TURNING INSERT - EXTERNAL GROOVING_TN R EXT
Caution
Product Description
Pramet TN 16EL-R050:T8330 is a left-hand, full-radius external grooving insert from the Dormer Pramet TN R EXT series. It is used for turning O-ring and circlip grooves on outside diameters. It has a 0.5 mm corner radius, 1.00 mm cutting width and 1.3 mm maximum cutting depth, in PVD-coated grade T8330 for steel, stainless steel and cast iron.
Application
External, left-hand turning of O-ring and circlip (Seeger ring) grooves on continuous surfaces. Use with Pramet left-hand external toolholders for TN 16 inserts (SEL series).
Recommended starting cutting data (grade T8330)
| ISO material group | Cutting speed vc (m/min) | Feed f (mm/rev) |
|---|---|---|
| P - Steel | 130 | 0.06 |
| M - Stainless steel | 75 | 0.05 |
| K - Cast iron | 120 | 0.06 |
The manufacturer catalogue gives no cutting data for ISO N (non-ferrous metals), ISO S (heat-resistant superalloys and titanium) or ISO H (hardened steel) for this insert.
Usage notes
- The cutting data above are starting values. Adjust them to suit machine rigidity, workpiece clamping and tool overhang.
- Coolant has a very positive effect on tool life and is recommended.
- The series is specified for continuous surfaces, so avoid interrupted cuts.
- Match the insert hand to the holder: EL inserts fit left-hand SEL holders, and ER inserts fit right-hand SER holders.
- Clean the insert seat and tighten the clamping screw securely before machining.
The TN R EXT series from Dormer Pramet (Pramet brand) consists of single-sided triangular laydown inserts with a full-radius cutting edge. They are used for external grooving of O-ring and circlip (Seeger ring) grooves on continuous surfaces. TN 16EL-R050:T8330 is the left-hand version in insert size 16 (inscribed circle 9.525 mm), and it produces a groove with a 0.5 mm radius and 1.00 mm width.
Key features
- Full-radius profile (RE 0.5 mm) for round-bottom grooves such as O-ring seats
- Cutting width 1.00 mm with a tolerance of 0.00 / +0.05 mm
- Maximum cutting depth 1.3 mm
- Grade T8330: fine-grained (sub-micron) WC-Co carbide substrate with a relatively high cobalt content and a nano-layered PVD coating with gradient transitions
- Gold-coloured surface
- Mounts in Pramet left-hand external toolholders for TN 16 inserts (SEL series), the same holders used for external threading
Typical applications
- Turning O-ring grooves on shafts and other outside diameters
- Turning circlip (retaining ring) grooves on outside diameters
- Machining steel (ISO P), stainless steel (ISO M) and cast iron (ISO K)
| Brand | Dormer Pramet (Pramet) |
|---|---|
| Series | TN R EXT |
| Designation | TN 16EL-R050:T8330 |
| Article No. | 6755977 |
| Insert type | Triangular, single-sided, full-radius external grooving insert |
| Hand | Left hand (L) |
| Insert size / IC | 16 / 9.525 mm (0.375 inch) |
| Insert thickness (S) | 3.58 mm (0.141 inch) |
| Fixing hole diameter (D1) | 3.90 mm (0.154 inch) |
| Corner radius (RE) | 0.5 mm (0.02 inch) |
| Cutting width (CW) | 1.00 mm |
| Cutting width tolerance | 0.00 / +0.05 mm |
| Maximum cutting depth (CDX) | 1.3 mm |
| Substrate | Fine-grained WC-Co carbide |
| Grade / coating | T8330, PVD coated |
| ISO application range | P25-P40, M20-M35, K20-K40 |
| Compatible toolholder | Left-hand external toolholders for TN 16 inserts (e.g. SEL 2020 K 16, SEL 2525 M 16) |
| Pack quantity | 5 pcs |
| Designation | Hand | Grade | IC (mm) | S (mm) | D1 (mm) | RE (mm) | CW (mm) | CDX (mm) |
|---|---|---|---|---|---|---|---|---|
| TN 16ER-R050 | Right | T8330 | 9.525 | 3.58 | 3.90 | 0.5 | 1.00 | 1.3 |
| TN 16ER-R100 | Right | T8330 | 9.525 | 3.58 | 3.90 | 1.0 | 2.00 | 1.85 |
| TN 22ER-R150 | Right | T8330 | 12.700 | 4.70 | 4.90 | 1.5 | 3.00 | 2.2 |
| TN 16EL-R050 | Left | T8330 | 9.525 | 3.58 | 3.90 | 0.5 | 1.00 | 1.3 |
| TN 16EL-R100 | Left | T8330 | 9.525 | 3.58 | 3.90 | 1.0 | 2.00 | 1.85 |
| TN 22EL-R150 | Left | T8330 | 12.700 | 4.70 | 4.90 | 1.5 | 3.00 | 2.2 |
Cutting width tolerance for all models: 0.00 / +0.05 mm. This series page covers TN 16EL-R050:T8330 (left hand, RE 0.5 mm). The other models are shown for reference.
Triangular laydown insert with a central fixing hole and a full-radius cutting tip (left-hand version, TN 16EL-R050):
- Inscribed circle (IC): 9.525 mm
- Insert thickness (S): 3.58 mm
- Fixing hole diameter (D1): 3.90 mm
- Corner radius of the cutting tip (RE): 0.5 mm
- Cutting width (CW): 1.00 mm, tolerance 0.00 / +0.05 mm
- Maximum cutting depth (CDX): 1.3 mm
How to choose within the TN R EXT series
- Insert hand: choose EL (left hand) for SEL holders or ER (right hand) for SER holders, according to the feed direction and the machine setup.
- Groove radius and width: RE 0.5 mm gives CW 1.00 mm, RE 1.0 mm gives CW 2.00 mm and RE 1.5 mm gives CW 3.00 mm. Select the radius that matches the groove bottom radius on the drawing.
- Groove depth: maximum cutting depth is 1.3 mm for RE 0.5 mm, 1.85 mm for RE 1.0 mm and 2.2 mm for RE 1.5 mm.
- Insert size: size 16 (IC 9.525 mm) fits holders for TN 16 inserts, and size 22 (IC 12.700 mm) fits holders for TN 22 inserts.
- Flat-bottom grooves: for square-bottom circlip grooves, consider the TN ZZ EXT series instead.
Choosing by workpiece material
- Steel (ISO P): vc 130 m/min, f 0.06 mm/rev.
- Cast iron (ISO K): vc 120 m/min, f 0.06 mm/rev.
- Stainless steel (ISO M): lower the speed to vc 75 m/min and the feed to f 0.05 mm/rev.
- Non-ferrous metals, superalloys, titanium and hardened steel: the catalogue has no data for this insert, so contact Dormer Pramet for a recommendation.