Avoiding Common Pitfalls in Selecting Jack Rubber Support Blocks
Jack rubber support blocks are critical for cushioning, vibration absorption, and load distribution. Selecting the wrong type or material can compromise safety, reduce lifespan, and lead to operational failures. Understanding the key selection criteria and avoiding common mistakes ensures reliable performance.
1. Material Compatibility
One of the most common pitfalls is choosing a rubber material that is incompatible with the operating environment.
Chemical Exposure: Nitrile butadiene rubber (NBR) is suitable for oil and fuel exposure, whereas EPDM excels in outdoor, ozone, and weather-resistant applications. Avoid natural rubber in environments with solvents or petroleum products.
Temperature Resistance: High-temperature operations require heat-resistant materials like silicone or specially formulated polyurethane. Low-temperature environments need rubber with maintained flexibility, such as EPDM or low-temperature NBR.
2. Hardness and Elasticity Mismatch
Selecting an inappropriate hardness leads to either excessive deformation or brittleness.
Too Hard: Can cause cracking under impact and reduced cushioning.
Too Soft: Leads to permanent compression, bulging, and loss of load-bearing capacity.
Ensure the Shore A hardness matches the load requirements and operating conditions, typically between 60–90 depending on jack capacity.
3. Overlooking Load and Stress Distribution
Rubber blocks must be sized and shaped to distribute loads evenly. A common mistake is underestimating localized stress, which accelerates wear, deformation, and cracking. Proper dimensional design and alignment with the jack’s contact surface are essential.
4. Ignoring Environmental Aging Factors
UV, ozone, and moisture can degrade rubber over time. Not accounting for these factors can shorten service life. Select materials with adequate resistance and, if needed, apply protective coatings to reduce exposure.
5. Neglecting Installation and Fixation Requirements
Rubber blocks must be properly bonded or mechanically fixed to prevent slippage or detachment. Using incompatible adhesives or improper fastening methods can lead to early failure. Always follow manufacturer installation guidelines.
6. Preventive Measures
Assess the operating environment, including chemical, thermal, and mechanical conditions.
Match rubber hardness and elasticity to load and cushioning requirements.
Ensure proper dimensions and surface compatibility for even load distribution.
Use appropriate bonding or mechanical fixation techniques.
Consider protective coatings or storage methods to reduce environmental aging.
Inspect rubber blocks regularly and replace them before significant degradation occurs.
Conclusion
Avoiding common pitfalls in selecting jack rubber support blocks requires careful consideration of material compatibility, hardness, load distribution, environmental resistance, and proper installation. Following these guidelines ensures safety, durability, and optimal performance.
References
Gent, A. N. Engineering with Rubber: How to Design Rubber Components. Hanser Publishers, 2012.
ASTM D2000 – Standard Classification System for Rubber Products in Automotive Applications.
Lake, G. J. “Fatigue and Fracture of Elastomers.” Rubber Chemistry and Technology, 2000.
ISO 7619-1 – Rubber, Vulcanized or Thermoplastic — Determination of Indentation Hardness.
