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SPY27 is a stainless powder steel developed for Spyderco. Published experiments give it more substance than a proprietary name alone, including toughness and corrosion testing. It is worth considering as part of the complete knife, while keeping tested findings separate from predictions about edge life.
What Is CPM SPY27?
CPM SPY27 was developed for Spyderco with Crucible. Its composition includes chromium, vanadium, niobium, nitrogen and cobalt, but it is not simply S35VN or VG-10 under a different name. The chemistry shown here is Spyderco's reported formulation.
What Has Been Tested?
In his 2020 SPY27 experiments, Dr. Larrin Thomas measured hardness, toughness and corrosion resistance. Toughness was close to S35VN and corrosion behavior similar to S30V under the conditions tested. Those are useful comparisons, but they do not establish that every finished SPY27 knife will match every knife in those steels.
That study did not include an edge-retention experiment. Its wear and sharpening expectations should therefore be read as predictions in that article, rather than measured cutting-life results. We do not turn them into a numerical score.
Sharpening and Stainless Care
For sharpening, follow the existing bevel, use an abrasive that removes metal effectively and pay attention to burr removal. A repair or angle change takes different work from a routine touch-up, so avoid expecting a fixed sharpening time from the name alone.
SPY27 is stainless, but clean and dry the knife after wet use or contact with salt and food residue. Its tested corrosion behavior is useful context, not a reason to ignore the materials in the pivot, screws and other parts.
Choosing a SPY27 Knife
Choose the blade shape, handle and carry size that fit your use, then consider the available steel evidence. SPY27 has published testing behind it, but the complete knife still determines much of the experience. If long abrasive cutting life is your main reason to buy, look for relevant cutting evidence for the exact version rather than treating predicted wear resistance as a guarantee. Our knife steel guide explains the broader tradeoffs.
Composition
Our composition guide explains what alloy values can and cannot tell you.
CPM SPY27: Spyderco knife-maker-reported composition: ranges and single reported values, not a producer batch certificate. Spyderco: steel chart.
| Element | CPM SPY27 |
|---|---|
| Carbon (C) | 1.25% |
| Chromium (Cr) | 14% |
| Molybdenum (Mo) | 2% |
| Vanadium (V) | 2% |
| Niobium (Nb) | 1% |
| Nitrogen (N) | 0.1% |
| Cobalt (Co) | 1.5% |
| Manganese (Mn) | 0.5% |
| Silicon (Si) | 0.5% |
Compare Two Knife Steels
Sources and Update Notes
This steel is not included in the numerical ratings used by our comparison tool.
