Max Knives SP61 — Folding diamond sharpener, coarse and fine

Overview

A dull edge is more dangerous than a keen one: it does not bite into the material, it skates across it, and that slip is what causes accidents. The SP61 exists so it never gets that far. It is a folding diamond sharpener, 230 mm open and 125 mm closed, with a sharpening area 95 mm long by 21 mm wide — the widest of the four folding models in the series. One face in 400 grit, one in 600: enough to take the working blades in hand regularly, before they have nothing left to bite with.

Start at 400, finish at 600

The two grits do different jobs and are not used in any order you please. The 400 is the grit that removes metal: it cuts into the steel, clears the small rolled spots along the edge and reforms a bevel where it had gone round. The 600 reforms nothing, it refines: it closes up the scratches left by the first and makes the edge even. So you always work from 400 to 600, never the other way — finishing on the coarse face would undo what the fine one achieved. A few passes on each side, at a steady angle, and the edge is back.

Technical specifications

Two-sided folding diamond sharpener: 600 grit on one face for finishing, 400 coarse grit on the other for reshaping. Length open 230 mm, length folded 125 mm. The sharpening area measures 95 mm long by 21 mm wide. Those 21 mm give slightly more bearing surface under the blade than the other folding models in the series, while the 105 mm saved by folding brings the tool back to pouch size.

Care

Grit loaded with filings slides instead of cutting: clean both faces after use with a soft brush or clean water, then wipe them down. Dry them properly before folding, since moisture has no business sitting between the handles. There is no need to lean on the tool while sharpening — diamond works through repeated passes rather than pressure, and that is also what keeps the grit in shape from one session to the next.