13/64" x 3-5/8" Cobalt HSS-J/L Drill Bit Carts Use with putting compressed air

Use with putting compressed air into the spark plug hole to hold up valves

Release suction easily by lifting "lipped" edge

The diameter range is 6-1/2" to 14-1/4"

Also mounts test indicators with 1/4" post

13/64" x 3-5/8" Cobalt HSS-J/L Drill Bit Carts Use with putting compressed air13 64" x 3 5 8" Cobalt HSS J L Drill Bit Features and Benefits: Constructed of M 42 8% cobalt high speed steel for super abrasive resistance in tough metals Heavy duty spiral flute design produces faster chip ejection Shorter cutting lips reduce torque when drilling in high tensile strength materials 135 degree split point begins drilling immediately, minimizing bit walk