{"id":3243,"date":"2026-08-20T05:44:01","date_gmt":"2026-08-19T21:44:01","guid":{"rendered":"https:\/\/www.weldmc.com\/news\/cnc-plasma-cutting-amperage-chart-by-material-thickness\/3243\/"},"modified":"2026-08-20T05:44:01","modified_gmt":"2026-08-19T21:44:01","slug":"cnc-plasma-cutting-amperage-chart-by-material-thickness","status":"publish","type":"post","link":"https:\/\/www.weldmc.com\/es\/noticias\/cnc-plasma-cutting-amperage-chart-by-material-thickness\/3243\/","title":{"rendered":"CNC Plasma Cutting Amperage Chart by Material Thickness"},"content":{"rendered":"

CNC plasma cutting amperage sets the ceiling for what a table can cleanly pierce, edge, and produce at production speed. Amperage alone does not guarantee a clean cut across mild steel, stainless steel, and aluminum; gas choice, torch height, nozzle size, and table acceleration all shape the result. In the machines I have commissioned, the most common amperage errors come from copying a vendor chart without checking whether the listed value applies to piercing, edge start, or fine-cut consumables. This guide gives practical amperage and thickness settings and shows where the published numbers need adjustment.<\/p>\n

Amperage Control of Cut Speed, Edge Quality, and Piercing Capability<\/h2>\n

Amperage on a CNC plasma system sets arc power density and the maximum material thickness a torch can handle in a given cut cycle. It works across two different cut modes. Edge start feeds the arc from the plate edge; piercing starts with the torch stationary over the surface. Edge start can handle thicker metal at a given amperage because the molten material flows out from the edge instead of being blown upward into the torch. I have watched shops reject a 30 mm steel blank on a 130 A machine because the part required a pierce start while the published chart only called out edge-start thickness.<\/p>\n

Inside the cut, amperage changes kerf width, bevel angle, heat-affected zone, and dross adhesion. A lower amperage at higher travel speed narrows kerf and reduces warping on sheets under 6 mm. Higher amperage moves more metal per minute but leaves a wider cut and more heat input to fight. The torch height control and the table’s corner acceleration have just as much effect on cut squareness as the amperage number itself.<\/p>\n

CNC Plasma Cutting Amperage Chart by Material Thickness<\/h2>\n

The ranges below are production starting points for conventional air, oxygen, or nitrogen plasma systems. They assume square-cut nozzles in good condition, clean dry gas, correct torch height, and a part profile without tightly nested corners.<\/p>\n\n\n\n\n\n\n\n\n\n
Metal type<\/th>\nAmperage range<\/th>\nClean production cut<\/th>\nMaximum production pierce<\/th>\nNotes<\/th>\n<\/tr>\n<\/thead>\n
Mild steel<\/td>\n40-60 A<\/td>\n3-8 mm<\/td>\n6 mm<\/td>\nAir, oxygen, or nitrogen; low dross at correct speed<\/td>\n<\/tr>\n
Mild steel<\/td>\n80-120 A<\/td>\n8-20 mm<\/td>\n12 mm<\/td>\nOxygen or air; bevel becomes visible above 16 mm<\/td>\n<\/tr>\n
Mild steel<\/td>\n130-200 A<\/td>\n20-50 mm<\/td>\n25 mm<\/td>\nRequires high-definition equipment for square edges<\/td>\n<\/tr>\n
Stainless steel<\/td>\n45-80 A<\/td>\n2-10 mm<\/td>\n8 mm<\/td>\nNitrogen or air; heat tint remains on cut face<\/td>\n<\/tr>\n
Aluminum<\/td>\n45-100 A<\/td>\n2-16 mm<\/td>\n10 mm<\/td>\nAir or nitrogen; roughness increases above 12 mm<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Stainless steel above 10 mm follows the 80-200 A range, but at roughly 15-20 percent lower travel speed than mild steel of the same thickness. Aluminum above 16 mm usually needs 100-200 A; some shops move to high-definition plasma or waterjet when edge squareness must stay tighter than 2 degrees.<\/p>\n

\"Posicionador<\/p>\n

Production Adjustments to Published Amperage Charts<\/h2>\n

Published amperage charts are true at a static moment in a test cut. Production parts with holes, slots, and sharp internal corners force the table to decelerate. The torch dwells longer in the corner and can burn out the top edge even though the amperage setting has not changed. We compensate with a corner speed override or a separate lead-in rule before relying on the chart across a dense nest.<\/p>\n

\n

Edge squareness and dross left by cutting carry directly into weld fit-up. <C\u00f3mo mejorar la calidad de la soldadura de tuber\u00edas mediante un posicionador de soldadura de alta precisi\u00f3n<\/a>> covers why stable edge preparation and positioning matter once plasma-cut components move into welding cells.<\/p>\n<\/blockquote>\n

Pierce delay, nozzle condition, and air moisture are three variables that move the real result away from the chart. A 100 A cut on 16 mm mild steel can look worse than a 60 A cut on 10 mm if the nozzle has eroded or the compressor is feeding wet air. If the chart calls for 100 A and the edge shows heavy top rounding, inspect the consumable stack before assuming the table is underpowered.<\/p>\n

Amperage Selection for Mild Steel, Stainless Steel, and Aluminum<\/h2>\n

Mild steel tolerates the widest amperage window. Oxygen plasma on 12-20 mm plate produces a square face and light oxide; air is cheaper but leaves a slightly nitrided surface that can affect later coating or weld prep. Stainless steel resists the arc differently. The conservative rule is to hold the cut kerf target and reduce travel speed rather than raise amperage. On 10 mm stainless, I prefer 80 A with nitrogen over pushing 100 A with air because the lower heat input gives a cleaner edge and less heat tint.<\/p>\n

Aluminum has high thermal conductivity and a low melting point, so it cuts with a wider rough zone than steel at the same power. An 80 A arc that cleanly severs 12 mm mild steel may leave heavy burr on 10 mm aluminum with air. For aluminum above 10 mm, nitrogen or an argon-hydrogen mix gives a cleaner face if the edge finish drives downstream work, but gas cost rises.<\/p>\n

In mixed-metal production, the largest amperage machine is not automatically the best cutting tool. A 200 A plasma table can cut 3 mm stainless, but it also uses larger consumables, a wider kerf, and more heat. If most work is under 12 mm, a 100 A or 120 A power supply is usually more stable and less costly to run.<\/p>\n

If your cutting plan mixes thin stainless and 20 mm mild steel, confirm the torch, gas console, and CAM rules are matched before quoting capacity. Send your material mix and edge requirement to jay@weldc.com to receive a power supply and consumable recommendation.<\/p>\n

\"Posicionador<\/p>\n

Cutting Parameter Confirmation Before Purchase<\/h2>\n

Amperage charts get quoted as if a 100 A table can produce every thickness in the brochure at full speed. The real question is whether the table can handle your pierce schedule, your material mix, and the edge finish your downstream welding requires. At WUXI ABK, we configure CNC plasma cutting packages<\/a> around the actual cut chart rather than just the power supply rating.<\/p>\n

Send your material range, maximum production thickness, and required edge quality to jay@weldc.com or call +86-13815101750 \/ +86-510-83555592. We can match power supply, torch height control, gas selection, and table dynamics to the parts you actually cut.<\/p>\n

\"Posicionador<\/p>\n

Common Questions About CNC Plasma Cutting Amperage<\/h2>\n

Can a 60 A plasma cutter cut 20 mm mild steel?<\/h3>\n

No. A 60 A plasma cutter can sever 20 mm mild steel from an edge start in a straight line, but it will not production pierce that thickness reliably. Piercing 20 mm requires enough arc energy to blow molten metal out before the nozzle is damaged, and 60 A is below the practical piercing limit for most conventional systems. If the part has holes or internal profiles, plan on 100-130 A and a proper pierce delay. For edge-start-only long cuts, 60 A can work, but travel speed will be slow and the bevel angle will be visible.<\/p>\n

Why does the same amperage leave dross on stainless steel but not mild steel?<\/h3>\n

Many shops blame amperage first when stainless dross is the problem. Stainless steel has lower thermal conductivity than mild steel, so heat builds up at the cut face and molten oxide resolidifies along the bottom edge more readily. Amperage can worsen dross if too high, but the first checks are travel speed, gas quality, and nozzle condition. Nitrogen at the correct flow usually gives a cleaner edge than air, and reducing speed slightly works better than reducing amperage alone. If dross is hard and fused, raise speed in small steps before changing power.<\/p>\n

Is higher amperage always faster on a CNC plasma table?<\/h3>\n

It depends on the part geometry and table acceleration. Higher amperage removes more metal per unit time on a straight cut, but it also widens the kerf and injects more heat into thin sections. A 200 A setting on 6 mm sheet may create distortion, a rough wide cut, and higher consumable wear with no speed gain over 80-100 A because the table cannot corner fast enough. Use high amperage only when material thickness and straight-line cutting length justify it. For dense nests with many holes under 10 mm, stay in the lower amperage band.<\/p>\n

How do I know whether to use a 100 A or 200 A system for a new contract?<\/h3>\n

Start with the heaviest plate that must be pierced, not the heaviest plate cut from an edge. I have seen buyers size a plasma system around a 25 mm edge-start brochure value, then fail when the same contract calls for 25 mm pierce starts. Determine whether parts have internal holes, slots, or thin webs; those require pierce capability and controlled corner speed. Then match gas type and duty cycle. Share your maximum piercing thickness, plate grades, and required edge squareness with WUXI ABK at jay@weldc.com or +86-510-83555592, and we will confirm the appropriate amperage and consumable configuration.<\/p>\n

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CNC plasma cutting amperage sets the ceiling for what a table can cleanly pierce, edge, and produce at production speed. Amperage alone does not guarantee a clean cut across mild steel, stainless steel, and aluminum; gas choice, torch height, nozzle size, and table acceleration all shape the result. In the machines I have commissioned, the […]<\/p>","protected":false},"author":1,"featured_media":2387,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","_seopress_robots_follow":"","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"","_seopress_social_fb_title":"","_seopress_social_fb_desc":"","_seopress_social_fb_img":"","_seopress_social_fb_img_attachment_id":0,"_seopress_social_fb_img_width":0,"_seopress_social_fb_img_height":0,"_seopress_social_twitter_title":"","_seopress_social_twitter_desc":"","_seopress_social_twitter_img":"","_seopress_social_twitter_img_attachment_id":0,"_seopress_social_twitter_img_width":0,"_seopress_social_twitter_img_height":0,"_seopress_redirections_value":"","_seopress_redirections_enabled":"","_seopress_redirections_enabled_regex":"","_seopress_redirections_logged_status":"","_seopress_redirections_param":"","_seopress_redirections_type":0,"_seopress_analysis_target_kw":"","_seopress_news_disabled":"","_seopress_video_disabled":"","_seopress_video":[],"_seopress_pro_schemas_manual":[],"_seopress_pro_rich_snippets_disable_all":"","_seopress_pro_rich_snippets_disable":[],"_seopress_pro_schemas":[],"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3243","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"blocksy_meta":[],"acf":[],"_links":{"self":[{"href":"https:\/\/www.weldmc.com\/es\/wp-json\/wp\/v2\/posts\/3243","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.weldmc.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.weldmc.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.weldmc.com\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.weldmc.com\/es\/wp-json\/wp\/v2\/comments?post=3243"}],"version-history":[{"count":0,"href":"https:\/\/www.weldmc.com\/es\/wp-json\/wp\/v2\/posts\/3243\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.weldmc.com\/es\/wp-json\/wp\/v2\/media\/2387"}],"wp:attachment":[{"href":"https:\/\/www.weldmc.com\/es\/wp-json\/wp\/v2\/media?parent=3243"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.weldmc.com\/es\/wp-json\/wp\/v2\/categories?post=3243"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.weldmc.com\/es\/wp-json\/wp\/v2\/tags?post=3243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}