Calibres Marlco para roscas - Rosca inglesa Whitworth

These thread measuring parallels represent what is probably the simplest and most flexible method of checking the EFFECTIVE DIAMETER of external screw threads. They are manufactured to the highest degree of accuracy and to a specification certified by the National Physical Laboratory. Each pair covers a range of pitches irrespective of diameter or direction of thread.

These parallels are supplied as sets or individual pairs complete with plastic clips (for products ending in P)

Full range: 40 to 4.5 T.P.I..

Sets are presented in plush lined boxes.