I have a number of different sized insert boring bars from 1/4" to 1". Many with carbide shafts. I tend to do a lot of small diameter deep holes. The larger bars are held directly in the QCTP holders. The smaller ones are held with tool holders or collet chucks.
A number of years ago I bought a bunch of Sandvik solid carbide 6mm boring tools from a guy for dirt cheap. I use the Sandvik tool holder for that. Recently I bought a couple 7mm bars from Sandvik.
Here's my collection of my 6mm and 7mm solid carbide boring bars.
I decided to make a collar for it to use in an existing split block. I machined the part to the OD to fit the split block. Bored out the ID to almost 7mm. I made a brass lap and got it to exactly 7mm. I then split the collar to the length of the carbide bar with a slitting saw.
I then clamped a .275" pin gauge in the collar and into the split block so I could drill and tap to install an indexing hole in the collar so that the collar was oriented the same repeatedly.
If you look at the Sandvik boring bars, the rear section is tapered. This is so that by having a cross pin in the collar
, and puhing the bar to the rear, it orients the bar to the proper position. So now I can change boring bars and the tip height will always be the same.
A number of years ago I bought a bunch of Sandvik solid carbide 6mm boring tools from a guy for dirt cheap. I use the Sandvik tool holder for that. Recently I bought a couple 7mm bars from Sandvik.
Here's my collection of my 6mm and 7mm solid carbide boring bars.
I decided to make a collar for it to use in an existing split block. I machined the part to the OD to fit the split block. Bored out the ID to almost 7mm. I made a brass lap and got it to exactly 7mm. I then split the collar to the length of the carbide bar with a slitting saw.
I then clamped a .275" pin gauge in the collar and into the split block so I could drill and tap to install an indexing hole in the collar so that the collar was oriented the same repeatedly.
If you look at the Sandvik boring bars, the rear section is tapered. This is so that by having a cross pin in the collar
, and puhing the bar to the rear, it orients the bar to the proper position. So now I can change boring bars and the tip height will always be the same.
