Chair Mat for an Office Chair: A Floor-First Guide
Mat, softer casters, or both? Start with your floor’s own care document. Mohawk requires a chair pad, Karndean says avoid rubber wheels.
ANSI/BIFMA X5.1
EN 1335 Type A, B and C: Not the European BIFMA
EN 1335 is three documents, and the Type A, B and C letters describe how much the chair adjusts, not how well it is built. What the rating does and does not say.
BIFMA Certified: What X5.1 Tests and What It Never Rates
BIFMA publishes a standard, it does not certify chairs. What ANSI/BIFMA X5.1 actually does to a chair, and the four things the badge cannot tell you.
Office Chair Tilt Mechanism Types: Synchro, Knee, Center
Synchro-tilt, knee-tilt, center-tilt and multi-function are four different housings under the seat. What each one pivots around, and what the ratio means.
Office Chair Gas Lift: Class 3 vs Class 4, Honestly
Class 4 is a badge on a listing. What DIN 4550 classifies, why the sources quoting it disagree, and the two numbers that decide whether a cylinder fits.
Types of Office Chair Mesh: Elastomeric, Nylon, Layered
Mesh is at least three different materials. What elastomeric, knitted nylon and layered mesh actually are, and how each one fails over years.
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.