Reamer Basics: Types & Specifications

The reamer is used to finish machine a previously formed hole to an exact diameter with a smooth finish. It should not be used to significantly enlarge a hole (max. 5% – depending on material and hardness).

• Carbide tipped reamers are especially appropriate for close tolerance reaming. Because carbide is very highly resistant to wear, the reamer will produce accurate hole size and a smooth finish far longer than high speed steel or cobalt.
• The reamer is an end cutting tool, cutting only on the chamfer’s edge at the outside diameter of the preformed hole
• The standard 45° chamfer angle provides effective cutting action for most materials

Reamer Types

• General Purpose – Superior performance over high speed steel and cobalt; good in a wide variety of materials 
  
• Material Specific – Excellent in large production runs due to material specific carbide & tool geometry
• Coolant Fed – Exceptional performance and tool life using material specific reamer technology and coolant fed capabilities; maximizes feeds & speeds

Reamer Specifications

• Geometry and carbide grade appropriate for material being machined
• Carbide tips brazed to tough hardened alloy steel body, except expansion reamers which are not hardened
• Polished flutes for easy chip flow
• ASME/ANSI B94.2; NAS 897; USCTI • Precision ground cutting edges• “Taper Shank No.” refers to American Standard taper series (formerly Morse taper series) per ASME/ANSI B5.10
• Material specific reamer shanks are ground to next smallest shank diameter listed in NAS 897 if tool diameter is within .005” of shank diameter
  

Expansion reamers can be expanded for regrinding as shown in this chart.