Insert decoderCalculate CNC

Decode any ISO 1832 / ANSI turning insert designation (DNMG, CNMG, WNMG and more) and see the shape, angles, size and corner radius drawn to scale.

Reference aid — verify before you cut. Thread data per ASME B1.1 (Unified), ASME B1.8 (Stub Acme) and ISO 965 (metric M profile); charts cite their source in each tool. Formulas and data are checked against published standards, but errors and edge cases are possible — always confirm critical dimensions against the controlling standard or a calibrated gage before machining. No warranty; use at your own risk. Tap the star on a tool to favorite it.

Insert designation

Type the shape code — e.g. DNMG432, CNMG431, WNMG432, VBMT331. The first four letters (shape, clearance, tolerance, type) are enough to draw it; add the inch size digits for true scale. Every position is decoded from the standard — see the key below. Tap a value to copy it.

Insert

Capabilities

Designation key

1 · Shape (nose angle)
R round · S 90° · T 60° · P 108° · H 120° · O 135° · C 80° · D 55° · E 75° · M 86° · V 35° · W 80° · A 85° · B 82° · K 55° · L 90°
2 · Clearance (relief)
N 0° neg · A 3° · B 5° · C 7° · P 11° · D 15° · E 20° · F 25° · G 30° · O other
3 · Tolerance class
A · C · E · F · G · H · J · K · L · M · N · U — IC / thickness / height per ISO 1832
4 · Type (hole · CB=chipbreaker)
A hole · B hole · C hole · F no hole · G hole +CB×2 · H hole +CB · J hole +CB×2 · M hole +CB · N no hole · Q hole · R no hole +CB · T hole +CB · U hole +CB×2 · W hole · X spec
5·6·7 · Inch size
IC = digit/8″ · thickness = digit/16″ · radius = digit/64″

Source: ISO 1832 / ANSI B212.4. The first four letters decode for every insert; the trailing inch digits give size, thickness and corner radius. Metric size & thickness codes are table-driven — only the metric corner radius (last two digits ×0.1 mm) is decoded for now.

copied