Boring Head

J

Jonathans

Professional Fish Killer
H-M Supporter Gold Member
Joined
Sep 24, 2014
Messages
209
I have a ZAY7032G mill. It's a central machinery gear head r8.
I have a job where I need to bore a 1 47/64" hole in 1" steel plate, so I think its time to purchase a boring head.
Are the Shars type junk or ok? What diameter do you think my machine can handle. 2", 3"?
I see some sets come with grazed carbide bars, and others have different indexable cutters.
If not Shars, what should I be searching for on ebay?
Thanks
 
Last edited:
I've owned the Chinese boring heads, and while they work OK, the adjustments aren't that accurate. I decided to buy nothing but American-made heads from now on. I now have a Criterion 1 1/2", and a Bridgeport # 1 which goes out to 2", and more with the right tool. I'm still watching for a good deal on a Bridgeport, or other 3" head.
Jim
 
The machine should be able to handle it. I did a 3" hole in 3/4" steel on my SX2, and that machine is pretty tiny. I would suggest removing the bulk of the material with a hole saw or by chain drilling before you start with the boring head, otherwise you will be there forever.

As far as the quality of the import boring heads, I have no direct experience, I built my own. When I did the 3" hole I didn't have a boring head; I actually used a fly cutter. They are difficult to adjust, but can be quite accurate.
 
If you get an import head and you find the adjustments not to be accurate. You can always set up dail inicator on a mag base on your table. Then with the machine in neutral, rotate the boring head agianst it to set zero. Then make your adjustment and recheck. But remeber if you move .010" on the indicator, you will be taking .010" a side or .020" off the diameter of the hole.

Im no familiar with your machine, but as long as you limit the amount of material you take at once you should be good. Also if yiu get to be doing even larger hole, check out trepanning.
 
I ended up with a Criterion DBL 202B boring head. I also picked up a 7/8"d stubby bar stepped down to 1/2" to fit the head. The bar comes with a TPGB321 insert.
Again, I will be boring a 1 27/64 through hole 1" deep in mild steel that will be threaded to 1 1/2" 12tpi. The work piece is too large for my lathe.
Would I be better off with a different insert ?
 
I wouldn't think the diameter would be a problem. You may need to take light cuts and lower RPMs as the hole gets bigger.

The Best with your project
 
Thanks guys. The Criterion is excellent
 
You must log in or register to reply here.
Back
Top