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Abrasives and belt grinding in a working knife shop

Abrasives

Grinding & Sharpening ApexUltra

ApexUltra at 64-67 HRC grinds like a stubborn 52100: feather passes and constant dunks to protect the temper, then a diamond-assisted routine at the bench.

1 min readWritten by Rich LinvilleFree to read

ApexUltra sits deliberately between worlds, and the shop experience matches: harder work than the classic carbon steels it forges like, far friendlier than the powder stainless class it cuts like. The tungsten that buys its wear resistance collects a modest tax at every abrasive step — pay it with sharp consumables and cool habits.

Cold rough-forged knife blank with hammer-scaled surface and flat tang beside a steel bar on a worn leather pad.

On the 2×72

Fresh ceramic belts make annealed ApexUltra feel like slightly stubborn 52100; worn belts make it feel like punishment — the carbides decide which shop you run. Hog annealed as always. Post-heat-treat is the real discipline: at 64-67 HRC, edges are thin, hard and expensive — sharp 120-220 ceramics, feather pressure, dunk cadence like a metronome. A blued ApexUltra edge hurts three ways: the temper, the re-treat, and the bar price. Finishing: it hand-sands well for a carbide steel and takes a handsome satin; hamon is not its game (that is W2 and 26C3 territory) but a clean etch shows a quiet quench line on differentially treated blades.

Maroon ceramic abrasive strip beside a bright ground chef knife blank with fine linear scratches on a dark bench pad

At the Bench

Good stones work; diamonds work better. The tungsten/vanadium carbide load is low enough that quality waterstones cut it honestly — slower than 26C3, faster than any PM stainless — and a diamond progression simply makes the 65-HRC edge routine. Finish on a strop with fine compound: at this hardness the apex stabilizes beautifully and push-cut keenness holds. Angles: the whole point of the steel is running 10-14 dps kitchen edges at hardness that keeps them stable — grind the thin geometry it was engineered for, per the kitchen angle guide.

Hands holding a kitchen knife at a low angle on a diamond sharpening plate in a black nonslip holder

The Quote

Budget roughly 1.5x classic-carbon shop time and premium belt consumption — then remember the finished blade’s spec sheet writes the listing. ApexUltra work is flagship work; the shop tax is part of the story the customer is buying.

Three fresh ceramic belt loops and a stack of plain finishing paper beside a satin knife blank on a leather pad

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Put the reference to work

I machine the parts, hand-assemble, track and test Torus grinders in Sterling, Illinois. Most orders ship in seven to ten business days from time of order.

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    Torus 2×72 Classic Aluminum Belt Grinder

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