Mitsubishi MMT16IRG55-S VP15TF Internal Threading Insert
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MMT16IRG55-S VP15TF
Mitsubishi Materials | Internal Partial Profile 55° G-Range (Whitworth / BSP / BSW)
The Mitsubishi MMT16IRG55-S VP15TF is a heavy-duty internal threading insert engineered for coarse 55-degree profiles. The "G" designation indicates a specialized pitch range of 1.75mm to 3.0mm (14 to 8 TPI), making it the primary choice for CNC threading of large internal pipe threads (G/Rp) and heavy Whitworth fasteners. Equipped with the -S type 3D molded chipbreaker and the proprietary VP15TF Miracle PVD coating, this insert excels in threading stainless steel and high-tensile alloys where deep-bore chip control is the greatest challenge.
Technical Specifications
| ISO/Metric Designation | MMT16IRG55-S |
|---|---|
| Thread Profile | 55° Partial Profile (Internal) |
| Pitch Range (Metric) | 1.75 - 3.0 mm |
| Pitch Range (Inch) | 14 - 8 TPI |
| Grade / Coating | VP15TF (Miracle Al-Ti-N PVD) |
VP15TF Miracle Grade
The VP15TF grade is Mitsubishi's premium universal carbide solution. Its Miracle (Al-Ti-N) PVD coating provides extreme heat resistance and surface lubricity. This is critical for indexable threading in "gummy" materials like 304 or 316 stainless steel, as it effectively prevents built-up edge (BUE) and premature edge chipping.
-S Type 3D Chipbreaker
In internal operations, chips often nest inside the bore, causing tool breakage. The -S molded chipbreaker utilizes a high-rake 3D geometry to curl chips into tight, manageable "clocks" that are easily evacuated by the internal boring bar's coolant flow, ensuring a flawless thread surface finish.
Recommended Cutting Parameters
| Workpiece Material | Cutting Speed ($v_c$) | Number of Passes (Coarse) |
|---|---|---|
| Carbon Steel (S45C) | 90 - 160 m/min | 12 - 18 |
| Stainless Steel (SUS304) | 70 - 130 m/min | 14 - 22 |
| Alloy Steel (4140/SCM440) | 80 - 140 m/min | 13 - 20 |
MMTIR INTERNAL SYSTEM COMPATIBILITY
The 16IR G55 insert is optimized for use with Mitsubishi MMTIR internal boring bars.
Browse Internal Boring Bars →Metric vs. Inch Reference
| Feature | Metric Designation | Inch Designation (ANSI) |
|---|---|---|
| Insert Size | 16 IR | 16IR (3/8" Inscribed Circle) |
| Max Pitch Range | 1.75 - 3.0 mm | 14 - 8 TPI |