Best way to cut mild steel sheets

[Y C LuiParticipant @yclui16187]

[Y C LuiParticipant @yclui16187]

The sheet is 2 mm thick. SAE-AISI 1018 cold roll. I need to cut out a plate taking the shape of several arcs combined so end mills is the only tool option for me. I have tried 2-flute 5 mm end mill which is OK but the amount of materials removed seems to be more than necessary. If I go for smaller diameter end mills, chip evacuation will be a problem. Will roughing end mills be better ? 4 flutes or 2 ( haven't seen such type ) ? what diameter and RPM will be optimum ?

[Paul LousickParticipant @paullousick59116]

I rough cut 2mm steel sheet with a thin blade in an angle grinder first then clean up on the mill.

[Thor 🇳🇴Participant @thor]

I would use a 2-flute cutter (slot drill), have you tried a 4mm? Might save a bit more material. I have usually farmed out such jobs to a Milling, Turning & Welding shop near me.

Thor

[JasonBModerator @jasonb]

You won't find much in the way of roughing cutters below 6mm and even if you found a 4mm one by the time you have left some material for a clean up cut with a standard cutter you will be removing almost as much as the 5mm.

4mm 3-flute carbide cutter would do, 5000rpm if you can, say 300mm/min feed. Blow chips away with compressed air or rig up a vacuum cleaner.

[Y C LuiParticipant @yclui16187]

Posted by JasonB on 26/05/2022 07:31:57:

4mm 3-flute carbide cutter would do, 5000rpm if you can, say 300mm/min feed. Blow chips away with compressed air or rig up a vacuum cleaner.

That is the cutting process I have been dreaming about but 5000rpm and 300mm/min feed is way outside the envelope of my 300 lb bench mill ( Emco FB2 )

It appears that even with appropriate cutter and machine it is still not possible to do a full-depth cut of 2 mm in one go as three passes were done in the video ( DOC was 0.7 mm in each pass ). Is that because of chip evacuation problems ?

I have got the idea of using roughing end mills because my 6 mm roughing end mill cuts slots ( DOC 3 mm ) in mild steel with significantly less effort compared with my regular mill of the same diameter. Furthermore, the chips produced are smaller which should help to avoid clogging.

Edited By Y C Lui on 26/05/2022 08:20:00

[jann westParticipant @jannwest71382]

seems like there's more ways to cut sheet steel than with a end mill … Plasma cutter, water jet, laser … google suggests that there are metal nibblers available from amazon that will do 2mm sheet steel.

[HopperParticipant @hopper]

Depends how big it is and how complex the shape is. But you could mark it out and cut it with a hacksaw, bandsaw, angle grinder etc then file it to final shape.

[John HaineParticipant @johnhaine32865]

Model Engineers Laser

[Dave HalfordParticipant @davehalford22513]

Supermarket Plasma cutter, leaves a 1mm cut line. Use a wooden template to guide the torch if like me you don't have a CNC equipped mill and an old metal biscuit tin underneath to catch the dross.

[Nick WheelerParticipant @nickwheeler]

curved cuts in 2mm steel would be a jigsaw job for me, as they're difficult to do with an angle grinder. Plasma cutter is good too.

You didn't say what they are for, which dictates the finish required.

[JasonBModerator @jasonb]

Posted by Y C Lui on 26/05/2022 06:26:20:

what diameter and RPM will be optimum ?

Why ask what the optimum RPM will be when you don't have a mill capable of running at the optimum speed, What do the makers of your cutters suggest? Most have charts that give a good starting point.

[Ady1Participant @ady1]

That's why I got a plasma cutter from Lidl, while groaning "Not ANOTHER 150 quid fer gawd sake!"

But they cut up to 12mm of steel in any direction you want more easily and quickly than anything us home shop people have ever been capable of before

[Nick Clarke 3Participant @nickclarke3]

Posted by Ady1 on 26/05/2022 09:49:35:

That's why I got a plasma cutter from Lidl, while groaning "Not ANOTHER 150 quid fer gawd sake!"

But they cut up to 12mm of steel in any direction you want more easily and quickly than anything us home shop people have ever been capable of before

+1

Nick

[Paul LousickParticipant @paullousick59116]

Lots of good suggestions for cutting the 2mm plate,. 5000 rpm mill, laser cutter, plasma cutter, etc, BUT how many model engineers with a basic home workshop have these tools or can afford to pay to have it done ? . I don't which is why I would rough cut it with an angle grinder and finish it on the mill.

Edited By Paul Lousick on 26/05/2022 10:34:19

[Y C LuiParticipant @yclui16187]

Posted by Paul Lousick on 26/05/2022 10:33:44:

Lots of good suggestions for cutting the 2mm plate,. 5000 rpm mill, laser cutter, plasma cutter, etc, BUT how many model engineers with a basic home workshop have these tools or can afford to pay to have it done ? . I don't which is why I would rough cut it with an angle grinder and finish it on the mill.

The fact is I don't even have an angle grinder because all the stuffs I made are rather small. The workpiece in the question is just 45 mm long / wide. I have tried dremel-like tool + cut-off wheels but the wheels break quite easily. Will seriously consider getting an angle grinder. Looks like a must-have.

[HopperParticipant @hopper]

Posted by Y C Lui on 26/05/2022 10:44:41:

The fact is …The workpiece in the question is just 45 mm long / wide.

Mini hacksaw and file. Easy peasy.

[jann westParticipant @jannwest71382]

"The workpiece in the question is just 45 mm long / wide."

DingDingDing we have a winner – for the single most essential piece of information, which took 15 comments before it was disclosed.

See Hopper's answer – mini hacksaw and file.

[Martin KyteParticipant @martinkyte99762]

Bandsaw or Jigsaw.

regards Martin

[Dave HalfordParticipant @davehalford22513]

Posted by Nick Clarke 3 on 26/05/2022 10:10:19:

Posted by Ady1 on 26/05/2022 09:49:35:

That's why I got a plasma cutter from Lidl, while groaning "Not ANOTHER 150 quid fer gawd sake!"

But they cut up to 12mm of steel in any direction you want more easily and quickly than anything us home shop people have ever been capable of before

+1

Nick

I got the £80 one

[Nick WheelerParticipant @nickwheeler]

Posted by Hopper on 26/05/2022 10:50:57:

Posted by Y C Lui on 26/05/2022 10:44:41:

The fact is …The workpiece in the question is just 45 mm long / wide.

Mini hacksaw and file. Easy peasy.

And takes about the same time as reading this thread

[Nigel Graham 2Participant @nigelgraham2]

I often resort to a hacksaw, so offer this tip:

Clamp the sheet flat on a suitable surface so you cut the steel at an angle, bringing more teeth to bear on the cut and reducing or preventing horrible vibration and noise.

[Richard MillingtonParticipant @richardmillington63972]

Jigsaw.

[Author]

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