Fisch - Adjustable Countersink Bit 1/8" - 5/16" D x 1-3/8" OAL
5pcs Metal Countersink Drill Bit Set for Wood, Metal, Steel, Mill Drill Bit Set Size is 1/4” 3/8” 1/2” 5/8” 3/4”with High Speed Steel, 82 Degree, 5 Flute, 6mm Round Shank, Carrying Case - Amazon.com
Countersink Drill Bit for 3/8" Tap
amoolo Single End Countersink Bit, Cobalt Steel Countersink Drill Bit with TiAlN Coating Finish for Hard Metal, 82 Degree Point Angle, 3/8” Round Shank, 1/2” Body Diameter - Amazon.com
55763 | 3/8 x 90 deg Three Flute Carbide Countersink - ARCH Cutting Tools
55212 Carbide Tipped Countersink #12 Screw 15/32 Dia x 7/32 Drill Dia x 3/8 Round Shank