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View Full Version : Can you use hacksaw blades as parting tools?



abn
09-21-2003, 11:48 PM
One of the things I found in the tooling drawers of my South Bend was a variety of old hacksaw blade lengths ground on the tips like cutting tools...the only thing I can figure is that the previous owner used these as parting tools or something. I guess I could fab a holder and see if it works but I figured I'd better check here before I go making something (else) that doesn't work.

Evan
09-21-2003, 11:55 PM
I use a hacksaw blade as a parting tool all the time. Stop the lathe, put it in back gear to hold it steady, Saw the %%^& off. Then finish the cut surface. Ya don't always have to use the cutoff tool.

Thrud
09-21-2003, 11:59 PM
abn:
That is how you learn - try something until it works or you get pissed off and try something else. It is the scientific way - the trick is in knowing it is hopeless and moving on. http://bbs.homeshopmachinist.net//biggrin.gif

abn
09-21-2003, 11:59 PM
Darn that was a quick response...I do the same. I just wonder what the assortment of ground hacksaw blades was used for, thought I might be missing out on an old timer's trick or something.


<font face="Verdana, Arial" size="2">Originally posted by Evan:
I use a hacksaw blade as a parting tool all the time. Stop the lathe, put it in back gear to hold it steady, Saw the %%^& off. Then finish the cut surface. Ya don't always have to use the cutoff tool.</font>

Al Messer
09-22-2003, 12:21 AM
In one of the British publications geared toward the amatuer machinist, I recall seeing a sketch of a "parting tool" that used a piece of a hacksaw blade to do the cutting. The idea was to reduce waste in a piece of stock. I've never tried it for myself.

darryl
09-22-2003, 12:34 AM
I usually run the lathe at slow speed, and slowly saw with the hacksaw, just to help clear the chips. For me, it's easier and quicker than a cut-off blade.
FWIW, I came across some surplus Disston hacksaw blades- among the best cutting I have used.
Ah, but you said pieces of hacksaw blades. Of course, there's no side relief to them, so they tend to jam, also they are usually too thin to stay on spot. Can be done, though, especially if the cut is not deep.

[This message has been edited by darryl (edited 09-21-2003).]

dnsbss
09-22-2003, 10:25 AM
Maybe they were used to make narrow grooves.

Evan
09-22-2003, 12:17 PM
Darryl,

I sometimes will run the lathe at slow speed while sawing but I don't like it if there is a possibilty of the hacksaw jamming in the cut.

gglines
09-22-2003, 10:14 PM
Using a hacksaw in a lathe is punishable by death in some shops. I would make sure you cover the lathe ways to protect them from the saw.

George

Evan
09-23-2003, 02:05 AM
That's what the piece of plywood is for.

Thrud
09-23-2003, 03:01 AM
Evan:
No, that is what a properly adjusted cut-off tool is for.

It is dangerous to use a hacksaw while a lathe is running, plus it should not be near a lathe anyway.

The hack saw plades may have been used to groove a piston (like a cut-off tool) for a steam engine or for e-clips on a shaft.

darryl
09-23-2003, 04:01 AM
I agree with all the safety concerns raised about hacksawing with lathe running. In hindsight, I shouldn't have suggested it, my apologies.

Cass
09-23-2003, 03:40 PM
I have used razor blades for cut off tools when the workpiece was 0.005" wall thickness plastic tubing. Using a hacksaw blade as a cut off tool should work fine on the right material, could be it was foam plastic or summer sausage. Lathes get used for all kinds of things other than metal. The tools from Thinbit work very nicely and a hacksaw blade might be used in a similar way for grooves and cut off.

rebelsqk
09-25-2003, 02:14 PM
A saw-z-all blade works pretty well. They are a bit thicker so are less flexible. They come in all sorts of sizes, shapes an thicknesses as well.
Grind the teeth till they are just gone. Many blades being bi-metal leaving some HSS will give you a better tool. Grind to the shape you want. Then lightly tap the cutting edge a few times with an hammer. This will give you small amount of side clearance that will allow the tool to work much better. Hone the edge with a stone before use.

Oso
09-25-2003, 06:28 PM
About sawing with the lathe running.....

I betcha nearly everyone who said it was unsafe has done it this year themselves........do as I say, not as I do........

Evan
09-25-2003, 07:54 PM
Incidentally, the piece of plywood is mainly for changing the chucks with my arthritic fingers, as well as for hacksawing.

jim k
09-25-2003, 08:12 PM
I use a porta- bandsaw.Works great.

docsteve66
09-25-2003, 10:18 PM
Oso: just between you, me and a gate post, I did it this week, but i will not confess to any one else.
Steve

Thrud
09-26-2003, 01:42 AM
<font face="Verdana, Arial" size="2">Originally posted by Oso:
About sawing with the lathe running.....

I betcha nearly everyone who said it was unsafe has done it this year themselves........do as I say, not as I do........</font>

Never. Had a great teacher.

Al Messer
09-27-2003, 10:35 AM
Well, I'll confess that sometimes I do, with a piece of a board covering the ways. Reason for this is when I'm making multiple parts, and since I don't have a multi-toolholder set up on the toolpost, I don't like all the extra time it takes to change tool holders. I usually use the saw with the spindle rotating until the piece is cut about half-way through, then I turn off the lathe, lock the spindle and finish by hand. One of these days, I'm going to fit a proper tool bit holder to it so I can progress towards 20th Century technology.

David Hafnorske
09-27-2003, 02:05 PM
I like Thrud had a good teacher. NEVER saw with the lathe running. If the blade breaks it is a great way to slit your wrists. As far as the old hacksaw pieces they may be the remnants of an experiment gone bad. I had the same idea once too. didn't work. i'm reminded of it every time i see the holder in the scrap heap.

darryl
09-28-2003, 05:46 AM
Of course, I never hacksaw with the lathe running, even though I was the one to first suggest it here. Ya. Anyway, I had an idea. Cut is down if that's what it deserves. Here goes. What is taught about hacksawing is to not drag the blade backwards in the cut, but to take the pressure off before pulling back, then saw forward again, etc. Well, with the lathe running, you can maintain pressure on the blade, while 'sawing' back and forth, and the work is always progressing into the teeth, as long as the surface speed in the cut is faster than your rate of backing up the hacksaw. Jim k's idea of using a porta bandsaw led me to the idea of the older method of cutting stock, with a reciprocating blade, motor driven. Why not recreate this as an accessory, mounted to a parallel way fixed to the rear of the bed? It would move along this way, be clamped where you need it, you lower the blade onto the work, and it oscillates away until it cuts off the piece, then hits a switch and shuts itself off, just like a regular bandsaw. The lathe is running at a speed that ensures the work always has a forward motion into the teeth, until the piece is nearly cut off. It would have a damper so the blade would drop at a slow rate, and when not in use, just lift it up, out of the way. Most cutting off is done close to the chuck, so the accessory wouldn't need much traverse on it's way, in fact, that extra way could be usable for other accessories, none of which are coming to me at the moment, however. That's that, the other thing that occured to me is why not make a custom cutoff tool holder that mounts to the lathe's ways, and has it's own leadscrew, and a standard cuttoff blade and holder. There's likely a way to make it quickly mountable and removeable. You never need angles anyway, and you wouldn't have to disturb the toolpost. Maybe it could 'hinge' in from a rear mounted, semi-permanent mount. Cutoff from the rear has its advantages.
Just some ideas. Laundry should be my idea at the moment, but I'm avoiding that.