CNC Machining Services

Gear Hobbing

At a glance

Lifecycle

Prototyping to production

Lead Time

As fast as 12 days

Materials

All available materials

Tolerance

ISO grade 7 to 12

Machines

Fictiv’s manufacturing network includes a range of gear hobbing machines, including:

Mazak i400AG
Hamai N60
Kitamura-3X Vertical CNC

List of Standard Hobbing Modules / Tools

Units: mm
0.06, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.7, 0.75, 0.8, 0.9, 1, 1.25 and 1.5.

Gear Standards

We accept the following gear hobbing standards:

  • US: ANSI
  • US: AGMA
  • China: GB
  • Japan: JIS
  • Germany: DIN
  • UK: BS
  • France: FN
  • Int’l: ISO

Hobbing vs Wire EDM vs Sinker EDM

Hobbing Wire EDM Sinker EDM
Tolerance level ISO grade 7 to 12 ISO grade 7 to 12 ISO grade 7 to 12
Part size Min LxW: 1 x 1 mmMax LxW: 200 x 200 mm Height: up to 300 mm Min LxW: 8 x 8 mm Max LxW: 350 x 350 mm Height: up to 350 mm Min LxW: 0.3 x 0.3 mm Max LxW: 800 x 800 mm Height: up to 500 mm
Top use cases Internal and external gears, internal deep pockets (must be through hole), hole with keyway Internal gears and features which are not through hole, internal feature requiring minimal fillets such as a hexagonal shaped cutout in a part External gears, shafts with gears, worm gears, plastic gears
Materials All available materials All available metal materials All available metal materials
Minimum fillet radius n/a 0.05mm standard 0.01mm premium precision 0.05mm standard 0.01mm premium precision
Lead time As fast is 12 days As fast is 7 days As fast is 7 days
Profiles and tooling Library of hobbing tools or custom tool No tooling required Custom electrode
Production volume Low to high quantities Low quantities only Low quantities only

Design Recommendations

Customers can minimize cost and lead time by selecting a standard hobbing tool. Building a custom hobbing tool requires longer lead times, greater hobbing tool cost and time for pre-production testing. For custom tools, customers must submit a drawing in addition to a 3D model to specify the gear hobbing tool (module), number of teeth, and level of precision required.

Worm gears are made using a combination of hobbing and milling. Bevel gears are made using a combination of 5-axis CNC and hobbing.

For standard gears, please submit a 2D drawing with your model that specifies the following information: module, number of teeth, and the precision level.

For spur gears, please submit a 2D drawing with your model that specifies the following information: module, number of teeth, pressure angle/helical angle, and the precision level.

For profile shifted gears, please submit a 2D drawing with your model that specifies the following information: profile shift coefficient, tooth to tooth composite error, and tooth profile tolerance.

About the Process

Hobbing is a machining process for cutting gear features on both metal and non-metal parts. The gear teeth (or splines) are progressively cut into a cylindrical piece of material by a series of cuts made by a cutting tool called a hob. Hobbing allows you to achieve various gear shapes and sizes such as spur gears, worm gears and bevel gears. Although gear hobbing can be used for prototyping small quantities, this process is best suited for higher volume production.

Our manufacturing partners have various hobbing tools in stock which allow for quick turnaround times.  If a custom gear profile is desired that is not part of our standard hobbing tool library, customers can order custom hobbing tools to be built. If you want to create internal gear features, we offer Electrical Discharge Machining (wire and sinker), as internal gear features cannot be achieved with hobbing.

Visit our CNC Machining Services Page

Gear Hobbing FAQs

What is gear hobbing?

Gear hobbing is a machining process for cutting gear features on both metal and non-metal parts. The gear teeth (or splines) are progressively cut into a cylindrical piece of material by a sequence of cuts made by a tool called a hob. Hobbing allows you to achieve various gear shapes and sizes such as spur gears, worm gears and bevel gears.

What is the difference between gear shaping and gear hobbing?

Gear hobbing is a widely used cutting process with great versatility, often used for creating gears and spurs. Hobs involve a cutter that rotates in sync with the workpiece that is being "hobbed."

Gear shaping is a cutting method that uses reciprocating action of the cutter to create the gear teeth in the blank . Shapers may cut one tooth at a time, whereas others make multiple passes to cut teeth with a rotating cutter.

Only shapers have the ability to cut internal gear teeth, whereas hobs can cut external spur and worm gears.

What is indexing in gear cutting?

Indexing in gear cutting is a method where the periphery of a cylindrical workpiece is divided into an equal number of parts with the assistance of an index crank and plate.

There are 4 indexing methods for cutting a gear.

  1. Simple Indexing
  2. Compound Indexing
  3. Direct Indexing
  4. Differential Indexing

How are internal gears made?

When manufacturing an internal gear the usual gear hobbing used in spur gear production cannot be used because of its shape. It is generally made using gear shaping that is equipped with a pinion cutter.

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