| name | sharpen-knife |
| locale | wenyan |
| source_locale | en |
| source_commit | 82c77053 |
| translator | Julius Brussee homage — caveman |
| translation_date | 2026-05-03 |
| description | Sharpen and maintain knives using whetstones, field stones, and improvised abrasives. Covers blade anatomy, bevel assessment, whetstone technique (coarse to fine progression), stropping, sharpness testing, field sharpening methods, and ongoing edge maintenance. Use when a knife fails the fingernail test, when cutting tasks require excessive pressure, before a trip where a sharp blade is essential, after heavy use, or when a blade has visible nicks or a rolled edge. Applicable to bushcraft blades, folding knives, and garden cutting tools.
|
| license | MIT |
| allowed-tools | Read |
| metadata | {"author":"Philipp Thoss","version":"1.0","domain":"bushcraft","complexity":"intermediate","language":"natural","tags":"bushcraft, knife, sharpening, blade, maintenance, whetstone, tools, gardening"} |
礪刃
以礪石、野石、權設之磨物，礪刃而養其鋒。
用時
- 刃輕觸指甲不咬乃用
- 切務須過力，斷處不齊乃用
- 將行而需利刃（雕、烹、劈）之前乃用
- 重用之後例維（依用，每一至三日為節）乃用
- 刃見缺、捲、崩乃用
入
- 必要：將礪之刃
- 必要：磨面（礪石、金剛板、瓷棒、野石）
- 可選：磨革（皮帶、紙板、滑木）並磨膏
- 可選：角規或硬幣以為斜面之參
- 可選：油筆以察斜面
- 可選：磨油或水（依石之類）
法
第一步：察刃
察刃以定礪之深淺。
Blade Assessment:
┌─────────────────────┬──────────────────────────────────┬─────────────────────┐
│ Condition │ Signs │ Action Needed │
├─────────────────────┼──────────────────────────────────┼─────────────────────┤
│ Dull (most common) │ Won't catch on fingernail; │ Medium grit → fine │
│ │ slides off tomato skin; │ grit → strop │
│ │ reflects light along edge │ │
├─────────────────────┼──────────────────────────────────┼─────────────────────┤
│ Very dull / abused │ Visible flat spot along edge; │ Coarse grit → │
│ │ tears rather than cuts; │ medium → fine → │
│ │ edge shines under light │ strop │
├─────────────────────┼──────────────────────────────────┼─────────────────────┤
│ Nicked / chipped │ Visible notches in edge; │ Coarse grit to │
│ │ snags on material when drawing │ grind past nicks → │
│ │ across │ reprofile → strop │
├─────────────────────┼──────────────────────────────────┼─────────────────────┤
│ Slightly dull │ Catches on fingernail but not │ Strop only (or a │
│ (maintenance) │ crisply; still cuts paper but │ few passes on fine │
│ │ not cleanly │ grit then strop) │
├─────────────────────┼──────────────────────────────────┼─────────────────────┤
│ Rolled edge │ Edge feels sharp on one side │ Strop firmly on │
│ │ but dull on the other; blade │ both sides; if that │
│ │ curves microscopically │ fails, light passes │
│ │ │ on fine stone │
└─────────────────────┴──────────────────────────────────┴─────────────────────┘
Light Test:
Hold the blade edge-on under a bright light. A sharp edge is invisible —
it has no width. A dull edge reflects a thin line of light where metal
has folded or flattened.
得：刃之狀已明，所須之礪粗細亦定。
敗則：若不能定，自中粗（一千目）始。後可細之，然初太粗則磨耗無謂之金。
第二步：識磨物
擇所宜之石。
Abrasive Types:
┌─────────────────────┬─────────────────────────────────┬──────────────────────┐
│ Type │ Characteristics │ Best For │
├─────────────────────┼─────────────────────────────────┼──────────────────────┤
│ Water stones │ Soak 5-15 min before use; │ Home sharpening; │
│ (natural/synthetic) │ fast cutting; wear quickly; │ best feedback and │
│ │ need flattening periodically │ finest edges │
├─────────────────────┼─────────────────────────────────┼──────────────────────┤
│ Diamond plates │ No soaking needed (use water │ Field use; hard │
│ │ as lubricant); very durable; │ steels; flattening │
│ │ aggressive cut │ water stones │
├─────────────────────┼─────────────────────────────────┼──────────────────────┤
│ Ceramic stones/rods │ No soaking; very fine grit; │ Touch-up and │
│ │ hard and slow-wearing │ maintenance; field │
│ │ │ carry │
├─────────────────────┼─────────────────────────────────┼──────────────────────┤
│ Oil stones │ Use honing oil; slower cutting; │ Traditional; │
│ (Arkansas, India) │ very durable; less messy │ workshop use │
├─────────────────────┼─────────────────────────────────┼──────────────────────┤
│ Field stones │ Any smooth, fine-grained stone; │ Wilderness emergency │
│ (improvised) │ river stones, slate, sandstone; │ when no other │
│ │ unpredictable grit │ abrasive available │
└─────────────────────┴─────────────────────────────────┴──────────────────────┘
Grit Progression:
220-400 → coarse → reprofile, remove chips, set new bevel
800-1000 → medium → standard sharpening of dull blade
3000-6000 → fine → refine edge, polish bevel
8000+ → ultra-fine → mirror polish, razors (optional)
得：磨物已擇，已備（浸、油、潤）。
敗則：若無正石，瓷杯之底（無釉之環）可權為細磨。車窗之邊亦然。野中，滑石勝於無物。
第三步：尋斜面之角而合之
斜面之角定刃之形。除重塑外，宜合舊角。
Common Bevel Angles:
- Bushcraft / fixed blade: 20-25° per side
- Kitchen knife: 15-20°
- Japanese kitchen: 10-15°
- Machete / chopper: 25-30°
- Folding knife (EDC): 20°
- Hori-hori / garden blade: 15-20°
Finding the Angle:
1. Lay blade flat on stone (0°)
2. Slowly raise spine until bevel sits flush
3. The flush point is the correct angle
4. Marker trick: ink the bevel, take one stroke
- Ink removed from whole bevel = correct
- Ink removed only at edge = too high
- Ink removed only at shoulder = too low
Coin Stack Reference (rough):
- 1 coin under spine ≈ 12-15°
- 2 coins ≈ 17-20°
- 3 coins ≈ 22-25°
得：可恆持一角而合舊斜面。
敗則：若徒手不能恆角，用導具或夾。角不恆者，礪敗之最常因也。先試廉刃，再施珍刃。
第四步：礪——自粗至細
由所須最粗者進至最細者。
Sharpening Technique:
SETUP:
1. Stone on stable, non-slip surface (wet towel underneath)
2. Stone fully saturated (water) or oiled (oil)
3. Position for smooth, controlled strokes
STROKE METHOD (per side):
1. Place blade at correct angle
2. Push edge forward as if slicing thin layer off surface —
heel to tip in sweeping arc
3. Maintain consistent pressure and angle
4. Light to moderate pressure — let abrasive work
5. 5-10 strokes per side, then alternate
ALTERNATING:
- 5-10 A → 5-10 B → repeat
- Approaching apex: 3 per side, then 1 per side alternating
CHECKING FOR BURR:
- After enough strokes, thin wire edge (burr) forms on opposite side
- Drag thumb ACROSS edge (never along), spine to edge
- Burr catches on side opposite to one being sharpened
- Burr means apex reached — switch sides
- Both sides burr-and-removed → next finer grit
PROGRESSION:
Coarse → burr both sides → medium
Medium → burr both sides → fine
Fine → light alternating → strop
得：終石之後，刃咬指甲固，切紙清淨（磨革之前略滯可也）。
敗則：若二十擊之上不起芒，察角——或太陡（磨於刃上），或太緩（磨刃之平）。再用油筆之術。若石塞（金屑壅之），洗而以校石或平板平之。
第五步：磨革其刃
磨革除餘芒，整刃如剃。
Stropping Protocol:
1. Use leather strop, smooth cardboard, or bare softwood
(palm side of leather belt works in field)
2. Apply stropping compound if available (chromium oxide, fine paste)
3. Lay blade flat at sharpening angle
4. Draw blade SPINE-FIRST (opposite of sharpening — drag edge backward)
5. Light pressure only — less than sharpening
6. Alternate sides: 5 → 3 → 1 → 1 → 1
7. Total: 20-30 strokes alternating
⚠️ CRITICAL: Strop spine-first (pull edge backward).
Pushing edge-first cuts the leather and dulls the blade.
Field Strop Alternatives:
- Smooth side of leather belt (hold taut)
- Cardboard or newspaper laid flat
- Palm of hand (very light, spine-first only)
- Smooth driftwood or flat of dry log
得：刃斷臂毛，切薄如電話簿之紙清淨，自重穿熟番茄。
敗則：若刃覺利而咬滯，餘芒在一側也。細石上再三五擊交替，再磨革。若仍不齊，或一側角差——以油筆驗而正之。
第六步：試其鋒
以漸進之試衡刃之質。
Sharpness Tests (easiest to most demanding):
1. FINGERNAIL TEST (basic):
Light draw across nail at 45°.
Sharp: catches and digs in
Dull: slides without catching
2. PAPER TEST (good):
Hold printer paper, slice down.
Sharp: clean cut, no tearing
Dull: tears, folds, won't start
3. TOMATO TEST (kitchen standard):
Place ripe tomato on board.
Sharp: blade weight alone starts cut
Dull: needs pressure to break skin
4. ARM HAIR TEST (very sharp):
Light draw across arm hair, no skin touch.
Sharp: hair pops cleanly
Not quite: hair bends or pushes aside
5. HANGING HAIR TEST (razor sharp):
Hold single hair, bring blade to it.
Razor: cuts with minimal pressure
Unnecessary for most bushcraft/garden use.
Sharpness Standards by Use:
- Bushcraft / camp: pass paper test
- Kitchen: pass tomato test
- Carving: pass arm hair test
- Garden (hori-hori): pass paper test
得：刃過所宜之試。
敗則：若過甲試而敗紙試，宜更礪於細石而多磨革。若甲試亦敗，回中粗，自第四步重礪。
第七步：野中之礪（無正石之法）
Field Expedient Sharpening:
RIVER STONES:
1. Find smooth, flat, fine-grained stone (slate, granite, basalt)
2. Wet surface
3. Same technique as Step 4 — angle, stroke, alternate
4. Won't polish but restores cutting ability
5. Slightly gritty feel preferred — glassy stones too slow
CERAMIC:
- Bottom of ceramic mug (unglazed ring) = fine hone
- Excellent for camp touch-ups
CAR WINDOW EDGE:
- Edge of car window (rolled down slightly) = fine ceramic
- 5-10 per side for quick touch-up
SANDPAPER ON FLAT:
- Place on flat log or rock, sharpen as on stone
- Works well
LEATHER BELT STROP:
- Always available if wearing belt
- Hold taut, strop spine-first
Minimum Field Kit:
- Small diamond plate (credit-card size) or ceramic rod
- Leather strop strip (10cm × 3cm, fits in sheath)
Almost no weight; handles all field needs.
得：刃復於足用之鋒，可任營中諸務。
敗則：若無磨物，硬木之平面摩細沙於紋中可權為粗磨。先求其用，後求其美。
第八步：常養其鋒
防勝於修。
Edge Maintenance Habits:
1. Strop before each use — 10 per side on leather/cardboard
(alone keeps knife sharp for weeks between stones)
2. Cut on wood, not stone, glass, ceramic, or metal
3. Never pry, twist, or use as screwdriver
4. Clean and dry after use — moisture corrodes, corrosion eats edge
5. Store in sheath, magnetic strip, or guard — never loose in drawer
6. Carbon steel: oil after cleaning (camellia, mineral)
7. Stainless: less, but still benefits from drying and oiling
Frequency:
- Daily kitchen: strop daily, stone weekly
- Weekend bushcraft: strop before trip, stone monthly
- Occasional garden: strop before use, stone seasonally
- Heavy field: strop daily, stone every 2-3 days
得：常養之法立，礪石之間，刃恆利。
敗則：若頻須自粗至細之全礪，或鋼太軟（換硬刃），或刃為誤用所傷（切硬面、側扭、銹蝕）。
驗
陷
- 角不恆：礪敗之最常者也。中途易角則圓刃而不利。以油筆驗，先慢後速。
- 力過：重壓不速礪——反槽石而崩刃。緩力足矣。
- 越粗細：自四百直跳六千則深紋猶在，細石不能除。各粗細宜消前者之紋。
- 不起芒：未起芒於兩面則未至刃尖，刃不利。芒乃節點，宜耐之。
- 磨革之刃前：推刃入革則革斷而刃捲。磨革必背先（拽刃後行）。
- 疏單斜之背：和式單斜刃僅磨斜面，然背平亦須輕擊以除芒。勿於背平起斜。
- 用誤之潤：水石用水，油石用油。混則塞。勿水於油石、油於水石。
參
make-fire — 礪刃為理引火、柴薪、羽柴所必需；火法與刃養相伴forage-plants — 利刃可清採而少傷草木maintain-hand-tools — 園刃（hori-hori、修枝剪）礪法相通；此技深於刃之專法
