Page 35 - THREADING CATALOG

USER GUIDE

Example for Anvil Selection According to the Following Data
• External right-hand thread.
• Threading profile: ISO standard. THREAD TURNING
• Thread diameters: Major diameter: Ø20 mm, effective diameter: Ø18.376 mm.
• No. of starts: 1.
• Pitch: 2.5 mm.
• Holder: SER 2020 K16.
• Insert: 16ER 2.50 ISO IC908.
• Thread Turning Method: Right-hand threading with right hand holder.

Helix Angle Calculation (φ°) by Formula Helix Angle Area from the Graph
5°4° 3°
3
P 2°
φ=arctan ) 2.5
( π×D
pitch
2
π×18.376 )
( 2.5
φ=arctan lead [mm] 1.5 1°
or 1
φ≈2.5° 0.5
0
When: 0 10 20 diameter [mm]
φ = helix angle 2°<φ≤3° 18.376
Dpitch = 18.376 mm
P = 2.5 mm
π ≈ 3.142

Recommendation for an Inclination Angle (β°) According to the Thread
Turning Method Definition and Threading Standard
• Inclination Angle (β°) for symmetric profile according to the ISO threading standard for right-hand
threading production with a right-hand holder and obtained helix angle (φ).
• Defined inclination angle: β=2.5 for range of helix angle 2°<φ≤3°.

Thread Turning Method
production of right-hand threading production of left-hand threading
with right-hand holder with left-hand holder
LH

or
RH LH
RH

Anvil Selection
Threading helix (lead) angle φ (φ L) φ (φ L)≥5º 4º≤φ (φ L)<5º 3º<φ (φ L)≤4º 2º<φ (φ L)≤3º 1º<φ (φ L)≤2º 0º<φ (φ L)≤1º
Inclination Angle β 4.5º 3.5º 2.5º 1.5º (std) 0.5º

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