What is a gear module?

The size of the teeth in metric gears: pitch diameter divided by the number of teeth. A larger module means bigger teeth.

Do gears need heat treatment?

Most loaded gears are case hardened or induction hardened for wear; lightly loaded gears may be used as machined.

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Gear cutting

Also called: gear hobbing, gear manufacturing, gear shaping, spline cutting, gear job work

Gear cutting makes the teeth of gears, sprockets and splines, usually by hobbing or shaping, and for high accuracy by grinding after hardening. Gear shops need the gear's module, number of teeth, pressure angle and accuracy class to quote.

Quick facts

Main methods: Hobbing, shaping, broaching (internal), grinding
Gear types: Spur, helical, internal, worm, bevel, splines, sprockets
Key data: Module (or DP), teeth, pressure angle, helix angle, face width
Accuracy: Given as a quality class (DIN, AGMA or ISO)
Heat treatment: Often case hardened or induction hardened
Materials: EN353, 20MnCr5, EN19, EN8, C45, bronze for worm wheels

Which method

Hobbing: fast and accurate for external spur and helical gears, splines and sprockets
Shaping: internal gears and gears next to shoulders
Broaching: internal splines and keyways in volume
Grinding: after hardening, for accurate and quiet gears

What to send

Gear drawing with module, number of teeth, pressure angle, helix angle and hand
Accuracy class and any inspection needed
Material and heat treatment (case depth, hardness)
Blank: supplied by you, or made by the shop
Quantity

Need gear cutting done?

Post your requirement free. Workshops that take your kind of work see it and get in touch. You only talk to the ones that fit.

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Related job work

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Materials

Questions

What is a gear module?: The size of the teeth in metric gears: pitch diameter divided by the number of teeth. A larger module means bigger teeth.
Do gears need heat treatment?: Most loaded gears are case hardened or induction hardened for wear; lightly loaded gears may be used as machined.

The figures on this page are typical values for guidance, written by Diemeco from standard engineering practice. They are not a specification: confirm grades and properties with the relevant standard or the supplier's mill test certificate, and tolerances with your workshop. Last checked 8 October 2026.