Office Chair Caster Size: 60mm vs 65mm and Stems
Wheel diameter changes ride height by half the difference. The stem decides whether a caster fits at all, and 7/16 inch and 10 mm stems are not the same.
Office Chair Base: Nylon vs Aluminum, and Diameter
Nylon and aluminum bases appear at every price. BIFMA tests the base and casters together, not the material, and base diameter is rarely published.
4D Armrests Meaning: The Four Axes, Decoded
4D armrests move in four directions, but no standard says which four. Steelcase, Haworth and Sihoo each name a different set. Here is how to read it.
Seat Depth Adjustment Mechanism: What a Seat Slider Is
A seat slider is a rail under the seat pan. Three different mechanisms are sold as seat depth adjustment, and one common feature is not one at all.
Office Chair Recline Angle Explained: 90, 120, 135, 180
A recline number means nothing until you know what it is measured from. What 90, 120, 135 and 180 degrees count, and where the 135 figure came from.
Tilt Tension vs Tilt Lock: What the Knob and Lever Do
Tilt tension is a spring, tilt lock is a catch, and a tilt limiter is neither. What each control does, what the standard tests, and how to read the lines.
Types of Lumbar Support in an Office Chair, Decoded
Fixed, height-adjustable, depth-adjustable and dynamic lumbar support are four different pieces of hardware. Here is what each word means on a listing.
Office Chair Specifications Explained: Every Spec Decoded
A line by line guide to office chair specifications: which numbers are standards-backed, which are marketing words, and what a listing never tells you.