inches between each hole and a material thickness of approximately 0 046 inches outwardly of each of the extreme holes for a module of corresponding length for use with a conventional two knife block thirty two spigot receiving holes would be needed at 0 156 inch centers thus giving for a spigot receiving hole diameter of say 0 125 inches a land between adjacent holes of approximately 0 031 inches and a material thickness at the ends of the module of only 0 015 inches as can be appreciated by using four knife blocks so it is possible to provide a knife bar arrangement appropriate to the production of a 5 64 39 s gauge fabric whilst still being able to use knife blocks having spigots of substantial cross section and thus strength and a module having a substantial thickness of metal between adjacent spigot receiving holes and outwardly of the end such holes by adopting a module of approximately five inches in length so we are able to standardise on a module length for the majority of the range of conventional gauge sizes used in the tufting machine art in use in a tufting machine see now fig8 to 10 a plurality of modules as aforesaid is applied to a knife bar support 19 in end to end disposition thereon the stepped underside 31e of each module being seated on the knife bar support and the modules being secured in position by bolts 44 engaged with threaded holes 35 having regard to the fact that the material.