Few Quick Questions...

[fterh]

I bought a stainless steel travel mug.. it's double-walled so I think after cutting it should have two parts...

[fterh]

OMG I NEED HELP!

I tried to mark out a line to cut.. after marking out I used my dad's hacksaw and that thing keep veering left and right. and the marker ink got rubbed off but the steel doesn't have even a scratch How do u cut stainless steel?

[larry cottrill]

Make sure you use a NEW hacksaw blade and take it slow. Once you get the cut started, cut all the way AROUND the piece, NOT across it. It might help to notch the line before you start the cut with the sharp corner of a small half-round file.

Your hacksaw cuts on the FORWARD stroke (if you have the blade mounted correctly!). Start the cut, then continue the cut TOWARD you as you work your way around, rotating the piece gradually AWAY from you as you go. Stainless work is not easy, you have to try something, observe what works, and develop your technique accordingly. When drilling, it is good to use a LITTLE heavy thread-cutting oil on the tip of the drill. The same might help with sawing, but maybe not -- I used my saw dry. It really dulls blades quickly, though, especially if you try to take it too fast. One of the problems with stainless is that the heat stays right there, building up as you work.

L Cottrill

[Mark]

I like to buy bi-metal hacksaw blades and for thin metal the more teeth per inch on your blade the less it will bite and grab your work. It's all about the teeth and yes if your blade is worn down it doesn't cut very well, except at either end where the teeth are usually not as dulled as the center teeth. ha
A tiny bit of oil might help too. A medium or fine toothed blade should be OK. If you are sawing bar stock, you want less teeth per inch.

[Mike Everman]

I use a composite blade in a radial saw. To heck with all that elbow grease!

[fterh]

Make sure you use a NEW hacksaw blade and take it slow. Once you get the cut started, cut all the way AROUND the piece, NOT across it. It might help to notch the line before you start the cut with the sharp corner of a small half-round file.

Your hacksaw cuts on the FORWARD stroke (if you have the blade mounted correctly!). Start the cut, then continue the cut TOWARD you as you work your way around, rotating the piece gradually AWAY from you as you go. Stainless work is not easy, you have to try something, observe what works, and develop your technique accordingly. When drilling, it is good to use a LITTLE heavy thread-cutting oil on the tip of the drill. The same might help with sawing, but maybe not -- I used my saw dry. It really dulls blades quickly, though, especially if you try to take it too fast. One of the problems with stainless is that the heat stays right there, building up as you work.

L Cottrill

For my mug the curve is more gradual so I have to cut a lot for the diffuser to fit with the nozzle.. and then cut off the remaining part again

I use a permanent marker to mark out the line, a piece of cardboard with the straight edge against the line to align my hacksaw. I can't really cut around it, since I have no clamp to hold it.

And you're saying that the hacksaw cuts on the forward stroke but I should cut towards me (backward stroke) by rotating the mug away? So it won't cut?

Hm, so I guess giving all I have into the blade and sawing like 5 strokes in one second won't help. And it's not like after 15 mins of 5 strokes per second there's a cut. There isn't even a damn scratch!

[larry cottrill]

I use a permanent marker to mark out the line, a piece of cardboard with the straight edge against the line to align my hacksaw. I can't really cut around it, since I have no clamp to hold it.

I didn't clamp mine hard, either. I just used the vise jaws as a "friction rest" to steady it - just enough to keep it from rotating when I didn't want it to.

And you're saying that the hacksaw cuts on the forward stroke but I should cut towards me (backward stroke) by rotating the mug away? So it won't cut?

Well, I agree my description wasn't too clear. What I'm saying is, you DON'T cut clear ACROSS the curve (like sawing through heavy pipe); you only cut down the NEAR side, until you get all the way round. Each forward stroke cuts a bit, then after you cut down a little, you rotate the piece away a little to bring the new steel up, so you can keep cutting around. You don't try to cut THROUGH the section, but AROUND the circumference. That's all I'm saying.

Hm, so I guess giving all I have into the blade and sawing like 5 strokes in one second won't help. And it's not like after 15 mins of 5 strokes per second there's a cut. There isn't even a damn scratch!

That would be about the right speed, or even a bit slower. It's the sharpness of the blade that does it, not the muscle you put into it. NOTE: If you start out by making a deep scratch with the edge of a file, you will be AMAZED at how the saw (a NEW blade) grabs hold and starts to cut! I guarantee you, a sharp file will NOT be intimidated by the stainless, although you may still have to use a "guide" to keep it on line as you file the scratch. It doesn't need to be much of a scratch -- just wide enough to accept the width of the blade will do.

L Cottrill

[fterh]

Well, I agree my description wasn't too clear. What I'm saying is, you DON'T cut clear ACROSS the curve (like sawing through heavy pipe); you only cut down the NEAR side, until you get all the way round. Each forward stroke cuts a bit, then after you cut down a little, you rotate the piece away a little to bring the new steel up, so you can keep cutting around. You don't try to cut THROUGH the section, but AROUND the circumference. That's all I'm saying.

I think I understand. You're saying I cut the side near to me, then when there's a cut instead of sawing through the whole thing, I rotate the mug and start on the new, uncut steel, then rotate again and repeat.

[larry cottrill]

Exactly. You just "inch your way around" until you've completed the cut. The last little bit is difficult, because of the instability of the almost-cut sections that are no longer fully locked together.

L Cottrill

[fterh]

Exactly. You just "inch your way around" until you've completed the cut. The last little bit is difficult, because of the instability of the almost-cut sections that are no longer fully locked together.

L Cottrill

Okay I bought a saw that can cut metal (according to the storekeeper) and some diamond files to scratch out the "notch". Hope it works!

[sockmonkey]

Exactly. You just "inch your way around" until you've completed the cut. The last little bit is difficult, because of the instability of the almost-cut sections that are no longer fully locked together.

L Cottrill

When you get close to that last bit you might also want to sitck a piece of something thin into the cut and ductape the halves together to keep things from flopping around.

[fterh]

Okay I cut 2 inches in an hour last night but it's sort of crooked.

Oh god it's damn hard to cut it straight though I have a line drawn there to guide the cut. I think 1/2 inch will be wasted, the remaining 1.5inches can be fixed by using JB weld I hope :S

[Jutte]

Make sure you have the correct tension on your blade as well - enough
tension that it 'rings' when you 'pluck' it .
Or you can use a angle grinder with a thin cutting disk...( my choice LOL)
Or a really meaty pair of tin snip cutters - although that depends
on how thick your stainless cup is.
I had to cut out a HEAP of stainless steel for hydrogen production plants once
and reccomend the angle grinder/disk method and for just keeping
the sanity of ones mind.
Yes... we could've have used a laser cutter...but we of course didn't have
one ...so it was the hacksaw or the angle grinder...so...and the rest is history...LOL!

[Mike Everman]

Hey fterh, can you not borrow a Dremel tool and get some cutoff wheels?

[fterh]

Okay this is beautiful. After the first crooked cut, I start again on another fresh area of steel.

Now I have like 3inches of straight cut. It's beautiful.