Konversiounsmethod Tëscht Metric an Unified Inch Threads

E Fuedem ass eng Spiralstruktur déi benotzt gëtt fir Bolzen an Nëss ze verbannen. A verschiddene Länner a Regiounen, verschidde Fuedemnormen gi benotzt. Imperial a metresch sinn déi zwee méi heefeg Standarden.
Am britesche Standard, déi gemeinsam Fuedem Spezifikatioune sinn UNC an UNF. UNC ass d'Ofkierzung vun Unified National Coarse, dat bezitt sech op den vereenegt nationale grober Fuedem; UNF ass d'Ofkierzung vun Unified National Fine, déi op den vereenegt nationale feine Fuedem bezitt. Zum Beispill, Enk 1/4-20 heescht eng vereenegt national grober Fuedem mat engem Terrain vun 20 TPI (thread pro Zoll) an engem Duerchmiesser vun 1/4 Zoll.

Zoll System vereenegt thread gi wäit an Zoll System Länner benotzt. Dës Zort Fuedem ass an dräi Serie opgedeelt: grober thread Serie UNC, fein thread Serie UNF, extra fein thread Serie UNFF, plus a fixed pitch series UN.

Marking method: Thread diameter-number of threads per inch; Series code-accuracy level

Example: Coarse tooth series 3/8-16 UNC-2A

Fine tooth series 3/8-24 UNF-2A

Extra fine tooth series 3/8-32 UNFF-2A

Fixed pitch series 3/8—20 UN—2A

The first digit 3/8 represents the outer diameter of the thread in inches. To convert to the metric unit mm, multiply by 25.4, that is, 3/8×25.4=9.525mm; the second and third digits 16, 24, 32, an 20 are The number of teeth per inch (the number of teeth on a length of 25.4mm); the text codes after the third digit, Enk, Net, UNFF, UN, are the series codes, and the last two digits, 2A K), are the accuracy level.

It is stipulated in the unified thread standard that a nominal size can have different pitches. Zum Beispill, 1/2 has 13 teeth, 16 teeth, 20 teeth, an 32 teeth. The standard stipulates that 13 teeth are coarse teeth and 20 teeth are fine teeth. 28 teeth are ultra-fine teeth; 16 teeth and 32 Zänn ginn allebéid konstante Pitch genannt, dat ass net anescht wéi grober Zänn a fein Zänn.