Bevel for 18g Stainless Steel

[shizyo]

Hi, I am cutting some 1.2mm(approx 18g) stainless steel signs and the worst edge is 18-20 degree bevel as seen in the photos. Is it normal or you guys can cut 1.2mm stainless steel with better bevel? What degree will you expect with 1.2mm thickness? Thanks.

[adbuch]

I can't tell much from your photos. Perhaps post them at a much higher resolution. Is the bevel the same all the way around the part? What plasma cutter are you using? Under normal circumstances, the side angularity (bevel) decreases as the material thickness increases. Some of the causes of excess positive bevel (where the top of the part is smaller than the bottom) are worn consumables (particularly a worn nozzle), cutting too far away from the part (cut height too high), cutting speed too high, or current setting too low. If you have excess negative bevel then you may be cutting too close to the part, cutting too slow, or using a current setting that is too high.

If the manufacturer of your plasma cutter provides mechanized cutting charts, then follow their recommendations for current setting, pierce height, cut height, pierce delay, cutting speed, and designated consumables for your particular cutting process.

David

[robertspark]

are you cutting in the right direction....

CCW for inside cuts,

CW for outside cuts.

greater bevel on the LHS of the forward cut direction

https://www.google.com/url?sa=t&source= ... NyPrgXm0HC

[adbuch]

CW for inside cuts,

CCW for outside cuts.

This is incorrect. You've got it backwards. Hypertherm and most all other machines use clockwise swirl rings - CCW for inside cuts and CW for outside cuts will give the best results. The squarest edge will be to the right side when traveling forward while cutting. The side with the most bevel will be to the left side when traveling forward while cutting.

David

[robertspark]

CW for inside cuts,

CCW for outside cuts.

This is incorrect. You've got it backwards. Hypertherm and most all other machines use clockwise swirl rings - CCW for inside cuts and CW for outside cuts will give the best results. The squarest edge will be to the right side when traveling forward while cutting. The side with the most bevel will be to the left side when traveling forward while cutting.

David

can't will them all, whatever it says in the pdf link I provided rtfm always served me well

[cutnweld]

Yup. Pdf agrees with adbuch

[shizyo]

I use Hypertherm 45. I always set up CCW for inside cuts and CW for outside cuts. What PSI at your compressors, I have 120PSI at my compressor, is it too much and it will cause issue with the air flow inside the torch?

[djreiswig]

What is the pressure at the rear of the cutter after any filters and line loss from hoses. You should have at least 90psi. The hypertherm has an internal pressure regulator that automatically sets the pressure depending on the torch lead length.

[adbuch]

I use Hypertherm 45. I always set up CCW for inside cuts and CW for outside cuts. What PSI at your compressors, I have 120PSI at my compressor, is it too much and it will cause issue with the air flow inside the torch?

Do you have a 45 or 45xp? The Hypertherm 45xp book settings for 18 ga. SS using FineCut consumables are pierce height 0.080", cut height 0.020", 325 ipm cut speed, and set cutter to 45 amps. These are the settings I would start with If I were cutting 18 ga. SS with my 45xp using FineCuts.

For 45xp non-FineCut the thinnest SS listed in the cut chart is 16 ga. The settings for this are pierce height 0.150", cut height 0.060", 320 ipm cut speed, and set cutter to 45 amps.

If you are using the 45 (not the 45xp) and have a manual with cut charts for mechanized cutting, then I would recommend starting with those settings and using the specific consumables listed at the top of the cut chart. I would also recommend that you only use OEM Hypertherm consumables, and steer clear of the aftermarket imported stuff.

My compressor cycles between 125 and 175 psi. I have a dedicated regulator and pressure gauge at the entrance to both of my cutters (45xp and 85) so the air pressure to the plasma cutter air inlet stays right around 100 psi with air flowing thru the torch.

David

[robertspark]

powermax 45 (non xp) duramax torch cut charts
https://www.hypertherm.com/Download?fil ... &zip=False

powermax 45 (non xp) original torch cut charts

https://www.google.com/url?sa=t&source= ... ccqZuzskNc



powermax 45xp cut charts (rev 4 Oct 2020)

https://www.hypertherm.com/Download?fil ... &zip=False

[adbuch]

powermax 45 (non xp) duramax torch cut charts
https://www.hypertherm.com/Download?fil ... &zip=False

powermax 45 (non xp) original torch cut charts

https://www.google.com/url?sa=t&source= ... ccqZuzskNc



powermax 45xp cut charts (rev 4 Oct 2020)

https://www.hypertherm.com/Download?fil ... &zip=False

Great information to have! Thanks for posting.
David

[shizyo]

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Thanks for the pics. They are quite useful for me. I can see that you are using quite a larger air hose than mine. May I please ask the diameter of the air hose and its air fittings? Is it 3.8" ID and 1/4 NPT?

[adbuch]

Yes - the flexible air hose is 3/8" ID x 1/4" NPT fittings. This is only from the refrigerated drier to the the plasma cutter. The main air line from the compressor running around the main shop is 3/4" rigid copper. The feed from the main shop to the machine shop where the Plasmacam table is located is a combination of 3/4" copper and 1/2" pvc.
David

[djreiswig]

Pvc shouldn't be use for compressed air. The oils will cause it to deteriorate and it can explode sending shrapnel everywhere.

[adbuch]

Pvc shouldn't be use for compressed air. The oils will cause it to deteriorate and it can explode sending shrapnel everywhere.

I have about 100 ft. of 1/2" schedule 40 pvc (rated at 600 psi) in the machine shop. This is run inside the walls between the wall studs - so not exposed to UV light. In addition this 100 ft. run is proceeded by about 150 ft. of 3/4" rigid copper pipe with both oil and moisture traps installed between these two runs. So compressor/copper/oil trap/moisture trap/pvc/refrigerated dryer/flexible 3/8" ID air hose/air regulator/plasma cutter. The machine shop was built in 2003 and the pvc installed at that time. I have never had any problems with deterioration from oil, uv, etc. and this has held up fine.
David

[djreiswig]

Until it doesn't...

[adbuch]

Until it doesn't...

No Oil + No UV = No Deteriation.