A power transfer assembly (100;200;300;500;600;700;750) for supplying electrical power to an electrode of a contact-start plasma arc torch, the power transfer assembly comprising: a static element (106;206;506;702;762) of conductive material having: a static element spring-engaging bearing surface, a first mating structure defined by first mating structure sidewalls that are parallel axis (130;712), to an assembly and a static element spring end retainer (134;212;514;618;722); a movable element (108;202;502;704;766) of conductive material having; a movable element spring-engaging bearing surface, a second mating structure defined by second mating structure sidewalls that are axis (130;712), parallel to the assembly said second mating structure being configured to translatably engage said first mating structure along the assembly axis (130;712) when rotationally aligned therewith, but configured so as to be blocked from rotating with respect to said first mating structure when translatably engaged therewith, a movable element spring end retainer (148;212;518;616;722); and a compression and torsion spring (110;204;504;614;706;768) having: a spring first end (152;214;516;612;720) configured to engage said static element spring end retainer (134;212;514;618;722) so as to block rotation between said spring first end (152;214;516;612;720) and said static element (106;206;506;702;762) about the assembly axis (130;712), and a spring second end (154;214;520;610;720) configured to engage said movable element spring end retainer (148;212;518;616;722) so as to block rotation between said spring second end (154;214;520;610;720) and said movable element (108;202;502;704;766) about the assembly axis (130;712), said compression and torsion spring (110;204;504;614;706) being configured to engage said static element (106;206;506;702;762) and said movable element (108;202;502;704;766) in such a manner as to be torsioned when said mating structures are aligned with and translatably engaged with each other, thereby torsionally forcing said first mating structure sidewalls into contact with said second mating structure sidewalls along at least one line of contact. a static element (106;206;506;702;762) of conductive material having: a static element spring-engaging bearing surface, a first mating structure defined by first mating structure sidewalls that are parallel axis (130;712), to an assembly and a static element spring end retainer (134;212;514;618;722); a movable element (108;202;502;704;766) a static element spring-engaging bearing surface, a first mating structure defined by first mating structure sidewalls that are parallel axis (130;712), to an assembly and a static element spring end retainer (134;212;514;618;722); a movable element (108;202;502;704;766) of conductive material having; a movable element spring-engaging bearing surface, a second mating structure defined by second mating structure sidewalls that are axis (130;712), parallel to the assembly said second mating structure being configured to translatably engage said first mating structure along the assembly axis (130;712) when rotationally aligned therewith, but configured so as to be blocked from rotating with respect to said first mating structure when translatably engaged therewith, a movable element spring end retainer (148;212;518;616;722); and a compression and torsion spring (110;204;504;614;706;768) having: a spring first end (152;214;516;612;720) configured to engage said static element spring end retainer (134;212;514;618;722) so as to block rotation between said spring first end (152;214;516;612;720) and said static element (106;206;506;702;762) about the assembly axis (130;712), and a spring second end (154;214;520;610;720) configured to engage said movable element spring end retainer (148;212;518;616;722) so as to block rotation between said spring second end (154;214;520;610;720) and said movable element (108;202;502;704;766) about the assembly axis (130;712), said compression and torsion spring (110;204;504;614;706) being configured to engage said static element (106;206;506;702;762) and said movable element (108;202;502;704;766) in such a manner as to be torsioned when said mating structures are aligned with and translatably engaged with each other, thereby torsionally forcing said first mating structure sidewalls into contact with said second mating structure sidewalls along at least one line of contact. a spring first end (152;214;516;612;720) configured to engage said static element spring end retainer (134;212;514;618;722) so as to block rotation between said spring first end (152;214;516;612;720) and said static element (106;206;506;702;762) about the assembly axis (130;712), and a spring second end (154;214;520;610;720) configured to engage said movable element spring end retainer (148;212;518;616;722) so as to block rotation between said spring second end (154;214;520;610;720) and said movable element (108;202;502;704;766) about the assembly axis (130;712), said compression and torsion spring (110;204;504;614;706) being configured to engage said static element (106;206;506;702;762) and said movable element (108;202;502;704;766) in such a manner as to be torsioned when said mating structures are aligned with and translatably engaged with each other, thereby torsionally forcing said first mating structure sidewalls into contact with said second mating structure sidewalls along at least one line of contact.