which passes through a steel stud or construction member as used for supporting wallboard in the drawings a protector plate unit is generally indicated by the reference 10 the unit 10 is shown in fig1 in an unformed state the protector plate unit 10 is formed in one piece from metal sheet and is shown in fig1 as stamped from sheet steel the unit 10 has a central mounting web 12 which is generally rectangular the first and second protector plates 14 16 extend from either side of the web 12 and again are generally rectangular at the centre of the mounting web 12 an aperture 18 is punched having the profile as shown around the aperture 18 as indicated by the dotted line 20 there is an annular portion 22 for forming a collar as detailed below extending radially inwardly from its annular portion are tabs 24 whose function is again detailed below in production the blank of fig1 is formed into the protector plate unit by folding the first and second protector plates 14 16 along lines 26 the annular portion 23 is punched to form a collar 28 having the profile as shown in fig3 and 4 thus the material of the collar extends in section through approximately 180 u00b0 also the tabs 24 are bent to form the profile shown in fig2 and 3 thus the tabs 24 have their roots extending parallel to the plane of the web 12 and spaced therefrom the tabs then extend through a right angle and outwardly and perpendicular to the web 12 the use of the protector plate unit 10 will.