional Supply Network