Rounded nipples are the enemy of wheel truing, and they almost always come from a sloppy-fitting wrench. The Park Tool SW-1 Spoke Wrench avoids that problem by using a precision-stamped opening sized to 3.30mm (0.130") wrench flats, which grips all 4 sides of the spoke nipple instead of just 2. That full-contact fit means you can tension spokes without the wrench slipping or chewing up the nipple corners, which is what happens with cheap stamped triangle wrenches or worn-out multi-size tools.

The wrench body is heat-treated steel with a nickel-plated finish to resist corrosion and maintain the tool interface over time. A green vinyl dip covers the handle area, which does double duty: it gives you grip and tactile feedback, and it identifies the 3.30mm size at a glance. Park Tool color-codes each wrench in their SW lineup differently, so if you keep multiple sizes in your toolbox or saddle bag, you can grab the right one without checking.

One thing to know about this specific size: the 3.30mm nipple is typically found on older American-made bicycles, including vintage Schwinn models and wheels built with Union or Torrington spokes. It is not as common on modern bikes. If you are not sure what size your nipples are, measure across the wrench flats with a caliper before ordering. Spoke gauge and nipple size are not correlated, so the diameter of the spoke itself will not tell you which wrench to buy. The SW-0 (black, 3.23mm) handles most modern nipples from DT Swiss, Sapim, Wheelsmith, and Pillar, while the SW-2 (red, 3.45mm) covers a lot of entry-level and department store wheels. The SW-1 fills the gap between those 2 sizes, so make sure you are buying the one that actually matches your nipples.