Description Warranty Information Precise R-8 End Mill Holders (8 Piece Set) - R8E-8S 8 piece set includes sizes: 3/16", 3/8", 1/2", 5/8", 3/;4", 7/8", 1" & 1-1/4". Made of alloy forged steel for long, durable service life. Hardened and ground to ensure maximum accuracy. R-8 End Mill Holders 8 Piece Set