How to machine a hole on a lathe?

[OHJEEZE]

Drilling to the largest diameter you have available then boring to size is proper!

With jaws reversed, not much meat is in the chuck! Can be a bad idea to attempt using parting tool without tailstock and center support on other end. Can end badly with your workpiece exiting the chuck unwantingly!

Sawing is much safer in a situation like that!

 

[264killer]

If you got a grove made with parting tool use a band saw that cuts straight. Saw about 1 inch deep, rotate only enough that the sawblade is partly in the cut. Repeat till you have 2 haves.

 

[Profreedomokie]

What rpm are you turning when using your parting tool. I found 50 to 75 rpm works pretty well. Like it was stated earlier you want the cutting edge just a hair below center.

 

[Perplexed]

What rpm are you turning when using your parting tool. I found 50 to 75 rpm works pretty well. Like it was stated earlier you want the cutting edge just a hair below center.

50 to 75 rpm?? My lathe won’t even run that slow. I usually turn off aluminum between 600 and 800 rpm, and set the tool dead even using a leveling guide.

 

[Ahall]

Watch your surface feet per minute on larger diameter parts.

Boring is probably the practical approach in a home shop.

There are special tools made for drilling a core out of a part, but those are typically economical when you're making a pile of parts and can use the cores for something else. They resemble hole saws and parting tools with a curved blade that matches the core diameter.

Like others have said, flip the chuck jaws around and get a deeper grip on the part.
Space the part off of the chuck or don't bore all the way through.
If your are worried about the jaws deforming the part, not boring through, and facing off the cap at the end is a good approach.

With a big hole, you have a lot of leverage to pry the part out of the jaws when cutting.

If you have a 6 jaw chuck, that's nicer for thin wall material,

Parting - slow cuts, good tool alignment and a blade that is ground to cut straight are all needed. Don't make parting cuts any deeper than necessary.

 

[Schlafftablett]

If you don’t have a boring bar of the right size and you have one, you can also fudge a “boring bar” by using a 2 flute end mill. Put it in your tool holder and give it the SLIGHTEST angle to keep the body of the tool from hitting. It’s not great but it’s saved me a couple times.

 

[SlugSlinger]

Thanks for the help everyone.

I got them bored and cleaned up.

Now just need some drilling and tapping the holes.

These are housings for some surface mount lights I’m going to bolt to the front bumper of the Jeep.

 

[SlugSlinger]

Final product.

 

[eaglerjs]

looks damn good

 

[SlugSlinger]

looks damn good

Thank you sir!