A gas spring for forming equipment, comprising: a casing (12; 312; 612) including an axially extending side wall, an open end, a transversely extending closed end wall axially spaced from the open end, a pressure chamber (217; 317; 617) established in part by the side and end walls to receive a gas under pressure; a piston rod (216; 316; 616) received at least in part in the casing (12; 312; 612) for reciprocation between extended and retracted positions; a piston rod housing (244; 344; 644) disposed between the piston rod (216; 316; 616) and the casing (12; 312; 612) and including an interior end (268; 368; 668), and an exterior end axially spaced from the interior end (268; 368; 668), and characterized by an overtravel pressure relief passage (266; 366; 666) extending generally axially into and radially between radially inner and outer peripheries of the piston rod housing (244; 344; 644) and intersecting the exterior end, wherein the overtravel pressure relief passage is a blind bore (266; 366; 666) having a bottom wall (269; 372; 672) at the interior end (268; 368; 668) of the piston rod housing (244; 344; 644); and an overtravel pressure relief member (260; 360; 660) carried in the overtravel pressure relief passage (266; 366; 666) and having an exterior end (264; 361; 661) that projects axially beyond the piston rod housing (244; 344; 644), wherein the overtravel pressure relief member (260; 360; 660) includes a hollow rod or a solid pin (360; 660) carried in the blind bore (266; 366; 666) of the piston rod housing (344; 644) and having an exterior end (264; 361; 661) for contact with a driving member and an interior end (262; 362; 662) for rupturing the bottom wall (269; 372; 672) of the blind bore (266; 366; 666) in the piston rod housing (244; 344; 644) when the driving member drives the hollow rod or the solid pin (360; 660) further into the piston rod housing (244; 344; 644). a casing (12; 312; 612) including an axially extending side wall, an open end, a transversely extending closed end wall axially spaced from the open end, a pressure chamber (217; 317; 617) established in part by the side and end walls to receive a gas under pressure; a piston rod (216; 316; 616) received at least in part in the casing (12; 312; 612) for reciprocation between extended and retracted positions; a piston rod housing (244; 344; 644) disposed between the piston rod (216; 316; 616) and the casing (12; 312; 612) and including an interior end (268; 368; 668), and an exterior end axially spaced from the interior end (268; 368; 668), and characterized by an overtravel pressure relief passage (266; 366; 666) extending generally axially into and radially between radially inner and outer peripheries of the piston rod housing (244; 344; 644) and intersecting the exterior end, wherein the overtravel pressure relief passage is a blind bore (266; 366; 666) having a bottom wall (269; 372; 672) at the interior end (268; 368; 668) of the piston rod housing (244; 344; 644); and an interior end (268; 368; 668), and an exterior end axially spaced from the interior end (268; 368; 668), and characterized by an overtravel pressure relief passage (266; 366; 666) extending generally axially into and radially between radially inner and outer peripheries of the piston rod housing (244; 344; 644) and intersecting the exterior end, wherein the overtravel pressure relief passage is a blind bore (266; 366; 666) having a bottom wall (269; 372; 672) at the interior end (268; 368; 668) of the piston rod housing (244; 344; 644); and an overtravel pressure relief member (260; 360; 660) carried in the overtravel pressure relief passage (266; 366; 666) and having an exterior end (264; 361; 661) that projects axially beyond the piston rod housing (244; 344; 644), wherein the overtravel pressure relief member (260; 360; 660) includes a hollow rod or a solid pin (360; 660) carried in the blind bore (266; 366; 666) of the piston rod housing (344; 644) and having an exterior end (264; 361; 661) for contact with a driving member and an interior end (262; 362; 662) for rupturing the bottom wall (269; 372; 672) of the blind bore (266; 366; 666) in the piston rod housing (244; 344; 644) when the driving member drives the hollow rod or the solid pin (360; 660) further into the piston rod housing (244; 344; 644).