Updraft

Gear tooth contact

Proportion of tooth contact

b′bch′lc

Along the lead, it is the mean contact length bcb_c as a proportion of the effective face width bb'. Up the tooth, it is the mean contact height lcl_c as a proportion of the working depth hh'.

TypeClassAlong the tooth traceAlong the tooth depth

Notes

  • References
    • Former JIS B 1741-1977 Tooth contact of gears (withdrawn)
      This page has not been checked against the standard itself. The values were taken from an extract published in a manufacturer's technical literature and rebuilt into this table.The layout and wording of the table are not those of the source.
  • This is a withdrawn standard, not the current one.Before using these as a design or acceptance criterion, check the current standard or the agreement with your supplier.
  • What each class means, and how contact is measured along the lead and up the tooth depth, is explained behind the i in the table header.
  • Poor tooth contact causes vibration and noise, and shortens the life of the tooth flank.

Related pages

Gears — Gear tooth contact — Gear Reference Tables | Updraft - Mechanical Engineering Calculators