What shelf pin spacing do commercial bookcases use?

Commercial bookcases use 1/4" or 5mm pin-hole spacing in 1" or 2" increments along the interior side panels. The 1" increment provides the finest adjustment. Shelf pins are typically 1/4" diameter steel pegs — specify the correct diameter when ordering replacement pins. At OfficeFurniture2go.com, all bookcases include extra shelf pins and the specs for ordering replacements — call 1-800-460-0858 if you need compatibility guidance.