Abstract: An autoclavable dental bur block or portable holder for dental burs and the like having elastomeric insert receptacles adapted to releasably hold burs of different shank diameters, with the receptacles color coded and arrangeable and rearrangeable in organized manner as a convenient means to identify and organize the different kinds of burs in the holder. The tubular insert receptacles have a downwardly tapered central bore, including an upper portion of relatively large average diameter extending above the support panel to accommodate large-shank burs, and a lower portion extending below the support panel to accommodate small-shank burs. Dovetail fitting elements on the sides of the bur blocks adapt them to interengage complemental fittings on other blocks so as to hold a plurality of the bur blocks in substantially coplanar relationship permitting them to be handled as a composite unit.