hacksaw cutting slowly

Hi. I saw a message posted to this group by someone saying that he
can cut 1 square inch of soft steel cross section in 60 seconds. That
sounded pretty fast to me, and I decided to give it a try. I was able
to cut about half a square inch of steel bar in about 30 minutes.
This is with a regular Craftsman hacksaw with a good blade. I am
using a large vise which holds the work steadily. I used a small
amount of gear oil in the kerf. The saw is cutting (I can feel it
bite on the cutting stroke), and filings are coming out. Actually, a
1/2 inch square cut is quite a bit of filings. But this is
approximately 1/60th the rate that the newsgroup post alluded to. I
thought that I should be at least within a factor of 10. The steel
that I am using is part of a bracket, and it cuts easily with a file
(no skate).
I know that an expert computer programmer can program 60 times faster
than a beginner, and get paid 10 times as much, but computer software
is a strange animal. I would think that I should be able to get
within a factor of 10. The blade wasn't buckling, so I think that a
high-tension hacksaw would not give all that much of a boost. It may
improve cutting speed by a factor of 3.
So, how does one cut a square inch of steel in 60 seconds? Inches do
matter!
Thanks,
Eric
Reply to
Eric Chang
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Your blade probably has too many teeth to get a bite into the steel with your available down pressure. It isn't a linear affect. 10 to 14 tpi is a better bet for 1/2".
The rule about not pushing down, just letting the blade do the work may apply to wood but not steel.
At risk of the thread going OT, the Craftsman aspect may part of the problem :-)
Bob
Reply to
Bob Powell
Gear oil is an extreme pressure lubricant. Don't use it for cutting. Use a cutting fluid like lard oil.
Use the best HSS blade you can find, with coarse enough teeth.
Jim
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Reply to
jim rozen
Definetly doing *something* wrong, as last week I cut through an annealed torsion bar in a few minutes... that's 1-1/8" or so round! Dulled my blade though...can't cut crap with it anymore... must finish power hacksaw project....
Tim
-- "I have misplaced my pants." - Homer Simpson | Electronics, - - - - - - - - - - - - - - - - - - - - - - --+ Metalcasting and Games:
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Reply to
Tim Williams
I wonder how many of us could actually cut a 1" square piece of steel in one minute with a hand saw. I know if I tried, I would be winded, and probably would run overtime.
Reply to
Leo Lichtman
Hell, it takes me a least 2-3 minutes to cut off a 1 inch diameter steel rod in my lathe spinning at high speed with a new, sharp hacksaw blade. By the time it's done, I'm breathing hard, cussing, sweating, etc.
Mike Eberlein
Leo Lichtman wrote:
Reply to
mikee
Strike a bloody light! I'd almost forgotten how painful a power hacksaw is.
6 to 10 *seconds* would be about right to get through a one inch square steel bar using my Brobo cold cut-off saw - plus, the finish on the cut ends is "milled" super-smooth.
Power hacksaws? Weld a steel loop on them, and donate them to a local boat owner.
Jeff
Reply to
A.Gent
One of the (many) things guaranteed to set me off is seeing a student cutting stock in a lathe as you describe. I believe that it is extremely dangerous and downright foolish.
Of course in your shop you may do as you wish but in mine it is verboten!
Errol Groff Instructor, Machine Tool Department H.H. Ellis Tech 613 Upper Maple Street Danielson, CT 06239
860 774 8511 x1811
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Reply to
Errol Groff
As Errol suggests, this practice seems very dangerous. Further, it seems very slow. Parting tools are made for this application and are very capable when used correctly.
I understand that most HSM's are not *really* concerned with how every 15sec period of their day is spent, but parting is so much easier....
As for the hacksaw, it's almost certainly the blade being the wrong tpi (and if it's dulling, buy a better blade - Starrett makes nice bimetal blades). At work we do a lot of bench work. I use a 14tpi blade for cutting anything including or larger than 1/8". I'd say 60sec for 1in square is perhaps pushing it, but 120sec is ample time. Yes, it's a lot of work, but that's why we have electricity.
Regards,
Robin
Reply to
Robin S.
So, how do you do internal cuts? Your cold saw can't get in there, breaking and rewelding a bandsaw blade is a pain, but it is simple to thread a power hacksaw blade through a starter hole. Works with hand hacksaws too, if the frame is large enough.
BTW, my favorite hand hacksaw is a big sturdy bow frame (3 to 4 feet long) with a length of bandsaw blade used as the hacksaw blade. Long strokes, cuts quick, and you can really crank in some tension on the blade to help it cut true.
Gary
Reply to
Gary Coffman
Yep. True. But: In the past 25 years I could count the number of times I've needed to do that on one hand. And then, I'd use a hand hacksaw.
But point taken.
Thing is, though, when I used to use a power hacksaw, I'd typically set it up and then go and then go and do something else for a while. With the cold cutoff, I set it up, cut, and its done.
The former is relaxing, but frustrating. The latter is no less relaxing, and immensely satisfying.
Clearance can be a pain for some cuts too, I'll admit. And short pieces.
Wowsers. Same here, but for wood, not metal. I really like my big old home-made wood bowsaw (with rope tensioner).
Jeff
Reply to
A.Gent
"mikee" writes in message news: snipped-for-privacy@charter.net... at some future date...
Hi guys! I'm typing this with one hand because the lathe ripped my arm off...
Reply to
PR
Just for grins after reading this thread I grabbed a 1 1/8" piece of square steel, and hacksawed it through with a hand hacksaw, wimpy frame and a used 18 tpi 10" long blade. Took ~2.5 minutes. I then took the same stock and put it in the old benchtop power hacksaw I have with a 14 tpi 12" blade. The machine took ~6 minutes running at 90 strokes a minute. The machine strokes about 5" per stroke, I stroked about 9" per stroke and about the same speed, with a coupla short breaks . After the machine was done cutting I did notice that I was puffing a lot less than when doing it by hand. lg no neat sig line
Reply to
larry g
news: snipped-for-privacy@charter.net...
surely Mikee is jesting(?). what exactly is the method? unless you are running the crossfeed you will be dulling teeth almost instantly. maybe that is why he sweats? --Loren
Reply to
Loren A. Coe

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