9 mm Wide Mouth Screw Thread Vials for HPLC and GC - Chrom Tech. The 9 mm wide mouth screw thread vials are our most popular and recommended These vials are autosampler-compatible and offer a 40% larger opening than Vials and caps - Separations. GC and HPLC autosampler vials with screw neck N 8, N 9, 8.2 x 40 mm ...