TURNING INSERT - NEGATIVE_SNMG
Caution
Product Description
Dormer Pramet SNMG 090308E-M:T9415 (ANSI SNMG 322-M:T9415) is a double-sided square negative turning insert with M chipbreaker and rounded cutting edges. Grade T9415 is an MT-CVD coated, functionally graded WC-Co carbide within ISO range P05 - P30, designed for fine to heavy machining of steels.
ISO Designation (ISO 1832)
- S: square insert with 90° corner angle
- N: 0° clearance angle (negative insert)
- M: tolerance class M
- G: cylindrical fixing hole with chipbreaker on both faces
- 09: cutting edge length 9.525 mm
- 03: insert thickness 3.18 mm
- 08: corner radius 0.8 mm
- E: rounded cutting edge
- M: Dormer Pramet chipbreaker designation
- T9415: Dormer Pramet grade
Workpiece Material Groups (ISO 513)
- P - steel and cast steel: primary use (P05 - P30)
- K - cast iron: possible use
- H - hardened materials: possible use
Usage Notes
- Use with negative turning holders designed for SNMG inserts of size 09 and 3.18 mm thickness.
- Clean the insert seat and clamping surfaces before mounting or indexing so the ground seating face is fully supported.
- Index to a fresh edge before flank wear becomes excessive; the gold TiN top layer makes used edges easy to identify.
- Select cutting speed, feed and depth of cut according to Dormer Pramet recommendations for the workpiece material and machine condition.
- Wear safety glasses and keep chip guards in place, as hot chips and broken carbide fragments can cause injury.
The SNMG 090308E-M:T9415 from Dormer Pramet is a double-sided negative turning insert with a square shape, an inscribed circle diameter of 9.525 mm, a thickness of 3.18 mm and a 0.8 mm nose radius. It is produced to ISO tolerance class M and carries the M chipbreaker with rounded cutting edges on both faces, giving 8 cutting edges per insert for economical external turning and facing on CNC and conventional lathes.
Grade T9415 is the fourth-generation MT-CVD turning grade from Dormer Pramet. It replaces the previous T9310 and T9315 grades and partly overlaps with T9325, giving it one of the widest application ranges in steel turning.
Key Features
- MT-CVD coating 30% thicker than the previous generation for higher wear resistance and higher cutting speeds.
- New post-treatment process improves the toughness and stability of the cutting edge, giving reliable performance in interrupted cuts and unstable conditions.
- Seating face ground after coating for better seating stability and improved heat transfer away from the cutting edge, reducing plastic deformation wear.
- Gold TiN top layer makes flank wear easy to detect.
- Optimized cutting-edge geometry reduces cutting forces.
- Strong 90° square corner and negative geometry for high edge security.
Applications
- Primary use: steel and cast steel (ISO P).
- Possible use: cast iron (ISO K) and hardened materials (ISO H).
- Fine to heavy external turning and facing.
| Brand | Dormer Pramet |
|---|---|
| Product name (ISO) | SNMG 090308E-M:T9415 |
| Ordering code (ANSI) | SNMG 322-M:T9415 |
| Insert shape | S - square, 90° corner angle |
| Insert geometry | Negative, double-sided |
| Clearance angle | N - 0° |
| Tolerance class | M |
| Insert type | G - fixing hole, chipbreaker on both faces |
| Chipbreaker | M, rounded cutting edges |
| Grade | T9415 |
| Substrate | Functionally graded WC-Co carbide |
| Coating | MT-CVD |
| ISO application range | P05 - P30 |
| Workpiece material | P primary use; K, H possible use |
| Inscribed circle diameter (IC) | 9.525 mm (0.375 inch) |
| Insert thickness (S) | 3.18 mm (0.125 inch) |
| Corner radius (RE) | 0.8 mm (0.031 inch) |
| Cutting edge length (L) | 9.525 mm |
| Fixing hole diameter (D1) | 3.81 mm |
| Number of cutting edges | 8 |
| Machining operation | Fine to heavy machining of steels |
| Product name (ISO) | Ordering code (ANSI) | Grade | Chipbreaker | IC (mm) | S (mm) | RE (mm) | L (mm) | D1 (mm) |
|---|---|---|---|---|---|---|---|---|
| SNMG 090308E-M:T9415 | SNMG 322-M:T9415 | T9415 | M | 9.525 | 3.18 | 0.8 | 9.525 | 3.81 |
Top view: a square negative insert with four equal cutting edges, each 9.525 mm long (L), meeting at 90° corners. Each corner is rounded with a 0.8 mm nose radius (RE). The inscribed circle diameter (IC) is 9.525 mm.
A cylindrical fixing hole with a diameter of 3.81 mm (D1) passes through the centre of the insert for clamping in the tool holder.
Side view: the insert thickness (S) is 3.18 mm. The side flanks are perpendicular to the top and bottom faces (0° clearance angle), and the M chipbreaker is formed on both faces, so the insert can be turned over to use 8 cutting edges in total.
Choosing the Chipbreaker (SNMG, Grade T9415)
- FM: fine to medium machining of steels, the first choice for finishing.
- M: fine to heavy machining of steels, covering the widest range of the three.
- NRM: medium to heavy machining of steels.
Choosing the Grade
- T9415 (P05 - P30): first choice for most steel turning operations, highly wear-resistant and also suitable for interrupted cuts.
- T9325 (P15 - P35): MT-CVD grade covering a tougher application range in steels.
- T9335 (P20 - P45): MT-CVD grade toward the tough end of the steel range.
- T7325: first choice and most versatile grade for turning stainless steels (ISO M).
Why Choose a Square Insert
- The 90° corner is stronger than 80° or 55° rhombic corners and the double-sided design gives 8 cutting edges, making SNMG an economical choice for roughing and general turning.
- Square inserts are normally used in holders with 45° or 75° approach angles for turning, facing and chamfering; they cannot finish a 90° shoulder.
- Corner radius: a smaller radius lowers cutting forces and vibration on slender parts, while a larger radius strengthens the corner and allows higher feeds. The 0.8 mm radius is a common general-purpose size.