Extractor #91 for Bolt Sizes 1/4-5/16” use with 1/8” Drill Bit. - Extractor #92 for Bolt Size 3/8” use with 3/16” Drill Bit. - Extractor #93 for Bolt Size 7/16” use with 15/64” Drill Bit. - Extractor #94 for Bolt Sizes 1/2-9/16” use with 5/16” Drill Bit.