Каталог Iscar державки и пластины для нарезания резьбы 2022 - страница 82

The anvil should be selected from the table according to the threading standard. The correct anvil depends on the right inclination angle (β) and insert size. The inclination angle (β) is obtained by selecting the thread turning method and finding the helix angle (φ) for single-start threading, or lead angle (φL) for the multi-start threading. The helix angle (φ) and the lead angle (φL) are determined as exact values by using the formula below or as a graph area (see below: Helix (Lead) angle area by using graph, depending on the threading diameter and lead.

Helix angle (φ) calculation by using Lead angle (φ

L) calculation by using the the Single-Start Threading Formula Single-Start Threading Formula

φ=arctan( P ) φ =arctan( Lead )

π×Dpitch L π×Dpitch

Lead= n×P

When: When:

π ≈ 3.142

Usable formulas

Lead (inch)= 1 inch ×No. of starts

TPI

TPI = No. of threading per inch

1 inch = 25.4 mm

Pitch (mm)= 25.4

TPI