Reamer with radial relief

A finish reamer adapted to finish ream a hard material, said reamer comprising:

• a member having a body section, said body section having a plurality of flutes, said flutes defining a plurality of cutting blades, each cutting blade having an axially extending radial relief formed therein for dissipating heat during reamer operation, said relief extending along a portion only of said cutting blade, each of said cutting blades including a cutting edge and a land, said radial relief extending transversely across the entire width of said land, said radial relief including smoothly curved forward and rearward ends, said cutting blades each having a rake angle of approximately 2 degrees, each of said lands including a narrow margin having an edge in common with said cutting edge and a heel, said heel being orientated at a relief angle to said margin, the width of said margin being within the range of 27.5 percent to 40 percent of the overall width of said land, and said reamer including a pilot section, said pilot section including a cylindrical portion and a fluted tapered portion.

A finish reamer for finishing a bore, said reamer comprising:

• a body section having a back tapered portion and having formed therein a plurality of spiral flutes, said flutes defining a plurality of cutting blades each having a rake face, a cutting edge, and a land, said land including a radial relief extending along the land a distance greater than the width of said land and terminating within the back tapered portion of the body section, said relief opening transversely through the rake face of said blade, each of said cutting blades including a pilot and surface finish portion rearwardly of each of said radial reliefs.

A finish reamer for finishing a bore, said reamer comprising:

• a back tapered body section having formed therein a plurality of spiral flutes, said flutes defining a plurality of cutting blades each having a rake face, a cutting edge, and a land, said land including a radial relief extending along the land a distance greater than the width of said land, said relief opening transversely through the rake face of said blade and said radial relief including smoothly rounded leading and trailing edges and a generally flat central section, said flat section being below the land a predetermined depth, each of said cutting blades including a pilot and surface finish portion rearwardly of each of said radial reliefs.