Need a boring bar

Enigmaticul

Enigmaticul

Banned
I am trying to find a boring bar that can bore at a minimum a .380 hole to install joint pins. I am very overwhelmed by the options out there. What is a decent cheap boring bar?

Much appreciated.
 
There is a member here that sells a terrific solid carbide .250, 6" boring bar. Unfortunately he doesn't donate them and there not real cheap.


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Why do you feel that you need to bore that hole........ ???

I drill mine with a 3 flute solid carbide 5/16 drill to the bottom and then drill the hole the length of the pin barrel with a W drill............... never had a problem.


Kim
 
You don't want a boring bar with a minimum of .380 bore for installing pins unless you are installing 1/2" diameter pins. If this is for a joint pin with the .382 (or so) alignment barrel, you would never be able to nail the bore diameter with a .380 minimum bore tool. You need a .250 minimum bore to take an intermediate cut after drilling and then measure without risking overshooting the diameter. A 5/16" boring bar would probably be OK, but 1/4" would be more versatile.

Decent and cheap rarely exists in tooling. Grinding your own is the decent and cheap option.
 
Enigmaticul said:
I am trying to find a boring bar that can bore at a minimum a .380 hole to install joint pins. I am very overwhelmed by the options out there. What is a decent cheap boring bar?

Much appreciated.
Click to expand...
You want a boring bar that is less than a .380 hole if that is the desired size you are wanting to achieve on the final size hole. ALWAYS drill a smaller size hole and bore to correct size to make the hole concentric. If you absolutely need to drill a hole then start with the boring bar for a guide to keep the drill from wandering. I would highly recommend gage pins for sizing the holes as well. Drill bits will and do wander.
 
You can get away with a. .290" minimum bore brazed carbide boring bar.
Step drill to .300" then bore to .308-.312 depending on your 3/8 pin.
.380 is not your minimum as already mentioned . That's the barrel size which
is about 1.200 deep.
If you mount a good router horizontally on your lathe, you can use a 1/4 ball
end mill.
 
If you can drill a straight hole, then why not drill 3/8" & then run a .382" reamer? No sense in over complicating things.

Don't get me wrong, there's nothing wrong with boring. For me, personally, often being absent minded, I am fairly certain that I would screw up from time to time. Not only is boring any two holes exactly the same very difficult, but knowing me I would sometimes bore the hole too large & screw everything up. Knowing me like I do, I found it was much easier and always exactly accurate, almost fool proof, if I simply drill a slightly undersize hole then ream to size. The only thing I have to get right is drilling a straight hole, which is elementary machine work. The reamer makes the hole dead nuts every single time. Food for thought.
 
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