Max Knives MKO12S2 — Grey OTF automatic karambit, 80 mm blade

Overview

The pairing is a rare one: the shape of a karambit, which normally belongs to fixed blades or pivot folders, set on an automatic front-opening mechanism. The MKO12S2 deploys its 80 mm curved blade upwards at the press of the push button, and pulls it back through the same control since it works in double action. The 420 steel blade is ground on a single edge, the inside of the curve, and receives a grey plasma treatment; the 150 mm handle combines silver aluminium with carbon fibre, for 220 mm open and 277 g. A belt clip, a lanyard hole and a nylon sheath complete the CNC-machined piece.

The karambit: a blade that works on the pull

The karambit comes from South East Asia, where the name describes a blade curved into a claw, derived from a farming tool. Its logic is the reverse of a straight knife: instead of pushing the blade forward, you hook it and draw your hand back towards you. The curve then does all the work, because the material stays trapped inside the hook instead of escaping ahead of the edge, and the cut continues along the whole arc throughout the pulling motion. That is why it was adopted for drawing movements: opening, clearing, severing something held in the other hand. On the MKO12S2 that curve carries its edge on the inside only, the back staying solid.

57 HRC: what the number means

The Rockwell C scale measures the hardness of a hardened steel: a diamond point is pressed into the sample under a set load and the depth of the impression is read off. The harder the steel, the less the point sinks in, and the higher the number. Knives generally sit between 54 and 62 HRC, and the figure expresses a permanent trade-off. A very hard steel holds the geometry of its edge for a long time but turns brittle and awkward to rework; a softer steel is easy to work and absorbs shocks, while its edge deforms sooner. The 57 HRC quoted for the 420 steel blade of the MKO12S2 places it in the lower, versatile part of that range, on the tough side.

Technical specifications

A curved karambit blade, 80 mm, in 420 steel, single edge, with a hardness of 57 HRC, grey plasma treatment and CNC machining. A 150 mm handle in silver aluminium and carbon fibre. Overall length with the blade deployed: 220 mm. Weight: 277 g. Automatic front opening of the OTF double action type, upwards, controlled by a push button. The knife takes a belt clip and a lanyard hole, and ships with a nylon sheath.

Care

The inside of the curve is the area that holds on to everything: work a cloth wrapped around a stick along the arc from end to end rather than using a finger. The grey plasma finish asks for nothing more than warm soapy water; abrasives and polishing creams have no business near it. The exit track deserves a blast of dry air after any dusty outing, since the curved blade drags debris back in every time it retracts. Finish with a trace of fine oil in the mechanism and a thorough drying of the carbon fibre scales.

Legal notice. Age-restricted item (18+). In France this knife is a Category D item: legal to sell but reserved for adults, with age verification at checkout. Automatic and OTF knives are restricted or prohibited in many countries — the United Kingdom, Germany and several US states among them. It is the buyer's responsibility to check the law that applies where the order is delivered before purchasing.