7 Pc Fractional R8 Collet Set 1/8" to 7/8" High Precision for Bridgeport 7 Piece Our Part # ALL-41048 High precison 7 piece set includes 1/8-7/8" x 1/8" R8 collets Made of high grade tool steel. Hardened and precision ground. Threaded internally 7/16"-20 Guaranteed T.I.R. 0.0005"