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aostling
09-21-2007, 06:52 PM
How did the nomenclature for lathe toolholders get established? According to Machining Fundamentals (1995), by J.R. Walker:


To tell the difference between right-hand and left-hand toolholders, hold the head of the tool in your hand and note the direction the shank points. The shank of the right-hand toolholder points to the right, the left-hand toolholder points to the left

This would make sense if we typically picked up a toolholder by the head (bit) end, but since we don't, the nomenclature seems backwards. What's the rationale?

tattoomike68
09-21-2007, 07:00 PM
Iv had to mill some super hard tool holders so they would fit to the job and not hit the spindle.

I dont know the hardness but it was case hardend and done right. (inner steel was not soft)

If you need to jig up a toolholder use a hot saw and eat it up , some dont machine easy if at all.

BadDog
09-21-2007, 07:01 PM
To me, it's just the side the tool starts on. Left hand tool starts on the left. Right hand tool starts on the right. No idea the original, but that's how I remember it.

aostling
09-21-2007, 07:37 PM
To me, it's just the side the tool starts on. Left hand tool starts on the left. Right hand tool starts on the right. No idea the original, but that's how I remember it.

This makes sense. I'll try to remember it: "a left-cutting tool goes into a left-handed toolholder, which bends to the right."

alcova
09-21-2007, 08:28 PM
It was explained to me this way, hold your hands in front of yourself and the way the wrist bends the easiest is how holders are named...ie left hand bends easiest to the right & right hand bends easiest to the left, so that goes along with BAD DOG's explanation

alcova

aostling
09-21-2007, 09:59 PM
It was explained to me this way, hold your hands in front of yourself and the way the wrist bends the easiest is how holders are named...ie left hand bends easiest to the right & right hand bends easiest to the left, so that goes along with BAD DOG's explanation
alcova

Thanks, this is just the sort of mnemonic I needed.

darryl
09-22-2007, 02:11 PM
Now you got us all standing if front of the lathe wiggling our hands. :)

Carld
09-22-2007, 08:08 PM
A straight tool holder can't get the tool bit right up to the chuck jaws. However, a right hand tool holder will place the tool bit near the chuck jaws. The same is true when turning toward the tailstock you need to use a left hand holder.

Don't ponder over what they are called, just use what does the job.

The tool bits are described the same as the holders are.

aostling
12-05-2007, 11:56 PM
It was explained to me this way, hold your hands in front of yourself and the way the wrist bends the easiest is how holders are named...ie left hand bends easiest to the right & right hand bends easiest to the left

Just when I thought I had this subject mastered, I bought this Armstrong cut-off toolholder from eBay. I made a mistake -- it's the wrong size for my 6" Atlas. But the seller was not at fault.

As you can see by the two toolholders in the foreground, Armstrong uses "R" and "L" after the part number to designate a right-hand or a left-hand toolholder. But the cut-off toolholder, which is left-hand, is labeled "R." Why?

http://i168.photobucket.com/albums/u183/aostling/DSC01822.jpg

J. Randall
12-06-2007, 01:21 AM
Carld, its to late to go out and look tonight, but I believe all of mine that will get you close to the chuck have an L on them . The ones that will get you close to tailstock have an R. I have always kept it straight in my head as being the direction you are going to cut. I will try and think to look tomorrow.
James

Lew Hartswick
12-06-2007, 08:45 AM
Allan. It makes sense if the cutoff is to get close to to the chuck it
should have the same designation as the turning tool holder that
does the same thing. ie. R . Yes?????
...lew...

Bguns
12-06-2007, 08:54 AM
http://www.armstrongtools.com/catalog/products.jsp?groupID=201

PS Armstrong calls it a R hand tool also....