21mm socket
Skip itPrices mostly outside the sweet spot ($4.88–$14.44) — this niche doesn't clear our bar today.
Conversion
Incredible13.0%search→purchase rate — share of searches ending in a sale
Returns
Great1.8%return rate — above 6% kills the launch gate
Brand share
Okay77%top-5 brand share — brands hold most of the demand
Growth
Okay+15.4%90-day search growth — must beat 0% to launch
Review moat
Okay2,121.21avg incumbent reviews — the moat a new listing must climb
Competition
Okay61%top-5 click share — leaders hold, buyers still browse
Market size
Okay$139K$139K/yr · 123K searches
Avg price
Bad$8.75avg listing price — sweet spot $15–$100
Quality gap
Bad4.8★avg incumbent rating — lower means beatable quality
Price range
Bad$4.88–$14.44cheapest to priciest tracked listing — scored on the share inside $15–$100
Competition
The top 5 products take 61% of clicks — established leaders, but buyers still shop beyond them.Brands
12 falling
Sellers
18
Top-5 brand share
77%
Open market
18%
- TEKTON41%
- ZOYAKKI12%
- TIGHTSPOT12%
- ATOOLMIC6%
- EGOFIX6%
- JU JIAN TEC5%
- Open — no brand owns it (6 brands, 18%)
Product shelf
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
All 19 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
TEKTON 1/2 Inch Drive x 21 mm Deep 6-Point Impact Socket | SID23121
TEKTON$8.004.8★4,208 rev
ZOYAKKI 1/2 Drive x 21 mm Deep 6 PT Impact Socket CR-MO 1/2-inch Drive 6 Point Axle Nut Socket for Easy Removal of Axle Shaft Nuts (Metric 21MM)
ZOYAKKI$7.464.8★1,846 rev
TEKTON 1/2 Inch Drive x 21 mm Deep 6-Point Socket | SHD23121
TEKTON$6.994.8★8,501 rev
ATOOLMIC 1/2 Inch Drive x 21mm Impact Socket Metric Deep Socket 6 PT CR-MO for Easy Removal of Axle Nut (21mm)
ATOOLMIC$5.794.8★218 rev
TEKTON 1/2 Inch Drive x 21 mm Shallow 6-Point Socket | SHD22121
TEKTON$6.284.8★8,501 rev
Newest
by launch date
WORKPRO 1/2 Drive Lug Nut Impact Duty Socket 21mm Deep Thin Wall Socket Made of Premium Cr-Mo Steel Non-Marring Lug Nut Wheel Sockets for Car
WORKPRO$9.29395 rev
JU JIAN TEC 1/2 Inch Drive - 21mm Deep Impact Socket with Anti-Rounding 6 Point Design Heat-Treated Cr-Mo Steel Automotive Truck Maintenance Heavy Equipment Repair
JU JIAN TEC$8.0576 rev
BOEN 21mm 1/2 Drive Wheel Protector Impact Socket Non-Marring Lug Nut Thin Wall Deep Socket Set Chrome-Molybdenum Steel 6 Point Color-Coded Protective Socket
boen$11.52144 rev
TIGHTSPOT 1/2 Inch Drive 21 mm Deep Impact Socket with Anti-Rounding 6 Point Design Heat-Treated CRV Steel
TIGHTSPOT$12.63526 rev
EGOFIX 1/2 Drive Deep Impact Socket 21mm Socket CR-MO Metric 6 Point
EGOFIX$6.621,154 rev
Trending
90-day click momentum
ZOYAKKI 4-Piece 1/2 Inch Drive Impact Socket Set CR-MO Steel 6-Point Deep Socket Metric 17-19-21-22mm Hexagon Deep Socket Set with Storage Box for Repair Mechanic Garage
ZOYAKKI$14.444.7★
JU JIAN TEC 1/2 Inch Drive - 21mm Deep Impact Socket with Anti-Rounding 6 Point Design Heat-Treated Cr-Mo Steel Automotive Truck Maintenance Heavy Equipment Repair
JU JIAN TEC$8.054.8★
TIGHTSPOT 1/2 Inch Drive - 21mm Shallow Impact Socket with Anti-Rounding 6 Point Design Heat-Treated CRV Steel Metric
TIGHTSPOT$9.854.7★
WORKPRO 1/2 Drive Lug Nut Impact Duty Socket 21mm Deep Thin Wall Socket Made of Premium Cr-Mo Steel Non-Marring Lug Nut Wheel Sockets for Car
WORKPRO$9.294.5★
TIGHTSPOT 1/2 Inch Drive 21 mm Deep Impact Socket with Anti-Rounding 6 Point Design Heat-Treated CRV Steel
TIGHTSPOT$12.634.8★
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — +15.4% search growth over the last 90 days.No pronounced peak months · busiest ÷ quietest = 1.3×
Reviews
What buyers praise and complain about, mined from review topics.What buyers love
“This tool has old school quality”
“Handy socket”
“The size is accurate”
“definitely worth buying”
“Worked as advertised”
“Solid tools”
“The perfect socket for my 2020 Mazda Miata ND Club”
“Good material good product”
“Overall, the quality and durability are very good”
“Ease of use”
What buyers complain about
“Broke after a couple uses”
“It would not fit”
“Junk”
“Some of the old ones were showing rust”
“Not exactly as pictured”
“Very thin wall”
“This is not a reinforced socket”
“Cheap quality materials”