# Denitool® Countersink Cutter (CounterSink T), 90° (ISO) and 82° (ANSI)

Source: https://www.denitool.com/en/countersink-cutter.html
Curated Markdown for AI agents. Prices and availability: live via the Store API, see https://www.denitool.com/llms.txt

The Denitool Countersink Cutter (catalog family name **CounterSink T**) is an indexable milling cutter for **countersinks** (conical chamfers on hole edges, for example for countersunk screw heads). It is used on milling machines and machining centers.

- **90° countersinks (ISO):** style **RTDS**, tool cutting edge angle KAPR 45°. Available with metric shank (⌀ 20 mm) and inch shank (⌀ .750").
- **82° countersinks (ANSI):** style **RTXS**, KAPR 49°. Inch program only (shank ⌀ .750").
- Countersink diameters from ⌀ 6.50 mm (.256") up to ⌀ 31.24 mm (1.230"), depending on cutter size and insert corner radius (tables below).
- Two effective teeth (z = 2). Each tooth is a 60° triangular (T) indexable insert, held by a screw: size **TP 1102** (styles ending in -11) or **TP 16T3** (styles ending in -16).
- Cylindrical steel shank with Weldon flat. No internal coolant.

The product description says the optimized geometry gives a vibration-free, soft cut, so a separate deburring operation afterwards is not needed. The inserts are also designed for recurring diameters and work well without coolant.

Denitool is made by DENI AG (Veltheim, Switzerland) and its subsidiary Denitool Inc. (Raleigh NC, inch program).

![Denitool Countersink Cutter](https://www.denitool.com/assets/images/7/Countersink%20Cutter-0ee2bc77.png)

Header image of the page: a Denitool countersink cutter.

## Terms used on this page

- **Countersink angle**: the included angle of the cone that the cutter produces: 90° (ISO) or 82° (ANSI, common for inch countersunk screws).
- **KAPR**: tool cutting edge angle (ISO 13399). Countersink angle = 2 × (90° − KAPR): KAPR 45° gives 90°, KAPR 49° gives 82°. The inch catalog writes this angle as χ.
- **⌀D**: largest countersink diameter the cutter produces (outer end of the cutting edge).
- **⌀d**: smallest diameter of the cutting edge at the tip (the countersink starts here).
- **ap**: maximum axial depth of cut of the countersink cone. For a 90° cutter D − d = 2 × ap.
- **L**: overall length. **H**: head length (length of the cutting head in front of the shank). **⌀A**: shank diameter.
- **z**: number of teeth (inserts in the cut).
- **r**: corner radius of the insert. The cutting diameters depend on it: an insert with a larger corner radius gives a smaller ⌀D and a larger ⌀d.
- **Inch mark**: a designation with an inch mark after "FW" (for example FW "0612 RTDS-11) is an inch-shank article. In the shops it is written with a typographic quote sign (CH shop: FW ”0612 RTDS-11, US shop: FW “0612 RTDS-11).
- Designation suffix **-11 / -16**: insert size TP 1102 (11 mm cutting edge length) or TP 16T3 (16.5 mm).
- Designation number: in these articles the last two digits of the number give the shank: 20 = ⌀ 20 mm (metric), 12 = 12/16" = 3/4" = ⌀ .750" (19.05 mm, inch).

## Article overview

| Designation | Countersink angle | KAPR | Shank ⌀A | Insert size | Insert screw | Torx driver | Listed in shop |
|---|---|---|---|---|---|---|---|
| FW 0720 RTDS-11 | 90° | 45° | 20 mm (.787") | TP 1102 | T25.055 | T7F | CH, US |
| FW 0920 RTDS-16 | 90° | 45° | 20 mm (.787") | TP 16T3 | T35.084 | T15H | CH, US |
| FW "0612 RTDS-11 | 90° | 45° | .750" (19.05 mm) | TP 1102 | T25.055 | T7F | CH, US |
| FW "0912 RTDS-16 | 90° | 45° | .750" (19.05 mm) | TP 16T3 | T35.084 | T15H | CH, US |
| FW "0812 RTXS-11 | 82° | 49° | .750" (19.05 mm) | TP 1102 | T25.055 | T7F | CH, US |
| FW "1112 RTXS-16 | 82° | 49° | .750" (19.05 mm) | TP 16T3 | T35.084 | T15H | CH, US |

All six are right-hand cutters (right-hand rotation) with 2 teeth. FW "0612 RTDS-11 and FW "0912 RTDS-16 are the inch-shank versions of FW 0720 RTDS-11 and FW 0920 RTDS-16 with the same cutting geometry.

## Metric cutters, 90° (dimensions in mm, inch in brackets)

Values from the metric catalog embedded on the page. ⌀D, ⌀d and ap depend on the insert corner radius r.

| Designation | Insert r | ⌀D | ⌀d | ap | L | H | z | ⌀A |
|---|---|---|---|---|---|---|---|---|
| FW 0720 RTDS-11 | 0.2 | 20.75 (.817") | 6.50 (.256") | 7.13 (.281") | 76 (2.992") | 26 (1.024") | 2 | 20 (.787") |
| FW 0720 RTDS-11 | 0.4 | 20.27 (.798") | 6.93 (.273") | 6.65 (.262") | 76 | 26 | 2 | 20 |
| FW 0720 RTDS-11 | 0.8 | 19.27 (.759") | 7.82 (.308") | 5.72 (.225") | 76 | 26 | 2 | 20 |
| FW 0920 RTDS-16 | 0.4 | 31.24 (1.230") | 9.98 (.393") | 10.63 (.419") | 85 (3.346") | 35 (1.378") | 2 | 20 (.787") |
| FW 0920 RTDS-16 | 0.8 | see note | 10.88 (.428") | see note | 85 | 35 | 2 | 20 |

Note on FW 0920 RTDS-16 with r 0.8: the metric catalog gives ⌀D 31.98 mm and ap 11.06 mm, which contradicts the 90° geometry (D − d must equal 2 × ap) and the trend of the other rows. The inch catalog gives for the same cutting geometry (FW "0912 RTDS-16) ⌀D 1.182" (30.02 mm), ⌀d .428" (10.87 mm), ap .376" (9.55 mm), which is consistent. Use the inch-catalog values or confirm with Denitool support. For r 0.4 the inch catalog also gives a slightly different ⌀D (1.220", 30.99 mm) and ap (.414", 10.52 mm).

TP 16T3 inserts have no r 0.2 version, so FW 0920 RTDS-16 is listed for r 0.4 and r 0.8 only.

## Inch cutters, 90° (RTDS) and 82° (RTXS) (dimensions in inch, mm in brackets)

Values from the inch catalog embedded on the page. Insert radius r .0079" = 0.2 mm, .0157" = 0.4 mm, .0315" = 0.8 mm.

| Designation | Angle | KAPR (χ) | Insert r | ⌀D | ⌀d | ap | L | H | z | ⌀A |
|---|---|---|---|---|---|---|---|---|---|---|
| FW "0612 RTDS-11 | 90° | 45° | .0079" | .817" (20.75) | .256" (6.50) | .281" (7.14) | 3.055" (77.60) | 1.024" (26.0) | 2 | .750" (19.05) |
| FW "0612 RTDS-11 | 90° | 45° | .0157" | .798" (20.27) | .273" (6.93) | .262" (6.65) | 3.055" | 1.024" | 2 | .750" |
| FW "0612 RTDS-11 | 90° | 45° | .0315" | .759" (19.28) | .308" (7.82) | .225" (5.72) | 3.055" | 1.024" | 2 | .750" |
| FW "0812 RTXS-11 | 82° | 49° | .0079" | .845" (21.46) | .323" (8.20) | .301" (7.65) | 3.016" (76.61) | .948" (24.08) | 2 | .750" (19.05) |
| FW "0812 RTXS-11 | 82° | 49° | .0157" | .827" (21.01) | .340" (8.64) | .281" (7.14) | 3.016" | .948" | 2 | .750" |
| FW "0812 RTXS-11 | 82° | 49° | .0315" | .791" (20.09) | .373" (9.47) | .240" (6.10) | 3.016" | .948" | 2 | .750" |
| FW "0912 RTDS-16 | 90° | 45° | .0157" | 1.220" (30.99) | .393" (9.98) | .414" (10.52) | 3.409" (86.59) | 1.378" (35.0) | 2 | .750" (19.05) |
| FW "0912 RTDS-16 | 90° | 45° | .0315" | 1.182" (30.02) | .428" (10.87) | .376" (9.55) | 3.409" | 1.378" | 2 | .750" |
| FW "1112 RTXS-16 | 82° | 49° | .0157" | 1.227" (31.17) | .455" (11.56) | .443" (11.25) | 3.409" (86.59) | 1.378" (35.0) | 2 | .750" (19.05) |
| FW "1112 RTXS-16 | 82° | 49° | .0315" | 1.191" (30.25) | .489" (12.42) | .403" (10.24) | 3.409" | 1.378" | 2 | .750" |

Countersink ranges given in the inch catalog with the insert named there: FW "0612 RTDS-11 with TPHW 110204 EN DP55 for countersink diameters .273" to .798" (6.93 to 20.27 mm); FW "0912 RTDS-16 with TPHW 16T308 EN DP55 for .428" to 1.182" (10.87 to 30.02 mm).

## Inserts

The cutters take 60° triangular inserts with 11° clearance: TP.. 1102.. (styles -11) and TP.. 16T3.. (styles -16). The metric catalog refers to the insert table of the Denitool corner and face milling cutters (FaceCut T), the inch catalog to its insert pages. The catalog example for the countersink cutters is **TPHW .. EN DP55** (TPHW 110204 EN DP55, TPHW 16T308 EN DP55).

| Insert size | Cutting edge length l | Inscribed circle d | Thickness s | Corner radii available |
|---|---|---|---|---|
| TP 1102.. | 11 mm (.433") | 6.35 mm (.250") | 2.38 mm (.094") | 0.2, 0.4, 0.8 mm (1102 02, 04, 08) |
| TP 16T3.. | 16.5 mm (.650") | 9.52 mm (.375") | 3.97 mm (.156") | 0.4, 0.8 mm (16T3 04, 08) |

Insert types listed in the catalog insert table for these seats, and confirmed in the shops:

| Insert type | Edge / hand | Grades in the shop |
|---|---|---|
| TPHW .. EN | honed edge (E), neutral (N), no chip breaker | P25, DP25, DP35, DP55 |
| TPHW .. FN | sharp edge (F), neutral (N), no chip breaker | DX2, DX20, DX30, DX50 |
| TPHT .. ER / EL | honed edge, right / left hand | P25, DP25, DP35, DP55 |
| TPHT .. FR / FL | sharp edge, right / left hand | DX2, DX20, DX30 (CH shop also TPHT 110202 FR DX50) |

Grade short guide (from the Denitool insert grades page): P25 and DX2 are uncoated carbide; DP25/DX20 (yellow PVD) for steel, free-cutting stainless steel and superalloys; DP35/DX30 (grey PVD) for steel, difficult stainless steel and cast iron; DP55/DX50 (black PVD) with high thermal stability, excellent for dry machining. Details: https://www.denitool.com/md/en/insert-grades.md and https://www.denitool.com/md/en/insert-designation.md

## Screws, drivers and tightening torque

| Insert size | Insert screw | Thread | Torx | Tightening torque | Driver |
|---|---|---|---|---|---|
| TP 1102 (-11 cutters) | T25.055 | M2.5 | T7 | 1.30 Nm (11.5 lbf·in) | T7F (flag-type Torx T7 driver) |
| TP 16T3 (-16 cutters) | T35.084 | M3.5 | T15 | 3.40 Nm (30.1 lbf·in) | T15H (Torx T15 screwdriver) |

Source of the torques: https://www.denitool.com/md/en/tightening-torque.md

## Catalog pages (embedded on the human page)

- Metric catalog pages (CounterSink T, pages 91 to 92, plus the FaceCut T insert table): https://drive.google.com/file/d/0B0FVd0DDs6fFVzFMbEFkUzl3elk/preview
- Inch catalog pages (Denitool Inc., CounterSink T, pages 90 to 91): https://drive.google.com/file/d/0B0FVd0DDs6fFREFfdUEzQzdEdHM/preview

## Find and order (Store API)

Search by the style letters. Examples that return results:

```
curl "https://ch.denitool.com/wp-json/wc/store/v1/products?search=FW%200720%20RTDS-11"
curl "https://ch.denitool.com/wp-json/wc/store/v1/products?search=RTXS"
curl "https://store.denitool.com/wp-json/wc/store/v1/products?search=RTXS"
curl "https://store.denitool.com/wp-json/wc/store/v1/products?search=TPHW%20110204%20EN"
```

`ch.denitool.com` is the Swiss shop (Switzerland and Liechtenstein), `store.denitool.com` the US shop (Denitool Inc.). The response lists products with name (the designation), price and stock status. Note: `search=RTDS` also returns the RTDS face milling cutters (FW 1616 RTDS-11 up to FW 3225 RTDS-16, in the US shop also the inch versions FW “2512 to “3216 RTDS-16) and, in the CH shop, FC ... RTDS-11 live tools. These are not countersink cutters; the countersink cutters are only the six designations listed above. Inch designations carry an inch mark that the API returns encoded (e.g. `FW ”1112 RTXS-16` or `FW “1112 RTXS-16`); search by the style letters instead of typing the mark. Screws: `search=T25.055`, `search=T35.084` (both shops). Drivers: `search=T7F`, `search=T15H` (CH shop only; the US shop returns no product for them).

## Related pages

- Product overview: https://www.denitool.com/md/en/products.md
- Indexable milling overview: https://www.denitool.com/md/en/indexable-milling.md
- MicroCut F (chamfer milling in small bores): https://www.denitool.com/md/en/microcut-f.md
- MicroMill: https://www.denitool.com/md/en/micromill.md
- Corner and Face Milling Cutter: https://www.denitool.com/md/en/corner-and-face-milling-cutter.md
- MillingCutters (face milling cutters with the same TP inserts): https://www.denitool.com/md/en/millingcutters.md
- Slot Milling Cutter: https://www.denitool.com/md/en/slot-milling-cutter.md
- Turning 60° (same TP 1102 / TP 16T3 inserts): https://www.denitool.com/md/en/turning-60.md
- System Tools for Live Tooling: https://www.denitool.com/md/en/system-tools-for-live-tooling.md
- Holemaking: https://www.denitool.com/md/en/holemaking.md
- Tooling systems: https://www.denitool.com/md/en/tooling-systems.md
- Insert designation: https://www.denitool.com/md/en/insert-designation.md
- Insert grades: https://www.denitool.com/md/en/insert-grades.md
- Tightening torque: https://www.denitool.com/md/en/tightening-torque.md
- Downloads (catalogs): https://www.denitool.com/md/en/downloads.md
- Services: https://www.denitool.com/md/en/services.md
- Support: https://www.denitool.com/md/en/support.md
- Company: https://www.denitool.com/md/en/denitool-company.md