# Homemade Boring Bar - Low Cost, Fun Project. Turn, Thread, Groove, Radius etc.



## BladesIIB (Apr 9, 2021)

Great first lathe project, or experienced machinist project. A tool you will always be able to use. A 1.5” Boring Bar made from 4140 and designed to fit on your Quick Change Tool Post in one of your existing tool holders. Will hold any 5/16” Brazed Carbide or HSS Tool bit. The design could also be easily modified to make a smaller boring bar like a 1” or ¾” bar to hold ¼” tool bits. Really fun to make and no critical tolerances to add stress.

This was a very cost effective boring bar for me especially since it can be used for turning, threading, grooving or radius cutting in a bore. Most insert boring bars will only hold one type of insert and buying a boring bar this size for each of those operations would get very expensive.

I don’t see this design around anymore. I used one like this 25 years ago with a big chunk of key stock welded on the side of a round bar to hold it. Cutting the slots seemed like a good upgrade to the design to integrate nicer with a Quick Change Tool Post tool holder.

I hope you get a chance to make one. Great opportunity to use your lathe and your mill. Try out tools like a slitting saw and just have some fun making some chips.


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## T Bredehoft (Apr 9, 2021)

I don't think I put a lead angle on them but I was making these in the 1970s.  I didn't use cemented carbide, I used HSS, easier to  grind, more readily available.


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## BladesIIB (Apr 9, 2021)

T Bredehoft said:


> I don't think I put a lead angle on them but I was making these in the 1970s.  I didn't use cemented carbide, I used HSS, easier to  grind, more readily available.


Yes an oldie but a goodie. Still as good a tool today as in the 70’s.


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## Ischgl99 (Apr 9, 2021)

I saw one of those I believe on a Cutting Edge Engineering video recently and wanted to make one, but his was something like 3” diameter.  A little big for my 12x36 lathe lol.  Thanks for showing how you did it, I am adding that to the project list.


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## BladesIIB (Apr 9, 2021)

Ischgl99 said:


> I saw one of those I believe on a Cutting Edge Engineering video recently and wanted to make one, but his was something like 3” diameter.  A little big for my 12x36 lathe lol.  Thanks for showing how you did it, I am adding that to the project list.


That is great to hear. Glad you have a new project idea.


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## mmcmdl (Apr 9, 2021)

T Bredehoft said:


> I don't think I put a lead angle on them but I was making these in the 1970s. I didn't use cemented carbide, I used HSS, easier to grind, more readily available.


True , by no means a new idea . If I don't have 100 or so of these down the basement I don't have one . We always made our tooling to be job specific and these things are simple to make however large or small . They also work great in the boring / facing heads .


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## Alcap (May 6, 2021)

To do a project coming up I’ll need to make a large boring bar like you made . Watching the video you had a unique tap handle , could you post about how you put that together? Maybe a new thread if needed Thanks


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## BladesIIB (May 6, 2021)

Alcap said:


> To do a project coming up I’ll need to make a large boring bar like you made . Watching the video you had a unique tap handle , could you post about how you put that together? Maybe a new thread if needed Thanks


Be sure to post some pics when you get your bar done. Here is a link to the Tap Handle. A shop in New Jersey makes them. I made a video of my hack to add the bearing and it is on another thread but I will post it below as well for you. http://northernmachininginc.com/?page_id=21


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## BladesIIB (May 6, 2021)

Video for how to modify the tap handle.


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## twhite (Jan 2, 2023)

Here are a few of my self made boring bars. The 2 on the upper left take square inserts. I made these in the 80’s. All others were made last year. Everede style, insertable internal thread and insert triangle. 3/4”,5/8”&1/2” diameters 

I also have some at work that take round blanks. The easiest type to make. 5 minutes and you have a boring bar. 







Cutting oil is my blood.


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## Janderso (Jan 4, 2023)

twhite said:


> Here are a few of my self made boring bars. The 2 on the upper left take square inserts. I made these in the 80’s. All others were made last year. Everede style, insertable internal thread and insert triangle. 3/4”,5/8”&1/2” diameters
> 
> I also have some at work that take round blanks. The easiest type to make. 5 minutes and you have a boring bar.
> 
> ...


Very nice!
Well done


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