Bleed screws, plastic

For the function and application criteria of the GN 552 vent screws, see the functional description. MAX-MIN marking lines can easily be applied to the surfaces of the oil dipstick (see GN 109). The version with oil dipstick (form B) is only possible with code numbers 0, 1 and 2, namely: Size 31 - all threads Size 42 - only G 3/4 and G 1 Size 57 - only G 1 1/4 and G 1 1/2