Is diamond knife sharpener profitable to sell on Amazon United States?

The niche generates $298K/yr across 63 tracked products. 3 of 3 products launched in the last 360 days are still selling. 90-day search growth is -0.4%. Flapen's verdict: Worth a look (57/100).

How competitive is the diamond knife sharpener niche?

26 brands and 129 sellers compete. The top 5 products take 28% of clicks and top 5 brands hold 71% of demand.

What do buyers complain about in diamond knife sharpener?

Top complaints mined from reviews: Sharpness, Durability, Quality-Overall. The return rate is 1.8%.

When does demand for diamond knife sharpener peak?

Demand peaks in Dec; the busiest month runs 2.0× the quietest.

What does it cost to enter the diamond knife sharpener niche?

Listings span $6.39–$146.76; the average listing price is $42.32 (sweet spot $15–$100). The average incumbent carries 1,980 reviews — the moat a new listing must climb.

diamond knife sharpener

Worth a look

Shows a sweet-spot price point ($42.32 avg), but a failed launch gate (market size, growth, or returns) keeps it on the watch list.

Avg price

Incredible$42.32

avg listing price — sweet spot $15–$100

Competition

Great28%

top-5 click share — an open shelf

Returns

Great1.8%

return rate — above 5% kills the launch gate

Price range

Good$6.39–$146.76

cheapest to priciest tracked listing — scored on the share inside $15–$100

Brand share

Good71%

top-5 brand share — brands hold most of the demand

Market size

Good$298K

$298K/yr · 197K searches

Conversion

Okay3.6%

search→purchase rate — share of searches ending in a sale

Review moat

Okay1,979.56

avg incumbent reviews — the moat a new listing must climb

Quality gap

Okay4.5★

avg incumbent rating — lower means beatable quality

Growth

Bad-0.4%

90-day search growth — must beat 0% to launch

According to Flapen's Amazon United States niche tracking, diamond knife sharpener is a $298K/yr Amazon United States market (197K searches/yr). The top 5 brands hold 71% of demand. Demand peaks in Dec. Verdict: Worth a look — 57/100.

Data updated Jul 29, 2026 · scored weekly · How we score niches

diamond knife sharpener market data

Units sold / yr: 6K–8K; avg 0–100/product
Revenue / yr: $254K–$339K; units × avg price
Conversion rate: 3.6%
Avg BSR: #685
Page quality: 0%
Prime: 100%
Sponsored: 73%
Out of stock: 0.0%
Avg brand age: 51 months
Avg seller age: 170 days

Competition & brand share

Clicks spread well past the top 5 (28% combined) — an open shelf where new products get seen.

Brands

26 rising

Sellers

129

Top-5 brand share

71%

Top 20: 97%

Top-5 click share

28%

Top 20: 67%

Open market

25%

DMT (Diamond Machining Technology)44%
SHARPAL9%
EZE-LAP8%
Smith's5%
XILEWHZF5%
Kota Japan4%

Demand & seasonality

Weekly Amazon search volume, last 104 weeks — -0.4% search growth over the last 90 days.

Peak months: Dec · busiest ÷ quietest = 2.0×

Open Trend

Top diamond knife sharpener search terms

diamond knife sharpener70K/yr -3.6%2.7% conv.
dmt diamond sharpening stone47K/yr +3.4%1.9% conv.
diamond sharpener24K/yr +8.2%1.9% conv.
knife sharpener diamond10K/yr +16.9%1.7% conv.
dmt knife sharpener9K/yr +28.1%2.1% conv.
diamond hone8K/yr -17.0%4.2% conv.
eze lap diamond stone9K/yr -23.8%2.8% conv.
dmt sharpening stone8K/yr +10.9%1.5% conv.
eze lap diamond sharpener3K/yr +30.8%4.7% conv.
eze-lap2K/yr +9.9%2.8% conv.

All search terms

Top diamond knife sharpener products on Amazon

Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.

Beatable (≤4.3★) Contested Strong incumbent (>4.7★)

All 24 tracked products in this niche — three views at once, no toggling.

Top sellers

by 90-day click share

DMT D8F Dia-Sharp Bench Stone - Diamond Knife Sharpener for the Workshop Jobsite or Kitchen - Fine - Flat Diamond Sharpening - Non-Slip Knife Sharpener- Made in the USA - 8 x 3 x 0.38 Inches

DMT (Diamond Machining Technology)$39.724.5★1,130 rev

DMT FWFC DuoSharp Double-Sided Diamond Sharpening Stone for Knives and More 8-Inch Fine/Coarse White

DMT (Diamond Machining Technology)$25.064.6★1,383 rev

Smiths DCS4 4 Diamond Combination Sharpener - Double Sided Stone - Outdoor Field Knife Sharpener - Fish Hook & Pointed Tools Micro Sharpener - Lightweight Compact Handheld

Smith's$19.114.6★3,450 rev

DMT Deluxe Diamond Professional Knife Sharpening Kit - Includes Set of 3 Diamond Whetstone Blocks for Kitchen Knives Lawn Mower Blades Hunting/Butchery Tools and More - Comes in Natural Wood Box

DMT (Diamond Machining Technology)$104.064.5★1,766 rev

2 Pcs 400/600 Grit Portable Handheld Double Sided Sharpener Pocket Diamond Knife Sharpening Stone for Kitchen Garden Outdoor tools Fine/Coarse Grinding Black/Orange

XILEWHZF$10.064.6★593 rev

Newest

by launch date

Diamond Sharpening Steel - 12 inch Knife Sharpener for Master Chef Ideal for Kitchen Knife Cooking Knife Butchers and Japanese Knife Home Gourmet Blade Sharpening Stick

W WITHLENT$18.5082 rev

11mo ago

5 PCS Diamond Sharpening Stone Diamond Sharpening Plate

Okxiri$12.48161 rev

1y ago

Diamond Sharpening Stone Kit 3 Side Grit 400/1000/8000 Knife Sharpener for Sharp Blade Premium Diamond & Ceramic Whetstone with Angle Guide Non-Slip Base & Leather Strop

DOWOX$37.55290 rev

2y ago

Diamond Sharpening Stone 400/1000 Grit Handheld Double-Sided Diamond Sharpener 5 in 1 Honeycomb Surface Knife Sharpener Plate Whetstone with Ceramic & Tungsten Steel Scissor Slot for Kitchen Outdoor

Lifeholic$16.33408 rev

3y ago

2 Pcs 400/600 Grit Portable Handheld Double Sided Sharpener Pocket Diamond Knife Sharpening Stone for Kitchen Garden Outdoor tools Fine/Coarse Grinding Black/Orange

XILEWHZF$10.06593 rev

5y ago

What buyers say about diamond knife sharpener

What buyers praise and complain about, mined from review topics.

What buyers love

Sharpness31%

“Razor sharp”

Ease Of Use13%

“easy to carry”

Quality-Overall12%

“The build quality is excellent—very solid”

Value For Money9%

“Money well spent”

Advertised Vs Actual Product4%

“Exactly what I needed”

Efficiency3%

“Works Really Well”

Precision Of Cut3%

“Fast cutting, excellent for sharpening blades”

Durability3%

“Durable, easy to clean”

Instructions/User Manual/Troubleshooting2%

“instructions included”

Design-Overall2%

“with an elegant design”

What buyers complain about

Sharpness21%

“Not very sharp”

Durability10%

“doesn't last”

Quality-Overall9%

“Horrible quality”

Functionality-Overall6%

“Didnt work well”

Value For Money5%

“Too expensive”

Size-Overall4%

“it would not fit”

Ease Of Use3%

“Not as easy as it looks”

Material Quality2%

“The center of the stone has lost all abrasive material”

Instructions/User Manual/Troubleshooting2%

“Instructions aren't very helpful”

Strength2%

“not to the point of feeling flimsy”

Top return reasons

Sharpness43%

Functionality-Overall13%

Size-Overall9%

Advertised Vs Actual Product8%

Product Condition6%

Value For Money5%

Quality-Overall3%

Mechanism Issues2%

Ease Of Use1%

Durability1%

Common questions

Is diamond knife sharpener profitable to sell on Amazon United States?: The niche generates $298K/yr across 63 tracked products. 3 of 3 products launched in the last 360 days are still selling. 90-day search growth is -0.4%. Flapen's verdict: Worth a look (57/100).
How competitive is the diamond knife sharpener niche?: 26 brands and 129 sellers compete. The top 5 products take 28% of clicks and top 5 brands hold 71% of demand.
What do buyers complain about in diamond knife sharpener?: Top complaints mined from reviews: Sharpness, Durability, Quality-Overall. The return rate is 1.8%.
When does demand for diamond knife sharpener peak?: Demand peaks in Dec; the busiest month runs 2.0× the quietest.
What does it cost to enter the diamond knife sharpener niche?: Listings span $6.39–$146.76; the average listing price is $42.32 (sweet spot $15–$100). The average incumbent carries 1,980 reviews — the moat a new listing must climb.