Ring/groove boring bar?

[slowneasy]

Video man, nice! I had something just like that in mind. You have a set screw coming in from the end of the bar?

I really need to get a grinder on a pedestal set up to grind HSS

 

[Video_man]

Video man, nice! I had something just like that in mind. You have a set screw coming in from the end of the bar?

I really need to get a grinder on a pedestal set up to grind HSS

Yes, that's how they are made. This is one of a set of assorted sizes I bought over 20 years ago, but I assume they are still available. Actually should not be too hard to make, using a round toolbit rather than the square one to avoid having to deal with a square hole. You could use a small dowel pin or old drill bit shank for a one-off toolbit, even.

 

[mickri]

I found that it is much easier to grind tool bits using a belt sander verses a bench grinder. I have a Delta 1x42. I struggled with my bench grinder. Since I got the belt sander I can now grind any shape tool bit that I need.

My boring bars are like what Video man posted except the set screw is in the top of the bar over the tool bit. This allows the the bit to be closer to the end of the bar if you need to get to the bottom of a blind hole.

Several ways to cut the slot/hole. Mr Pete has a video on how to mill a square hole. I recall that the Machinery's Handbook also touches on the subject. There was a thread a while back about making boring bars that you might find helpful. https://www.hobby-machinist.com/thr...-project-turn-thread-groove-radius-etc.92026/

 

[Jimsehr]

I know I can grind a tool to cut that groove in a very short time . I think poster said it would be better out of carbide. I would silver solder a carbide tip on a 1/2 bar and grind it to the .035 wide groove tool. I don’t think I could do it on my belt sander out of carbide or hss. Much as iI like using the belt sander to sharpen hss.
If poster wants I’ll grind the tool for him and lend it to him for postage. Back and forth.
And I don’t think once the deeper snap ring would ever have to be removed once installed. The front snap ring is all that is needed to load and unload the tungsten
piece into the bore.
If slowneasy wants me to make tool let me know.

 

[slowneasy]

Jimsehr, you are very generous, much appreciate the offer. I did order the ThinBit tool and believe this should work. If it doesn't for whatever reason, I will be contacting you. Thank you!

 

[epanzella]

Just make one from O1 steel. Turn the profile you want then mill half of it away. This will leave you with a front and rear cutter so grind one of them away for small bore clearance. Then heat red hot and quench in oil. I don't bother with temper. The attached pix are for an internal threading bar but you get the idea. I keep a hunk of O1 around and can make just about any cutter I want in 20 minutes. The edge holds up well as long as you don't overheat it. I built 2 rifles with the pictured cutter and it's still sharp.

 

[Illinoyance]

Micro 100

 

[slowneasy]

Illioyance, Micro 100 was the first place I looked. They didn't offer anything in their standard listing that provided the depth I needed. They offer a lot of good tooling but not this time unfortunately. I went with the ThinBit setup.

 

[Illinoyance]

Search Micro 100 on eBay.

 

[Jimsehr]

Illioyance, Micro 100 was the first place I looked. They didn't offer anything in their standard listing that provided the depth I needed. They offer a lot of good tooling but not this time unfortunately. I went with the ThinBit setup.

I went an looked in my tool box for solid carbide bore bars that I have made over the years. Some are over 15 years old. Some have had the tips broken off and had new tips added.