An inch-size bearing, 1/4 in bore × 1/2 in outer × 3/16 in wide, the most common size in premium spinners.
What it is
R188 is a standard inch-series ball bearing size: 1/4 in (6.35 mm) bore, 1/2 in (12.7 mm) outside diameter and 3/16 in (4.76 mm) width. It is compact enough for small spinners, coins and rings.
Why it matters
Many interchangeable spinner buttons and parts are made for R188, so the size alone tells you a lot about compatibility. Ball count, material, shielding and lubrication still decide how it actually spins and sounds.
Also known as: R188, R188 Bearing Size, R188轴承.
是什么
R188 是标准英制球轴承尺寸：内径 1/4 英寸（6.35 mm）、外径 1/2 英寸（12.7 mm）、宽 3/16 英寸（4.76 mm），足够紧凑，适合小型陀螺、响币和转环。
为什么重要
很多可互换的陀螺按钮和配件都按 R188 设计，所以尺寸本身就能说明不少兼容信息。但实际转动和声音，仍取决于珠数、材质、防尘方式和润滑。
又称：R188、R188 Bearing Size、R188轴承。
