The Sandvik Coromant SCMT GC4225 carbide indexable turning insert with PR, UR, PM, UM, PF, or UF chipbreaker has a square shape with a 7-degree clearance angle, and provides a balance of wear and shock resistance for turning of steel in difficult to good machining conditions. The single-sided positive insert has chip grooves on one side, a countersunk hole in the center, and four cutting edges. It has a 7-degree clearance angle for light cutting forces and side clearance, making it better than a negative insert for internal turning. It can also be used for roughing, facing, interrupted cuts, and large lead angles. The GC4225 grade is a combination of carbide and a coating of TiCN, aluminum oxide, and TiN applied through medium temperature chemical vapor deposition (MTCVD). It provides a balance of hardness and toughness for wear and shock resistance when turning steel. MTCVD coatings are deposited at lower temperatures than CVD coatings. The lower temperatures eliminate cracks in the coating and provide increased toughness and smoothness without limiting wear resistance. The coating also provides shock resistance during interrupted cuts.
The SCMT GC4225 is available with a choice of six chipbreakers: PR, UR, PM, UM, PF, or UF. The PR and UR chipbreaker styles are designed for high cutting depths and feed rates when roughing steel. The UR chipbreaker style has a broader feed rate range and cutting depth range than the PR chipbreaker style. The PM and UM chipbreaker styles are designed for medium machining of steel. The PM chipbreaker style has a broader feed rate range than the UM chipbreaker, whereas the UM chipbreaker style has a broader cutting depth range than the PM chipbreaker style. The PM and UM chipbreaker styles offer a wider range of cutting depth and feed rate combinations than the PF and UF chipbreakers, which are designed for low cutting depths and low feeds when finishing steel. Tolerance of distance from the outer edge of the inscribed circle to the point of the square is + or - 0.002” to 0.005” and tolerance of the theoretical diameter of the insert is + or - 0.002” to 0.005”. Insert thickness tolerance is + or - 0.005”. Different insert shapes and sizes may have different inscribed circle (iC) measurements, which are related to the insert’s range of cutting depths, speeds, lead angle, and feed rates. The inscribed circle is the largest circle that can be drawn within the edges of the insert shape. In general, as the insert size and iC become larger, the maximum cutting depth increases. The cutting depth influences the metal removal rate, number of cuts, chip evacuation, and power required when using the insert.
Indexable inserts are small cutting tools designed to remove material in external and internal cutting applications such as turning, milling, drilling, and grooving. They are held by an insert holder, have multiple cutting edges, and can be rotated when one edge wears down. Multiple inserts can be used to accomplish a variety of cuts in one operation. An insert is either positive or negative, which refers to the rake or clearance angle at which the insert removes material. Inserts are coded according to their specific cutting and application capability (e.g., VNMG 16 04 04-QM). Each part of the code represents details of the insert shape, nose angle, clearance angle, tolerance, size, geometry, grade, and chipbreaker style.
Sandvik Coromant produces tools for turning, milling, and drilling. Headquartered in Sweden and represented in 130 countries, the company manufactures tools used throughout the metalworking field, including the automotive and aerospace, die and mould, and general engineering industries. All Sandvik Coromant inserts meet ISO and ANSI standards. Matching Inserts to Holders
These inserts are part of the Sandvik Coromant 107 Positive Insert family, which means they can be used in the CoroTurn 107 clamping system. The CoroTurn 107 system is used for internal longitudinal turning of small diameters, and is also for external light roughing to finishing.