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Black pneumatic gas lift cylinder with chrome piston rod, 5 inch stroke, Class 4 rating

BFKK

BFKK 5" Stroke Gas Lift Cylinder 450 lbs Class 4 Black

SKU CH-04B7-KMAEK

Replaces the pneumatic piston on 99% of standard office chairs with a 50 mm centre hole, supports 450 lbs, and delivers 360° swivel plus 5 inch stroke from 11.6 to 16.2 inches

  • TypeChair & Furniture Accessories
  • Fits 99% of standard chairs with 50 mm centre hole
  • Supports 450 lbs with Class 4 BIFMA-plus piston
  • 5 inch stroke gives 16.2 in extended and 11.6 in compressed height
  • 360-degree swivel for smooth, quiet rotation
  • Installs in minutes without extra screws

Universal Fit for Standard Bases

This gas lift cylinder fits office chair bases with a standard 50 mm centre hole. It is designed to replace the hydraulic piston on 99 percent of standard office, task, executive, salon chairs and rolling stools. The part restores height adjustment without purchasing a new chair. Verify your base dimensions before ordering.

Heavy-Duty Capacity for Demanding Users

The Class 4 piston supports up to 450 lbs and meets BIFMA Plus Quality standards for durability. It suits heavier individuals who need a long-lasting replacement. Users with lighter chairs that accept lower-class cylinders or non-standard mounting patterns should look elsewhere.

5 Inch Stroke Defines Travel Range

The cylinder provides a 5 inch stroke with a fully expanded height of 16.2 inch and a fully compressed height of 11.6 inch. This exact travel distance determines whether the seat height range matches your desk and body dimensions. Confirm these measurements against your current cylinder before purchase.

Highlights

  • Fits 99% of standard chairs with 50 mm centre hole
  • Supports 450 lbs with Class 4 BIFMA-plus piston
  • 5 inch stroke gives 16.2 in extended and 11.6 in compressed height
  • 360-degree swivel for smooth, quiet rotation
  • Installs in minutes without extra screws

Specifications

TypeChair & Furniture Accessories

Questions about this item

Does my chair base need a 50 mm centre hole for this cylinder to fit?

Yes, the cylinder is designed for bases with a 50 mm standard centre hole and is compatible with 99 % of standard office, task, executive, salon chairs and rolling stools.

Will the 450 lb Class 4 rating support heavier users on an older chair frame?

The Class 4 piston is rated to 450 lbs and built to BIFMA Plus quality, making it suitable for heavy-duty use on most existing chair frames that accept a standard cylinder.

How can I confirm the 5 inch stroke is working after installation?

Measure the cylinder — it should compress to 11.6 inch and extend to 16.2 inch, giving 5 inch of smooth, quiet 360 degree swivel travel.

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