ElasTek Type DO Test Block Kit

ElasTek Type DO Test Block Kit (71430-DO)

Type DO measures hardness on the same general range as the Type D scale but uses a different contact geometry: a hemispherical ball indenter rather than the flat conical point used on standard Type D. That distinction matters for specimens where a pointed indenter can’t seat evenly — curved surfaces, small parts, or localized spots too narrow for a standard D-type reading to land reliably.

Labs that test molded parts with contoured surfaces, or that need spot checks on hardware too small for a standard flat-faced block, typically reach for DO over D specifically because of that ball-tip geometry, not because the hardness range itself differs meaningfully between the two.

As with the rest of CCSi’s durometer reference kits, blocks are color coded, ship in a latching storage case, and are available for individual replacement if one wears out. ISO-17025 calibration is included, and CCSi recommends annual recalibration, which CCSi also performs directly.

(Note: confirm the exact nominal hardness values and block count for this kit with manufacturing before publishing — the current source page shows the same 5-block, 45/55/65/75/85 spec as the standard Type D kit, which may not reflect the DO-specific configuration.)

If your testing surface is flat and a standard indenter works fine, the Type D kit is the more common choice and likely the lower-cost option.