1/8 BSP: 9.5 mm ≈ 0.37" = DN6. 1 BSP: 32 mm ≈ 1.26 in = DN25. 1-1/4 BSP: 40 mm ≈ 1 in = DN32. 1-1/2 BSP: 50 mm ≈ 1 in = DN40. Material Brass.
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