SUMIBORON for Powdered Metal Machining BN7500
Sintered Alloy
■ General Features High-density sintered micro-grained CBN grains provide good sharpness and wear resistance to produce an excellent machined face surface on powdered metals during finishing. Excellent sharpness and wear resistance for high-quality machined surfaces in powdered metal finishing. Achieves high-precision, high-efficiency machining of powdered metal
Surface finish using the BN7500
Surface nish using previous CBN
L
- The previous CBN left white blemishes on the machined surface, whereas the BN7500 leaves a better, glossy surface finish
■ Features
● Excellent for finishing of powdered metal Excellent machined surface quality and surface roughness.
● Available with 5 different types of edge treatment for machining sintered parts of any shape or hardness LF has a sharper edge designed specifically for machining powdered metal with minimal burr and improved machining precision. HS has a strengthened cutting edge for stable chipping resistance during interrupted cutting and finishing. Provides machining stability by reducing the variation in early milling surface roughness with the type emphasizing LE surface roughness. LS has an excellent balance of fracture resistance and sharpness, and supports finishing that includes light interrupted cutting.
■ Cutting Performance
● Finished Surface Roughness during Initial Machining
10
.0236
Previous CBN standard
0.8
Conventional CBN Sharp Edge
.0197
8
BN7500 Standard
LS Type
LF Type
LE Type
Standard
.0157
0.6
6
.0118
BN7500 LF Type Excellent surface roughness and stability
4
BN7500 LF Type 50% reduction in burr height
0.4
.0079
R Honing
Roughness Control Variations in Early Surface Roughness
2
.0039
No R Honing
0.2
Negative Land α = 15°
No Negative Land α = 0°
0
50
100
150
200
0
50
100
150
200
No. of Passes
No. of Passes
0
Part Material Tool Cat. No. Cutting Conditions
: : : Sintered Ferrous Alloy SMF4040 Equivalent (70HRB, Continuous Cutting) 2NU-CNGA432 v c = 660 SFM, f = .0039 IPR, a p = .0039” Wet
Part Material Tool Cat. No. Cutting Conditions
: : : Sintered Ferrous Alloy SMF4040 Equivalent (70HRB, Continuous Cutting) 2NU-CNGA432 v c = 660 SFM, f = .0039 IPR, a p = .0039” Wet
Able to control early surface roughness variations by applying R honing to the cutting edge.
■ Recommended Cutting Edge Treatment
● Feed and Burr Relationship
A
No R Honing (Burr Control Emphasised)
LF Type
B
LE Type
LS Type
When Withdrawn
Workpiece Rotation Direction
Standard
R Honing (Surface Roughness Emphasised)
- The LF type without R honing has a cutting edge sharpness superior to the LE type with R honing and can control burrs better. - For a feed rate of .0039 IPR or higher, the LS type has a cutting edge sharpness superior to the standard type and can control burrs better.
HS Type
LF Type
LE Type
LS Type
Standard
R Honing (Breakage Control Emphasised)
A Diagram
Heavy
Frequency of Interruption
Burr
E
W Honing
Standard
15° .12 mm
Edge Chipping
B Diagram
No
E = 0° (No Negative Land)
LF
Rake Face
Negative land width W
LE
E Negative land angle
Yes
LS
15° .07 mm 25° .05 mm
CBN
Part Material: VVT Facing Tool Cat. No.: 3NU-TNGA331 Cutting Conditions: v
Honing
HS
Flank
c = 660 SFM,
f = .0039 IPR, a
p = .0039” Wet
L19
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