Read the material name on the exact model; cobalt labels do not describe one standard blade or service interval.
Cobalt alloy is a useful clue on a hair-scissor product sheet, but it is not one universal grade. Makers use different material names, and a brand can sell both cobalt-labelled and other shears. The exact model matters more than the heading on a steel guide.
| Model | Maker-published material and detail | What to compare |
|---|---|---|
| Joewell Cobalt 5500 | Cobalt Base Alloy CBA-1; 5.5-inch size, 53 mm blade, 37.0 g listed weight | Compare with Joewell 55, which has the same listed length and blade measurement but Supreme Stainless Alloy. |
| Mizutani New Fit PUFFIN | Extramarise II Cobalt Alloy; 5.5, 6.0, 6.5 and 7.0-inch listings, including left-handed versions | Match the listed length and handedness to the exact model a seller can supply. |
| Sam Villa Artist 6.25-inch shear | Molybdenum Alloy Steel & Cobalt on the 6.25-inch cutter; the Artist Slide Cutting shear is separately listed as 440C | Do not transfer the 6.25-inch cutter’s material to the other Artist model or the whole brand. |
These are manufacturer specifications, not our measured hardness or cutting tests. Even Joewell’s two 5.5-inch examples have slightly different listed weights. A cobalt material name does not by itself predict edge life, sharpening frequency, slide-cut feel or value for your workload.
Get the full model code and the maker’s current material sheet. Compare blade length, handle and handedness before using steel as a tie-breaker. Ask the seller who can sharpen that edge in your market, what the service costs, and whether changing the edge geometry affects the warranty. Keep the answer with the invoice.
Do not plan servicing around one hardness range or a three-to-four-month interval for every cobalt shear. The maker pages above do not support those universal numbers. A specific model’s published hardness, if supplied, belongs to that model; an edge should be assessed when its cutting changes rather than on a schedule borrowed from another shear. For broader model context, see the Joewell, Mizutani and Sam Villa profiles.