Toolholder and boring bar designation
Type a toolholder code (PCLNR 2020K12) or a boring bar code (S20R-SCLCR09) to see what each character means and which insert fits.
Quick answer
PCLNR 2020K12: P — lever lock, C — 80° diamond insert, L — 95° approach angle, N — 0° clearance insert, R — right hand, 2020 — 20 × 20 mm shank, K — 125 mm long, 12 — insert size. It takes CNMG 1204.. inserts (e.g. CNMG 120408, inch CNMG 432).
How the code reads
Holder PCLNR 2020K12: P — lever lock, C — 80° diamond insert, L — 95° approach angle, N — 0° clearance insert, R — right hand, 20 × 20 — shank section, K — 125 mm long, 12 — insert size. It takes CNMG 1204.. inserts, e.g. CNMG 120408.
Boring bar S20R-SCLCR09: S — steel shank, 20 — 20 mm diameter, R — 200 mm long, then as for a holder: S — screw clamp, C — 80° diamond, L — 95°, C — 7° clearance insert, R — right hand, 09 — insert size (CCMT 09T3..).
1. Clamping system
| P | hole clamping (lever) — ISO |
| M | top and hole clamping — ISO |
| C | top clamping, insert without a hole — ISO |
| S | screw clamping through the hole — ISO |
| D, T | double clamp — maker's code |
| W | wedge clamp — maker's code |
| B | hook lever, side — maker's code |
| H | hook lever, top — maker's code |
2. Insert shape
| C | 80° diamond |
| D | 55° diamond |
| V | 35° diamond |
| E | 75° diamond |
| S | square |
| T | triangle |
| W | 80° trigon |
| R | round |
| K | 55° parallelogram |
| H | hexagon |
3. Approach angle κr and holder style
| Letter | κr | Style |
|---|---|---|
| A | 90° | straight shank, side cutting |
| B | 75° | straight shank, side cutting |
| C | 90° | straight shank, end cutting |
| D | 45° | straight shank, side cutting |
| E | 60° | straight shank, side cutting |
| F | 90° | offset shank, end cutting |
| G | 90° | offset shank, side cutting |
| H | 107.5° | offset shank, side cutting |
| J | 93° | offset shank, side cutting |
| K | 75° | offset shank, end cutting |
| L | 95° | 95° on both edges, offset — side and end cutting |
| M | 50° | straight shank, side cutting |
| N | 63° | straight shank, side cutting |
| P | 117.5° | offset shank, side cutting |
| R | 75° | offset shank, side cutting |
| S | 45° | offset shank, side cutting |
| T | 60° | offset shank, side cutting |
| U | 93° | offset shank, end cutting |
| V | 72.5° | straight shank, side cutting |
| W | 60° | offset shank, end cutting |
| Y | 85° | offset shank, end cutting |
Boring bars also have style Q — κr 107.5° (ISO 5609-6); external holders have no Q in the standard.
The most common: L (95°) — turning and facing with one holder; J (93°) — profiling with plunging; S/D (45°) — chamfers and faces; V (72.5°) — profiles with a 35° insert.
4. Insert clearance
| N | 0° |
| B | 5° |
| C | 7° |
| P | 11° |
| D | 15° |
| E | 20° |
5. Hand
| R | right hand |
| L | left hand |
| N | neutral |
Shank: two pairs of digits — height and width in mm (2020 = 20 × 20). The last digits are the insert size, as in the insert code.
Holder or bar length
| A | 32 mm | M | 150 mm |
| B | 40 mm | N | 160 mm |
| C | 50 mm | P | 170 mm |
| D | 60 mm | Q | 180 mm |
| E | 70 mm | R | 200 mm |
| F | 80 mm | S | 250 mm |
| G | 90 mm | T | 300 mm |
| H | 100 mm | U | 350 mm |
| J | 110 mm | V | 400 mm |
| K | 125 mm | W | 450 mm |
| L | 140 mm | Y | 500 mm |
Boring bar shank
| S | steel shank |
| A | steel, coolant through |
| C | carbide shank |
| E | carbide, coolant through |
On boring bars R is a right-hand bar using a left-hand insert, and vice versa.
Clamping, shape, approach angle, clearance and hand follow ISO 5608:2012 (tables 1–5); lengths and boring bar shanks follow Ingersoll's "Turning Holder / Boring Bar Nomenclature – ISO"; bar style Q is ISO 5609-6. A trailing Q means a holder with special tolerances (ISO 5608, position 10); makers also add their own letters.
What the insert code itself means is on the ISO 1832 insert designation page.