Simboli GD&T ISO 1101: caratteristiche geometriche e riquadro di tolleranza

Le caratteristiche geometriche che un riquadro di tolleranza può controllare, con i loro simboli, il gruppo a cui appartengono e se serve un riferimento.

ISO 1101:2017, clause 5, Table 2 'Symbols for geometrical characteristics' (characteristic, specification group, datum needed, subclause). datum: 'none' = 'no' in Table 2, 'required' = 'yes', 'optional' = 'no' in one row and 'yes' in another (position; line and surface profile, which have no datum as a form specification and a datum as orientation or location). symbol = MechPilot's Unicode mapping by Unicode character name (Miscellaneous Technical block); the drawn symbol follows the figure in Table 2. nameIt = MechPilot's own translation (UNI EN ISO 1101 Italian terms not seen).

Riquadro di tolleranza

Altezza del riquadro H

2 h — Height of frame H = 2h for type B lettering (H 5, 7, 10, 14, 20, 28, 40 for h 2.5, 3.5, 5, 7, 10, 14, 20). Increase it when an additional tolerance value is inscribed in a lower compartment.

Spessore della linea d

0,1 h — Thickness of line d = h/10 for type B (0.25 to 2 mm in Table 2), the same as the lettering line width.

Diametro del cerchio del riferimento parziale

4 h

Fonte

ISO 7083:1983, clause 5, Table 2 (lettering type B) and 5.2; ISO 1101:2017, clause 5 NOTE refers to ISO 7083 and its own Annex F (not seen) for proportions

Indicatore di riferimento

a capital letter in a square frame, connected by a leader to a datum triangle; the triangle may be filled (solid) or open (blank) — ISO 1101:1983, 8.1 (via IS 8000 (Part 1):1985); in ISO 1101:2017 datums are covered by ISO 5459, not seen

Note del file di dati

• Table 2 lists 15 rows; concentricity and coaxiality share one symbol, giving 14 distinct symbols.
• Additional symbols (combined zone CZ, separate zones SZ, unequal zone UZ, projected zone P, MMR M, LMR L and others) are in ISO 1101:2017 Tables 3 and 4 and are not stored here yet.