10" Class 300 Flange Bolt Kit ASTM A307 Grade A Zinc$0.00PriceOut of StockComplete Class 300 flange bolt kit for 10" ASME B16.5 flanges. Contents: (16) 1"-8 × 6-1/4" ASTM A307 Grade A Zinc-Plated Hex Machine Bolts and (16) 1"-8 Zinc Finish Hex Nuts.