ROUGH BORING HEADS
ROUGH BORING GUIDELINES
Insert Selection & Stock Allowance BIG KAISER indexable inserts outlined in the Insert Selection & Cutting Data tables have been selected to give optimum results. Grades and geometry do not have to be specified at time of order. Insert radius is based on 2 major factors: 1. Length/Diameter ratio of tool 2. Depth of cut or material allowance • Select the largest nose radius available for cutting edge strength & higher feeds • Use small nose radius for light depth of cut & extreme L/D ratio Feed 1. Feed: Based on effective number of inserts, depending on roughing method • Balanced Cutting: 2 effective inserts • Stepped Cutting: 1 effective insert • Full Profile Cutting: 1 effective insert 2. Under normal rough boring operations, the effective feed rate is about 50% of nose radius
Insert Radius .008 (0) .016 (1) .031 (2) .047 (3)
Minimum D.O.C.
Maximum D.O.C.
L/D Ratio
.010 .020 .040 .060
.060 .120 .200 .325
>6:1 ≤5:1 ≤4:1 ≤4:1
• D.O.C. is stock allowance/side (radius)
Feed/IPR
Nose Radius .008 (0) .016 (1) .031 (2) .047 (3)
Balanced Cutting
Stepped Cutting
.008-.012 .014-.016 .020-.026 .020-.030
.004-.006 .006-.008 .012-.016 .012-.020
Power Consumption The power curve of the machine should be consulted and cutting data values adjusted accordingly. • HP Requirements = MRR x K • MRR = d x SFM x IPR x 12 • MRR = metal removal rate, cubic inches
Material
K Factor*
Steel
.750
Alloy Steel Cast Iron Aluminum
1.000
.650 .430
• d = radial depth of cut, inches • SFM = surface feet/minute • IPR = inches/rev
High Temp Alloys
2.000
*With positive cutting geometry only
General Rule: Boring bar (ØD 2 ) should always be smaller than original hole size (ØD 1 ).
L 2
It is very important to allow for clearance between boring bar and rough bore diameter. ! CAUTION
L 1
444
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