CARBIDE TIPPED REAMERS
TECHNICAL INFORMATION
COST EFFECTIVE REAMER SELECTION - CARBIDE TIPPED VS. HSS AND COBALT
1
FIND THE CLASS FOR MATERIAL BEING REAMED - SEE TOOL SELECTION CHART
2
DETERMINE MATERIAL CONDITION AND HARDNESS
3
DETERMINE TOTAL NUMBER OF HOLES TO BE REAMED, THEN LOCATE MOST COST EFFECTIVE REAMER ON MATERIAL CONDITION/HARDNESS LINE
CHIP
CLASS
MATERIAL
CLASS
MATERIAL
CONDITION/HARDNESS
TOTAL NUMBER OF HOLES TO BE REAMED
1 5 10 20 40 80 160 320 640
20 NON-FERROUS LONG CHIPS SOFT - UNDER 10% SILICON HSS HSS HSS HSS CT CT CT CT CT
ABRASIVE - OVER 10% SILICON HSS Cobalt CT CT CT CT CT CT CT
40 NON-FERROUS SHORT CHIPS SOFT - FREE MACHINING HSS HSS HSS HSS CT CT CT CT CT
HARD - HIGH TENSILE HSS Cobalt Cobalt CT CT CT CT CT CT
60 CAST IRONS SOFT - 120 TO 220 Bhn HSS HSS HSS CT CT CT CT CT CT
MEDIUM - 220 TO 300 Bhn HSS Cobalt Cobalt CT CT CT CT CT CT
HARD - OVER 300 Bhn HSS Cobalt CT CT CT CT CT CT CT
80 LOW STRENGTH STEELS SOFT - 80 TO 175 Bhn HSS HSS HSS CT CT CT CT CT CT
MEDIUM - 176 TO 275 Bhn HSS Cobalt CT CT CT CT CT CT CT
HARD - OVER 275 Bhn Cobalt Cobalt CT CT CT CT CT CT CT
100 MEDIUM STRENGTH STEELS SOFT - 150 TO 275 Bhn HSS HSS HSS CT CT CT CT CT CT
MEDIUM - 276 TO 425 Bhn HSS Cobalt CT CT CT CT CT CT CT
HARD - OVER 45 Rc Cobalt CT CT CT CT CT CT CT CT
120 HIGH STRENGTH STEELS SOFT - 135 TO 275 Bhn HSS HSS CT CT CT CT CT CT CT
MEDIUM - 276 TO 425 Bhn Cobalt Cobalt CT CT CT CT CT CT CT
HARD - OVER 45 Rc Cobalt CT CT CT CT CT CT CT CT
140 HIGH TEMPERATURE ALLOYS ALL CONDITIONS CT CT CT CT CT CT CT CT CT
CT=Carbide Tipped HSS= High Speed Steel
REAMER BASICS
  • 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 45º 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
DECREASE YOUR MACHINING COST PER HOLE REAMED WITH CARBIDE TIPPED REAMERS
Why is total cost per hole reamed far lower with carbide tipped reamers despite its higher initial cost?
Because of:
  • Higher feeds & speeds due to heat resistant cutting edge - reduces machine cycle time per part
  • Consistent quality - maintains hole size and surface finish far longer
  • Longer tool life - reduces down time for tool changes

FREE TECHNICAL REAMING GUIDE AVAILABLE
Want more technical information? Request a free copy of "HANNIBAL'S Guide to Cost Effective Reaming."
it is continously updated to include the latest reamer technical developments, including:
Reamer Stock Removal Chart Developing Optimum Feeds & Speeds Titanium Coatings Flute Geometry Avoiding Reaming Problems Runout Concerns Reamer Nomenclature & Definitions

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 follows:
    Tool Diameter Guaranteed
    Minimum Expansion
    5/16" - 15/32" .006"
    1/2" - 31/32" .010"
    1" - 1 1/" .013"
    1 9/16" - 2 1/" .015"
     
REAMER TOLERANCES
  • Tool diameter tolerance:
        General purpose & Coolant fed
            Thru 1 1/2" tool diameter: plus .0003", minus .0000"
            Over 1 1/2" tool diameter: plus .0004", minus .0000"
        Material specific (NAS)
            Thru 1/2" tool diameter: plus .0002", minus .0000"
            Over 1/2" tool diameter thru 3/4": plus .0003", minus .0000"
            Over 3/4" tool diameter: plus .0004", minus .0000"
  • Shank diameter tolerance:
        General purpose
            minus .0005", minus.0015"
        Material specific (NAS) & Coolant fed
            Thru 23/32" tool diameter: plus .0000", minus .0010"
            Over 23/32" tool diameter: plus .0000", minus .0015"
  • Closer tool diameter tolerance pricing per tool:
    Standard Tolerance Modified to Closer Tolerance
    .0003" .0002" .0001"
    .0004 $ 1.00 $ 3.00 $ 5.00
    .0003 - $ 1.00 $ 3.00
    .0002 - - $ 3.00
     
REAMER PROBLEM SOLVING GUIDE - CARBIDE TIPPED
REAMING PROBLEMS POSSIBLE CAUSES POSSIBLE SOLUTIONS
1. POOR FINISH Unequal chamfers Regrind reamer with equal chamfer height
Incorrect margins Regrind reamer with narrower margins for reaming higher tensile materials
Excessive spindle runout Use bushing - .0002"/.0003" over reamer diameter
Chatter Increase speed and reduce feed rate
Use power feed unless material is hard
Use spiral fluted reamer
Grind secondary lead angle immediately behind 45º chamfer
Insufficient cutting action Specify reamer with positive radial rake to reduce cutting preasure - may
produce slightly larger diameter holes
2. OVERSIZED HOLES
TAPERED HOLES
BELL MOUTH HOLES
Misalignment Check fixturing & setup for possible causes; use floating holder if necessary
Consider using precision bushings or piloted reamers
Incorrect feed and/or speed Verify feeds & speeds
3. EXCESSIVE TOOL WEAR Improper stock removal Change pre-ream hole size to leave 2 to 3% of tool diameter
Excessive reaming pressure Decrease feed rate
See solution for "improper stock removal" in #3
Misalignment See solution for "misalignment" in #2
4. CROOKED HOLES Drill walking or incorrect sharpening Correct drilling operation - reamer will follow drilled hole
Increase 90º included chamfer angle to 120º - 180º
5. TOOL BREAKAGE Excessive reaming pressure See solution for "excessive reaming pressure" in #3
Misalignment See solution for "misalignment" in #2