Sherline now manufactures its own inserted tip carbide boring tool holders. They are available individually as an 80° holder (P/N 2259) or a 55° holder (P/N 2260). The pair of both holders is P/N 2261.
Each comes with a carbide insert, hold-down screw and special Torx key. The 3/8" round shank is held in a P/N 7600 tool post. The 2260 holder accepts a 55° insert and requires a minimum hole size of 3/4". The 2259 holder accepts an 80° holder and fits into a minimum hole size of 1/2".
In addition to fitting into a smaller hole, the 80° insert offers a little more strength, while the 55° insert will cut into a sharper corner.
The holders are made from case hardened steel with a black oxide finish. A flat is ground on one side so the two hold-down screws of the 7600 tool post can tighten against it to keep the tool from rotating.
Overall length of the holder is 3-1/4", and with both hold-down screws engaged it can be extended to bore a hole a little over 2" deep. Because the further the tool is extended from the tool post, the greater the tool flex, the tool should be extended no more than is necessary to bore the hole you need. Longer boring tools are offered by other manufacturers, but due to tool flex, Sherline does not recommend extending them more than about 2" from the tool post, so their extra length is of little value. Tool flex in a boring operation can result in a poor finish, boring a tapered hole or, in the worst case, an insert to bite in and break.
2260 Sherline Insert Boring Tool 80° holder Instructions
Using Carbide Iserted Tip Tools Instructions
CA Prop 65 WARNING: Drilling, sawing, sanding or machining wood products can expose you to wood dust, a substance know to the State of California to cause cancer. Avoid inhaling wood dust or use dust mask or other safeguards for personal protection.
I can do all this through him who gives me strength. Philippians 4:13