Abstract: A cylindrical, cup-shaped, porous, sintered powdered metal filter is sealed in a tubular thermoplastic fitting (e.g., the needle-retaining hub of a hypodermic needle or an adaptor or a connector in the line of an intravenous infusion set) by force-fitting the open end of the filter within an annular bead on the interior wall of the tubular fitting and induction heating the filter so that the thermoplastic bead will flow into the pores of the filter to form a continuous ring seal between the filter and the interior wall of the fitting.

Abstract: An improved filter for medical infusion and injection equipment is manufactured by compacting stainless steel powder particles of an irregular or dendritic shape, in the substantial absence of a binder, to form a porous, self-supporting green article, and thereafter sintering the green article. The resulting filter is porous with the pores communicating with one another to form a network of tortuous or winding paths having lateral, oblique and vertical segments which function to trap contaminating particles of a solution passed therethrough. The porous filter is sealed in a tubular fitting by force-fitting the filter into the internal peripheral wall of an annular plastic bead in the fitting and heating the filter to cause the plastic bead to soften or melt and flow into the pores of the filter along a continuous peripheral ring.