DMT FWFC Diafold: problems, parts and running costs

Checked: 2026-10-17

Summary

The FWFC is a folding two-sided diamond sharpener with a coarse 45 micron side and a fine 25 micron side, small enough for a pocket or toolbox. The usual complaints are that it cannot sharpen serrations or recurves, the 0.88 in. stone is narrow on large blades, and the coarse side is aggressive for routine maintenance. There are no consumables, so running costs are near zero, and it is a better buy below the $51.99 DMT direct price.

Common problems and fixes

Narrow stone — the stone is 0.88 in. wide, which limits the sharpening surface and is awkward on large blades. [2]
Coarse side too aggressive for maintenance — Reddit owners report the coarse side suits dull or damaged edges while the fine side handles maintenance, and one owner switched to the Fine/Extra-Fine variant after finding the coarse side too aggressive. [6][7]
Wears over time and is not replaceable — the diamond surface wears with use and there are no user-serviceable parts; normal diamond wear is not covered by DMT’s warranty. [5]
Heavy hand rounds edges fast — diamond cuts quickly, so a heavy hand rounds teeth quickly, a caution for the related Diafold Serrated. [9]

Parts and consumables

Diamond stone — not replaceable; when the surface wears out the tool is done, and no user-serviceable parts exist. [5]
Magna-Guide guided system — sold separately at $67.99 from DMT’s online store; it is an optional accessory, not a consumable. [3]

No oil or flattening consumables are needed: the stone can be used dry or with water. [1]

Yearly running cost

Not enough data for a yearly figure. There are no consumables beyond occasional cleaning and no oil is required, so recurring costs are close to zero; no owner-reported yearly spend was found. [1]

When it is a good buy

DMT lists the FWFC at $51.99, a premium over generic diamond stones that buys a long market history and a US-made plate. KnifeWorks lists a related Diafold in Fine/Extra-Fine at $39.99 on sale, and the BladeReviews.com reviewer paid about $25 back in 2017, so the price has climbed. Wirecutter’s 2025 knife sharpener guide does not cover this product and recommends electric sharpeners for home cooks and water stones for hand-sharpening enthusiasts; water stones need flattening and soaking, so the Diafold suits people who want a portable, low-maintenance tool. If you only touch up already-keen edges, the Fine/Extra-Fine variant is the better fit. [4][8][10]