Grinding & Sharpening W1

W1 is the least demanding steel in the abrasives rack — it anneals dead soft, grinds like the simple steel it is, and sharpens on anything. Its shop quirks come from how it arrives (round drill rod as often as flat bar) and how it is hardened (often differentially, which changes the sanding story).

On the 2×72

Any sharp belt eats annealed W1; the interesting work is flattening rounds — forging drill rod to bar, then truing on the platen — and the usual thin-hard discipline after the quench at 60-64 HRC: sharp 120-220, light passes, cool hands. W1 through-hardens shallow, so aggressive post-HT grinding can genuinely grind through the hard case on thicker stock quenched slow — another argument for hogging annealed and finishing gently.

The Differential Wrinkle

Clay-quenched or edge-quenched W1 (its natural configuration, per the hamon guide) puts soft spine and hard edge on one blade — and they sand differently: the soft zone cuts faster and scratches deeper at every grit. Even pressure discipline, fresh paper, and the etch-polish ladder manage it; the reward is the quench line coming up bright. Budget the hamon finish like a second project.

At the Bench

Everything works — oilstones, waterstones, sandpaper on glass, the strop. W1 takes a violent edge fast and strops back instantly; angles 10-15 dps fine work, 15-20 field. This is the steel to LEARN freehand sharpening on: cheap, honest feedback, keen results — the same reasons it teaches heat treat so well.