What caster material should conference chairs have for hardwood floors?

For hardwood, luxury vinyl, tile, and other hard floor surfaces, conference chairs should use soft PU (polyurethane) or rubber casters — sometimes called 'chair mats not required' casters — with a Shore A hardness of 65–75. Hard nylon casters appropriate for carpet will scratch and scuff hard floors. OfficeFurniture2go.com can supply conference chairs with hard-floor casters — call 1-800-460-0858.