A mold for casting a workpiece, comprising: a casting shell comprising an interior shell surface; a casting core (14,16) located within the shell, and comprising a sidewall (30,40) extending between a first core surface (32,42) and a second core surface (34,44); and a casting pin (18,20;130) supporting the core (14;16) within the shell, and comprising an intermediate segment (98,100;134) connected between a first support segment (86,88,90;138) and a second support segment (92,94,96;140), wherein the intermediate segment (98,100;134) contacts the sidewall (30,40), the first support segment (86,88,90;138) extends from the first core surface (32,42) to a first side of the interior shell surface, and the second support segment (92,94,96;140) extends from the second core surface (34,44) to a second side of the interior shell surface that is opposite the first side, wherein the casting pin (18;130) further comprises a first notch (104;132) extending into the casting pin (18;130) between the first and the second support segments (86,92;154,156), and a first region of the core adjacent to the sidewall extends into the first notch (104;132); characterised in that: the core further comprises an aperture (36; 136) extending between the first and the second core surfaces (30,32), and wherein the aperture (36; 136) comprises the sidewall; and in that the casting pin (18,20;130) and the aperture (36;136) are configured such that the first support segment (86,88,90;138) may be passed through the aperture (36;136) until the intermediate segment (98,100;134) is aligned with the casting core (14,16), whereupon the first support segment (86,88,90;138) and the second support segment (92,94,96;140) may be twisted such that first support segment (86,88,90;138) partially overlaps the first core surface and the second support segment (92,94,96;140) partially overlaps the second core surface. a casting shell comprising an interior shell surface; a casting core (14,16) located within the shell, and comprising a sidewall (30,40) extending between a first core surface (32,42) and a second core surface (34,44); and a casting pin (18,20;130) supporting the core (14;16) within the shell, and comprising an intermediate segment (98,100;134) connected between a first support segment (86,88,90;138) and a second support segment (92,94,96;140), wherein the intermediate segment (98,100;134) contacts the sidewall (30,40), the first support segment (86,88,90;138) extends from the first core surface (32,42) to a first side of the interior shell surface, and the second support segment (92,94,96;140) extends from the second core surface (34,44) to a second side of the interior shell surface that is opposite the first side, wherein the casting pin (18;130) further comprises a first notch (104;132) extending into the casting pin (18;130) between the first and the second support segments (86,92;154,156), and a first region of the core adjacent to the sidewall extends into the first notch (104;132); characterised in that: the core further comprises an aperture (36; 136) extending between the first and the second core surfaces (30,32), and wherein the aperture (36; 136) comprises the sidewall; and in that the casting pin (18,20;130) and the aperture (36;136) are configured such that the first support segment (86,88,90;138) may be passed through the aperture (36;136) until the intermediate segment (98,100;134) is aligned with the casting core (14,16), whereupon the first support segment (86,88,90;138) and the second support segment (92,94,96;140) may be twisted such that first support segment (86,88,90;138) partially overlaps the first core surface and the second support segment (92,94,96;140) partially overlaps the second core surface.