
Park Tool SW-16 Square Spoke Wrench 3.2mm Internal Aero Rim Tool
Park Tool SW-16 Square Spoke Wrench 3.2mm Internal Aero Rim Tool
Stage 21 Bikes
23582 Moulton Parkway
#111
Laguna Woods CA 92637
United States
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Park Tool SW-16 Square Spoke Wrench – 3.2mm
The Park Tool SW-16 Square Spoke Wrench is purpose-built for wheels that use internal square spoke nipples, commonly found on modern deep-section aero rims. Its extra-long socket design easily reaches nipples hidden inside rims up to 50mm deep, making it an essential tool for carbon road wheels, aero gravel wheels, and performance wheelsets.
The ergonomically designed screwdriver-style handle provides excellent leverage, control, and comfort—allowing precise spoke tension adjustments without damaging nipples or rims.
Key Features & Benefits
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3.2mm square nipple compatibility
Designed specifically for internal square spoke nipples -
Deep rim reach
Extra-long 3.25" (8.5 cm) socket reaches nipples inside rims up to 50mm deep -
Aero rim specific
Ideal for modern deep-section carbon and aluminum wheels -
Screwdriver-style handle
Ergonomic grip offers superior control and torque -
Precision-machined socket
Ensures secure engagement to prevent rounding or damage -
Park Tool professional quality
Built for daily shop use and long-term reliability
Compatibility
✔ Spoke Nipples:
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3.2mm square internal nipples
✔ Wheel Types:
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Deep-section aero road wheels
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Carbon and aluminum rims with internal nipples
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Rims up to 50mm depth
⚠️ Note: Always confirm nipple size before use.
Technical Specifications
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Model: SW-16
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Nipple Size: 3.2mm (square)
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Reach Length: 3.25 in / 8.5 cm
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Handle Type: Ergonomic screwdriver grip
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Application: Internal spoke nipples
Recommended Uses
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Truing deep-section aero wheels
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Tensioning internal spoke nipples
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Carbon road and gravel wheel service
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Professional bike shop and home workshop use
Why Choose Park Tool?
Park Tool tools are the gold standard in bicycle service—trusted by professional mechanics worldwide. The SW-16 delivers precision, durability, and ease of use for today’s aero wheel designs.


