RA系列超薄型交叉滾子軸承為THK交叉滾子軸承型號，其結構為外圈分半，內圈整體型，超薄型極限化的尺寸設計、有助于相關結構的輕薄化設計，內圈整體結構更適宜于內圈旋轉精度高的場合，穩定旋轉精度達微米級；適用于精密檢測儀器，一起人關節，直驅力矩馬達，高精度轉臺等要求高精度，高剛性的應用場合。
| THK code | d (mm) | D (mm) | B (mm) | Cr (kN) | Cor (kN) | Mass(kg) | IKO Code |
| RA5008 | 55 | 66 | 8 | 5.1 | 7.19 | 0.08 | CRBS508 |
| RA6008 | 60 | 76 | 8 | 5.68 | 8.68 | 0.09 | CRBS608 |
| RA7008 | 70 | 86 | 8 | 5.98 | 9.8 | 0.1 | CRBS708 |
| RA8008 | 80 | 96 | 8 | 6.37 | 11.3 | 0.11 | CRBS808 |
| RA9008 | 90 | 106 | 8 | 6.76 | 12.4 | 0.12 | CRBS908 |
| RA10008 | 100 | 116 | 8 | 7.15 | 13.9 | 0.14 | CRBS1008 |
| RA11008 | 110 | 126 | 8 | 7.45 | 15 | 0.15 | CRBS1108 |
| RA12008 | 120 | 136 | 8 | 7.84 | 16.5 | 0.17 | CRBS1208 |
| RA13008 | 130 | 146 | 8 | 7.94 | 17.6 | 0.18 | CRBS1308 |
| RA14008 | 140 | 156 | 8 | 8.33 | 19.1 | 0.19 | CRBS1408 |
| RA15008 | 150 | 166 | 8 | 8.82 | 20.6 | 0.2 | CRBS1508 |
| RA16013 | 160 | 186 | 13 | 23.3 | 44.9 | 0.59 | CRBS16013 |
| RA17013 | 170 | 196 | 13 | 23.5 | 46.5 | 0.64 | CRBS17013 |
| RA18013 | 180 | 206 | 13 | 24.5 | 49.8 | 0.68 | CRBS18013 |
| RA19013 | 190 | 216 | 13 | 24.9 | 51.5 | 0.69 | CRBS19013 |
| RA20013 | 200 | 226 | 13 | 25.8 | 54.7 | 0.71 | CRBS20013 |
