The Sandvik Coromant VNMG GC3205 carbide indexable insert with KM chipbreaker has a diamond shape (also called rhombic) with a 35-degree cutting angle, providing a balance of wear and shock resistance for light roughing to medium machining of gray cast iron. This double-sided negative insert has chip grooves on both sides, a hole in the center, and four cutting edges. It has strong edges, zero clearance, and is a better choice for external turning than a positive insert. A combination of fine-grained carbide with a thin titanium carbonitride (TiCN), aluminum oxide, and titanium nitride (TiN) coating applied through Medium Temperature Chemical Vapor Deposition (MTCVD) provides better wear-resistance and toughness for turning cast iron than uncoated carbide inserts. MTCVD coatings provide increased toughness and smoothness without limiting wear resistance.
The VNMG GC3205 has a KM chipbreaker designed for light roughing to medium machining of gray cast iron in average machining conditions. Tolerance of distance from outer edge of inscribed circle to point of diamond is + or - 0.002 to 0.005”. 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, 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 TMax P Negative Insert family, which means they can be used with CoroTurn RC, a clamp-style insert holding system. This system is for use when stability and security are essential for productive turning of large components. The system is mostly used for external turning, from roughing to finishing, but also for internal turning.