bor bar milling holder 18mm

[atlas1302]

Hallo, I have a n 18 mm bore bar milling holder for my Ferm 350 lathe. Now i am confused about which cutter tool to use a right handed or a left handed tool.
Google says right handed, but when I look at thephoto on the sit , the tools are lefthanded.

Which one should I get, and pleas provide a reasoned explanation as to why.

Thank you kindly,

[Muzzer]

The boring head is threaded onto the arbor with a normal right hand thread, so it can only be used with a normal clockwise spindle direction (when viewed from above). That means the boring bar will need to be a RH tool, so that the insert sticks out and travels in the correct direction.

It's difficult to explain this clearly in words but here's an example of how it's used and what the bars look like. I've not visited this site before but it seems to illustrate typical practice:
https://johnfsworkshop.org/home/proc...e-boring-head/

Hope this helps.

[atlas1302]

Thanks. I believe a right-handed chisel goes from the inside out, so towards the opening.
So with a bore head, you have to go from the outside in, otherwise it won't work. In that case, I think you need a left-handed chisel.
That is just my logic, of course, but I also heard somewhere that a left-handed chisel is suitable for this.

I already have a right-handed one, so I bought a left-handed one to go with it. I never use left-handed chisels, because when turning you usually go from right to left. Turning out a hole is therefore done in mirror image.

If I am completely wrong, I would naturally like to hear about it; we learn something new every day.

[Muzzer]

Well, if you are using a boring head to turn the outside diameter of a part, you'd need to use a left hand boring bar. If you are boring out an internal hole, you'd need a right hand boring bar. There are some boring heads that can also do facing of the end of a part but this product is not that kind.

I'd say it's unusual to use a boring head to turn an external diameter, which is why I think you will usually find that the boring bars supplied or recommended are right hand. I would tend to use a milling cutter for external surfaces, rather than a boring head, especially if you have a CNC milling machine, or using a rotary table if you only have a manual milling machine.

Boring heads have only a single point cutter, so they are very slow means of removing material. And they aren't very rigid, so are not suited to heavy cuts. The main reason for using a boring head is when the finished surface needs to be a precise cylindrical surface eg for a bearing or an engine cylinder bore.