Mechanical evaluation of the Chairpartsonline Adjustable Office Chair Armrests reveals a structural upgrade for legacy office seating. The assembly consists of a high-density polyurethane (PU) soft pad mounted to a reinforced polymer vertical column. Unlike friction-based systems, the height adjustment mechanism utilizes a 5-point internal ratcheting lock, ensuring the vertical position remains constant under loads of up to 40 lbs per arm.
The mounting interface features a universal plate designed to support standard 4-bolt configurations, typically utilizing 4-inch by 4-inch spacing. The high Shore hardness of the PU padding resists localized deformation (bottoming out), though the polymer telescoping tubes may exhibit minor lateral wobble inherent to the material tolerances.
Technical documentation indicates that the PU material is subject to UV-induced degradation and surface pitting over long-term exposure. Proper installation requires verifying the under-seat chassis bolt pattern to prevent mechanical misalignment.
These adjustable armrests are recommended for restoring ergonomic functionality to executive chairs with degraded or fixed arm assemblies.
This hardware fits into the custom chair components sector of ergonomic workstation optimization.
