Hi all,
I often have need to put large holes into stainless steel and aluminum,
I have a boring head for my mill and a boring bar for the lathe.
To make a hole big enough for the boring bar to get into I have been using HSS jobber drills to take it out a bit at a time, For the boring head I have been plunging a milling cutter through first.
I get through a lot of drill bits doing this so I was thinking about getting some of the 'U' drills that take the replaceable inserts and would let me pump coolant into the hole at the same time.
I am really after some advice on: A - is this a cost-effective way of drilling or should I just invest in a set of colbolt drills,
B - How do you mount the indexable drill bits?
The lathe has a no.3 Morse Taper tail stock and the mill has a 3MT in the head stock.
The only holders I have seen (I am looking on ebay!) are BT40.
Also, I presume it will be simple enough to feed coolant when using them on the lathe (as the bit will remain still) but what about the mill?
There is coolant but not through the head. Do you get (or make) some sort of rotary adaptor or will the fact that the drill is vertical and coolant should fill the hole anyway be enough?
Many thanks!!