Mitsubishi MMT16IRA55-S VP15TF Internal Threading Insert
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MMT16IRA55-S VP15TF
Mitsubishi Materials | Internal Partial Profile 55° (Whitworth / BSP / BSW)
The Mitsubishi MMT16IRA55-S VP15TF is a high-precision internal threading insert designed for 55-degree Whitworth profiles. As a partial profile A-type insert, it offers maximum flexibility, allowing for a pitch range of 0.5mm to 1.5mm (48 to 16 TPI). This versatility makes it the primary tool for CNC threading of internal pipe threads (G/RP) and Whitworth fasteners. Engineered with the -S type 3D molded chipbreaker and the legendary VP15TF Miracle PVD coating, it provides superior chip evacuation in deep-hole internal threading operations, especially when machining stainless steel and tough alloys.
Technical Specifications
| ISO/Metric Designation | MMT16IRA55-S |
|---|---|
| Thread Profile | 55° Partial Profile (Internal) |
| Pitch Range | 0.5 - 1.5 mm / 48 - 16 TPI |
| Insert Size (IC) | 9.525 mm (3/8") |
| Grade / Coating | VP15TF (Miracle Al-Ti-N PVD) |
VP15TF Miracle Grade
The VP15TF grade utilizes a micro-grain carbide substrate with a proprietary Miracle (Al-Ti-N) PVD coating. It is the world-standard for indexable threading due to its extreme resistance to built-up edge (BUE) and heat-induced flank wear. This grade ensures longevity even when threading gummy materials like 316 stainless steel.
-S Type 3D Chipbreaker
Internal threading is prone to chip clogging. The -S molded chipbreaker features a specialized 3D rake that forces chips to curl into tight spirals, allowing the internal boring bar's coolant to flush them out effortlessly. This prevents "chip nesting" and ensures a high-quality thread surface finish.
Recommended Cutting Parameters
| Workpiece Material | Cutting Speed ($v_c$) | Typical No. of Passes |
|---|---|---|
| Carbon Steel (S45C) | 90 - 160 m/min | 6 - 12 |
| Stainless Steel (304/316) | 70 - 130 m/min | 8 - 14 |
| Alloy Steel (SCM440) | 80 - 140 m/min | 7 - 13 |
MMTIR INTERNAL TOOLING SYSTEM
This 16IR insert is optimized for Mitsubishi MMTIR internal boring bars and standard 16mm threading holders.
Shop MMTIR Internal Bars →Metric vs. Inch Cross-Reference
| Feature | Metric Designation | Inch Designation (ANSI) |
|---|---|---|
| Insert Size | 16 IR | 16IR (3/8" Inscribed Circle) |
| Max Pitch | 1.5 mm | 16 TPI |