Twin cutter boring heads

[Zumba]

Anyone use a twin cutter boring head? I see offerings from Criterion ($$$$$) and Gromax ($$).

I'm boring A36 steel for the most part, as well as some occasional durabar cast iron and stainless steel. I can't seem to get a good finish with my Criterion DBL202 and DBL203 boring heads because when I crank up the speed, vibrations result. If I slow it down, the finish sucks.

I'm hoping one of these twin boring heads will save the day.

[bluej_x]

Have you looked into Graflex twin cutter boring heads. Seco Carbaloy bought them out. We have excellent results with these on ASTM 536 Grade 50 which is much harder than A36. With the right grade insert stainless should be no problem. These also have optional insert holders that are offset about .010" in Z so you can use one to rough and the other to finish in the same pass.

Only drawback is the $$$$$$.

[laka]

With a twin boring head you can't pull the tool away from the bore wall to retract. You'd have to feed in and rapid/feed straight out.

[RICHARD ZASTROW]

Zumba, Try to google Davis boring blocks. They are made to fixed sizes and adjustable. Indexable and grind to size carbide. Hope that helps.

Dick Z