compaction step the compact is sintered in a conventional sintering furnace using conventional sintering temperatures ranging on the order from about 800 u00b0 c to about 1350 u00b0 c for ferrous powder metals and ranging on the order from about 700 u00b0 c to about 900 u00b0 c for non ferrous materials sintering times typically range on the order from about ten minutes to about one hour the sintering process serves to bond of adjacent powder surfaces in the compact and thereby form an integrally sintered mass sintering furnace atmospheres may be performed in a reducing atmosphere an inert atmosphere or under vacuum the sintered product is a solid elongated sintered metal blank having a generally cylindrical cross section and characterized by generally uniform density and hardness from end to end as in the case of the pressed compact the sintered blank remains off round and has surface ridges again further shaping is required to produce a finished valve guide following the sintering step the longitudinal external surface of the generally cylindrical blank is formed to obtain a desired essentially round shape a desired diameter and a desired surface texture forming may be accomplished by for example but not limited to grinding turning milling broaching or passage through a die such forming process may include one or more of the above mentioned forming techniques for.