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Punte per la maschiatura delle filettature metriche ISO a passo grosso (ISO 2306)

La punta da usare prima di maschiare una filettatura metrica ISO a passo grosso, con il passo della filettatura.

FilettaturaPasso (mm)Punta (mm)
M1.60,351,25
M1.80,351,45
M20,41,6
M2.20,451,75
M2.50,452,05
M30,52,5
M3.50,62,9
M40,73,3
M4.50,753,7
M50,84,2
M615
M716
M81,256,8
M91,257,8
M101,58,5
M111,59,5
M121,7510,2
M14212
M16214
M182,515,5
M202,517,5
M222,519,5
M24321
M27324
M303,526,5
M333,529,5
M36432
M39435
M424,537,5
M454,540,5
M48543
M52547
M565,550,5

ISO 261:1998, Table 2, column 'coarse'; same values in ISO 2306:1972, Table 1. ISO 2306:1972, Table 1, column 'Drill diameter'.

drill diameter ≈ nominal diameter − pitch — ISO 2306:1972, clause 1: the sizes of drills for parallel screw threads of normal length of engagement, the drill diameter being approximately equal to the nominal diameter of the thread minus the pitch

Note del file di dati

  • ISO 2306:1972, clause 0: the hole a drill makes depends on the drill point, the material, the lubricant and the machining conditions; in soft materials the tapped minor diameter can end up smaller than the drill. The table is a guide for conventional (cutting) tapping; it does not apply to thread forming.
  • ISO 2306:1972, clause 1: the drill diameters, except four sizes the standard marks with an asterisk, are selected from the ISO/R 235 twist drill sizes; stocked drill diameters should be used whenever possible (clause 0).

Fonte e verifica

Le citazioni dal file di dati sono in inglese, come sono scritte lì.

Norma
ISO 2306:1972 Drills for use prior to tapping screw threads, clause 3.1 and Table 1 (coarse pitch series); pitches cross-checked with ISO 261:1998 ISO general purpose metric screw threads - General plan, Table 2 (coarse column)
Verifica
primary (è stato visto il testo stesso della norma)
Verificato su
Note sulla verifica
  • pitch and drill were read from ISO 2306:1972 Table 1 (nominal diameter, pitch, minor diameter limits for 5H/6H/7H, drill diameter). Every pitch agrees with the coarse column of ISO 261:1998 Table 2.
  • ISO 2306:1972 Table 1 ends at M56. M60 (pitch 5.5) and M64 (pitch 6) have coarse pitches in ISO 261:1998 Table 2 but no drill in ISO 2306; they are left out (see docs/to-verify.md). Use `rule` for them only with the user's confirmation.
  • ISO 262 (selected sizes for bolts, screws and nuts) was not read; the sizes here are the ones ISO 2306 lists, which include second- and third-choice diameters (M1.8, M2.2, M3.5, M4.5, M7, M9, M11, ...) of ISO 261.
File di dati
library/holes/tap-drills.json

I valori che non è stato possibile verificare sulla norma sono omessi ed elencati in docs/to-verify.md. Controllate la norma stessa prima di affidarvi a un valore in produzione, e segnalate ogni errore su GitHub. to-verify.md · Issue