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Double-helical (herringbone) gear, normal module 1.5, 20 teeth, helix 20° , face 16, Ø6 bore

What are the dimensions of a 20-tooth, 20° double-helical (herringbone) gear? · Modern device · basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance

Also called: herringbone gear, double helical gear, engranaje bihelicoidal (espina de pescado), Pfeilzahnrad

Exact dimensions. True size, with no printing tolerance added.

length
34.93 mm
width
34.93 mm
height
16.0 mm

Notes

  • Normal module 1.5, helix angle 20°: transverse module 1.6, transverse pressure angle 21.17°, pitch Ø31.93, tip Ø34.93, root Ø28.18; addendum 1.5, dedendum 1.88 (normal-module depths).
  • Two opposed 20° helices meet at mid-face (twist 10.45° each way over 8 mm), so the end thrusts cancel.
  • Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

Double-helical (herringbone) gear, normal module 1.5, 20 teeth… size chart

dimensionvalue
normal module1.5
teeth20
helix angle20°
transverse module1.6
pitch Ø31.93 mm
tip Ø34.93 mm
face16 mm
boreØ6

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Henry T. Brown (1868, public domain)Five Hundred and Seven Mechanical Movements — scan on archive.orgwebPublisher's page; dimensions are facts
507movements.comBrown's movement No. 41: figure, his text and an animationwebPublisher's page; dimensions are facts
Xem StudiodrawingwebPublisher's page; dimensions are facts

Free files

★ Free files 1 parts. Xem Studio design: free to use, print and sell things from; not to be republished as files. Xem Studio Design License. index.json

double-helical-gear-mn1-5-20t-beta20-bore6gear, axis Z, z 0..16, a tooth on +X at z = 0STEP · STL
Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.
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Plain text: sheet.txt · JSON: /api/geometry?object=double-helical-gear-mn1-5-20t-beta20-bore6

Double-helical (herringbone) gear, normal module 1.5, 20 teeth, helix 20° , face 16, Ø6 bore, isometric render of a generated part
Render of double-helical-gear-mn1-5-20t-beta20-bore6 from the free STEP; not to scale.

Fits with

Double-helical (herringbone) gears, 20 : 30, helix 20°, isometric render of a generated part
Double-helical (herringbone) gears, 20 : 30, helix 20°5 sizes★ 1 file

Questions

What are the dimensions of a 20-tooth, 20° double-helical (herringbone) gear?

Normal module 1.5, helix angle 20°: transverse module 1.6, transverse pressure angle 21.17°, pitch Ø31.93, tip Ø34.93, root Ø28.18; addendum 1.5, dedendum 1.88 (normal-module depths).