Sheffield's razor pedigree: a hidden-gem martensitic stainless with AEB-L's soul and English provenance.
Silver Fox SF100
For the Newcomer
SF100 is Sheffield's answer to Sandvik's 13C26 and Uddeholm's AEB-L: a A steel hardened by a heat-treatment that transforms its internal structure into hard, needle-like crystals called martensite. stainless steel with a A steel whose internal hard particles are small and evenly spread, which lets the edge take a cleaner, sharper apex. that started life shaving your face and ended up in some of England's most characterful handmade knives. The "SF" stands for Silver Fox, an internal steel family name from the Outokumpu mill in Stocksbridge, Sheffield. This is not a common steel; you will not find it in a department store. But if you buy a handmade knife from a Sheffield "Little Mester" (a one-person workshop-based cutler continuing a 400-year tradition), there is a real chance your blade came from this stock.
At its best (62 Rockwell C, the standard hardness scale for blade steel. Most kitchen knives fall between about 56 and 66; lower means softer and more forgiving., well heat-treated), SF100 punches close to AEB-L: excellent toughness for the hardness, a very fine Microscopic hard particles within steel that resist wear and help anchor the edge. Their size and distribution limit how hard a steel can get without becoming brittle. structure that takes a polished sharp edge, good corrosion resistance, and easy resharpening. It carries something none of the Swedish or Austrian alternatives can claim: it was made in Sheffield, the city where stainless steel cutlery was born.
About this composition
Steel history. In the early 1990s, SF77 was created by Avesta-Polarit, Precision Strip division, Stocksbridge, for razor blades destined for Gillette and Wilkinson Sword. SF100 is the successor: higher carbon (0.68%), "bigger, bolder, better edge retention." In August 2013 Outokumpu commissioned a special bloom of SF100 to mark 100 years since Harry Brearley's discovery of stainless steel at Portland Works, Sheffield, used by Stuart Mitchell Knives for a limited Centenary series of 100 numbered pieces.
Composition alone does not tell the whole story. Uddeholm and Sandvik have decades of process optimization for AEB-L and 13C26. SF100's manufacturing quality relative to those benchmarks is not independently documented in published testing. Performance is presumed similar by composition; whether the mill's carbide-size distribution and hot rolling parameters match the Scandinavian originals is unknown without independent metallurgical analysis.
Performance Deep Dive
Edge retention: Good for the steel class.
Toughness: Good.
The fine carbide structure distributes stress without fracture points. No published Charpy data found; presumed close to AEB-L.
Corrosion resistance: Good.
13% Cr is adequate for kitchen environments when the blade is dried after use. John Nowill & Sons specifically chose SF100 for their Mariner Knife (saltwater use).
Ease of sharpening: Excellent.
Low carbide volume, fine microstructure, and moderate hardness combine to make SF100 one of the most forgiving steels to sharpen. Full technique is in the care section.
Polishability: Excellent, explicitly noted by Barmond and GFS as a key feature.
The fine grain produces a highly reflective finish with standard hand-polishing.
Research Notes
No independent performance validation. Unlike AEB-L or 13C26, SF100 has no published metallurgical test results in the public knife community literature: no Larrin Thomas CATRA test, no lab-confirmed carbide study. Performance claims rest on compositional similarity to known steels and informal maker and user testing.
Availability risk. SF100 is a razor blade industry steel that happens to be available for knife use. If Outokumpu discontinued it, knife supply would disappear. Through 2025 and 2026, supply has been intermittently constrained.
Origin correction. Some early reference lists recorded SF100 with "Germany" as its origin. The correct origin is the UK (Sheffield, England), as reflected in this entry.
In the Kitchen
SF100 is the steel for cooks who want the AEB-L performance envelope with English provenance and one-of-one handmade craft. Stuart Mitchell's hand-finished cooking and eating knives sit at the top of the price range; Michael May's Japanese-profile production (nakiri, santoku) under £200 is the most accessible artisan SF100 point. John Nowill's Mariner is a genuinely interesting outlier, chosen specifically for the steel's corrosion behavior in a marine context.
Composition
| Element | % | Role |
|---|---|---|
| Carbon (C) | 0.68 | Primary hardness carrier; enables 60–62 HRC (range 0.63–0.70) |
| Chromium (Cr) | 13 | Passivation layer; corrosion resistance (range 12.5–13.7) |
| Manganese (Mn) | 0.75 | Hardenability; grain refinement (range 0.5–0.8) |
| Silicon (Si) | 0.4 | Deoxidation; minor strength improvement (range 0.2–0.5) |
Steel family: Martensitic stainless (cutlery/razor grade), ingot-cast. Successor to SF77, manufactured by Outokumpu, Stocksbridge Works, Sheffield, UK. Its primary commercial purpose is razor blade strip for Gillette and Wilkinson Sword. Knife use is a secondary application of the same razor-grade fine-carbide stainless.
Artisan Makers
| Maker | Knife | Style | Price | Link |
|---|---|---|---|---|
| Stuart Mitchell Knives | Cooking & Eating Knives (paring, table, chef styles) | Sheffield artisan (Portland Works), 2–2.2mm stock, custom kitchen/table knives | £200–£425 | stuartmitchellknives.com |
| Samuel Staniforth Ltd | Heritage Range, 9" Cook's Knife | Sheffield, est. 1864; full-tang kitchen, curly birch handle, 61 HRC | £245 (single); £497 (4-piece set, marked down from £765) | s-staniforth.co.uk |
| Michael May Knives | Nakiri | Sheffield artisan (Portland Works), Japanese-profile vegetable knife | £185 | michaelmayknives.com |
| Michael May Knives | Santoku 5" | Sheffield artisan, Japanese-profile chef | £152 | michaelmayknives.com |
| Michael May Knives | Cabbage Knife | Sheffield artisan, traditional cabbage knife | £136 | michaelmayknives.com |
| John Nowill & Sons | Master Mariner knife | Sheffield, maritime utility; SF100 chosen specifically for saltwater environments | varies | heinnie.com |