To　better　understand　keyhole　plasma　arc　(PA)　and　help　improve　the　process,　the　authors　recently　observed　that　the　electron　flow　may　deviate　from　its　ionized　arc　plasma　which　is　electrically　neutral.　This　phenomenon　has　been　referred　to　as　the　arc　separability　which　provides　a　better　way　to　understand　the　arc　fundamentally.　Hence,　in　this　study　the　authors　designed　an　innovative　experimental　system　to　measure/record　the　heat　and　pressure　from　the　separated　arc　components-arc　plasma　and　electron　flow.　An　algorithm　was　proposed　to　calculate/derive　the　distribution　of　the　pressure　from　its　bulk　measurements　that　are　easy　to　obtain　accurately.　Experiments　were　conducted　to　study　the　effects　of　welding　parameters　on　the　heat　and　pressure　in　the　arc　components.　It　is　found　that　for　the　constrained　PA,　the　heat　applied　into　the　work-piece　through　the　arc　plasma　exceeds　that　from　the　electron　flow　and　this　dominance　increases　as　the　current　increases.　However,　for　the　heat　from　the　electron　flow,　the　constraint　on　the　arc　does　not　change　it　significantly　as　can　be　seen　from　the　comparison　with　that　in　free　gas　tungsten　arc　(GTA).　For　the　pressure　in　PA,　the　arc　plasma　plays　the　dominant　role　in　determining　its　amplitude,　while　the　electron　flow　only　primarily　contributes　to　the　distribution.