sp3 endmill vs. Jabro |
Wear life: A Jabro 1/2-inch endmill and an sp3
endmill were compared, with a bare carbide endmill serving as a reference. Poco
3 graphite was cut at 1300 sfm using a tooth load of 0.002 in. and 0.025 in.
depth of cut. For the purpose of life testing it was assumed that a tool is
worn out when flank wear reaches 0.005 in. on the cutting edge.
 The bare
carbide tool ran about 20 minutes until it was worn out, the Jabro tool ran
about 220 minutes, and the sp3 tool ran about 570 minutes, or 2-1/2
times longer than the Jabro tool.
Tolerance: To compare tool
tolerance the diameters of the Jabro and sp3 tools were measured as a
function of time in cut. Measurements were made with a calibrated precision
micrometer, and on an optical comparator.
sp3
grinds all of its tools slightly undersize and carefully coats the tools up to
the nominal diameter.
The sp3
tool was nominally 0.5000 inches in diameter at the start of the test whereas
the Jabro tool was 0.4990 – very close to the limit of their published
tolerance. As the test progressed, the Jabro tool exhibited a larger change in
diameter for the same time in cut. When the Jabro tool was worn out at 220
minutes the diameter had been reduced to 0.4970, well out of their published
tolerance limits. The sp3 tool at 500 minutes had a diameter of 0.4987,
which is 65% of the dimensional change of the Jabro tool after more than twice
the cutting time.
Tool tolerance
is an extremely important consideration in maintaining workpiece dimensional
integrity. |
| Test data: Tool wear lifeTool tolerance (diameter wear) |
|
sp3 CVD diamond vs. DLC and TiAlN |
Tools with different types of coating from three manufacturers
were compared with an sp3 tool. The tool style tested was a 1/4-inch
endmill. EDM graphite was machined at 9000 rpm, 0.002 in/tooth feed, and 0.050
in. depth of cut. The flank wear was measured for each tool at intervals of 148
in. cut length in order to plot the wear rate. Tool life was defined as 0.004
in. of flank wear.
The TiAlN
coated tool and the Data Flute DLC coated tools reached end of life at about 20
and 25 minutes respectively; the Tetrabond DLC coated tool was worn out at
about 70 minutes. The sp3 tool reached end of life at about 310 minutes,
demonstrating well over 4 times the life of the Tetrabond tool. |
| Test data: Machining graphite: wear test
comparison |
|
Machining MMCs and high silicon aluminum |
sp3’s MAC 20
insert grade is suited to milling and turning high silicon aluminum (silicon
content of 12% or higher) and Metal Matrix Composites. Milling tests on 390
aluminum with DIAbide tools have demonstrated wear life from equal to PCD to 3
times PCD. When milling DURALCAN, wear life of the DIAbide tool is about
7 times PCD. These figures do not take into account the multiple tips of
sp3 inserts.
Turning tests
on DURALCAN have shown DIAbide wear life is 3 times that of PCD. |
| Test data: Typical milling and
turning results |
|
sp3’s tool testing program |
| If you have any questions about tests described here, please call
sp3. We maintain a dedicated test facility to support ongoing
improvement of our products. |
 |
| |
| |
