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Abrasives and belt grinding in a working knife shop

Abrasives

Grinding and Sharpening A2: Belt Recommendations & Technique

A2 on the 2x72: belt progressions for annealed and hardened stock, heat control, plate-quench flatness, and why A2 sharpens without diamonds.

2 min readWritten by Rich LinvilleFree to read

Good news first: A2 is one of the friendliest tool steels you will ever put on a 2×72. Its restrained carbide structure — the same trait that makes it tough — means it grinds cleanly, hand-sands honestly, and sharpens on ordinary stones. If D2 is the steel that fights back, A2 is the tool steel that cooperates.

Grinding Annealed A2

Annealed A2 hogs beautifully: fresh ceramic or zirconia belts in the 36–60 grit range move it fast with light pressure, and it profiles and drills without drama. Standard progression applies — set bevels coarse, refine through 120–220, and leave the edge dime-thick before heat treat. One planning note: A2 is a kiln steel (1750–1800°F soak, air or plate quench), so most makers grind closer to final shape pre-heat-treat than they would with a forgiving carbon steel — there is no torch-and-magnet fallback here (see the send-out option if you are kiln-less).

Near-profiled gray steel blank with four tang holes and rough bevels on a worn bench, a coarse abrasive belt beside it.

Grinding Hardened A2

At 58–62 HRC, A2 still grinds cooperatively — noticeably easier than D2 at the same hardness. Sharp belts and moderate speed are the whole recipe. The one caution is universal: heat. A 400–450°F temper means the edge’s temper margin is real but not generous — keep the blade moving, dip often, and slow the machine for post-heat-treat finishing passes. Variable speed earns its keep here (the case for it lives in the 2×72 buyer’s guide).

Gloved hand holds a gray knife blank by the tang, blade dipped in a clear pot of water on a dark bench.

Belt Progression

  • Hogging (annealed): 36–60 grit ceramic — fresh belts, light pressure, let the grit work
  • Bevel setting: 60–120 ceramic or zirconia
  • Refinement: 220–400 (A2 rewards a clean 400-grit belt finish that hand-sanding picks up easily)
  • Finishing: Trizact/structured abrasives or straight to hand sanding — A2 hand-finishes more cleanly than almost any tool steel, and takes a handsome satin
    Gloved hand draws a hard abrasive block along a blade clamped on a felt pad, leaving even lengthwise satin scratches.

Full belt-selection logic in the Belt Buyer’s Guide.

Sharpening A2

Here is A2’s quiet superpower: its modest chromium-carbide structure sharpens beautifully on ordinary abrasives — no diamond mandate like the vanadium PM steels. Aluminum-oxide and ceramic stones, belts, or guided systems all cut it cleanly, and it takes a genuinely fine, keen apex (part of why plane-iron makers love it). Field maintenance is easy: it strops back readily. Run 17–20° per side for hard-use blades, finer for kitchen work — full method in How to Sharpen a Knife. Being a ~5% chromium steel, wipe and oil after sharpening sessions — fresh-ground A2 rusts like the tool steel it is (a patina is a fine working finish for it).

Overhead view of gloved hands wiping a knife blade flat with a cloth on canvas, stone and plain oil tin behind.

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