Selection of cutting oil for gear hobbing

5 min read

Selection Of Cutting Oil For Gear Hobbing


Dr. Castle our expert on Metal Working oils in India is going to brief you on the process of Gear manufacturing and selection of cutting oils for Gear Hobbing operation.

Different Gears Diagram

Gear Manufacturing

Hardcastle petrofer is a leading manufacturer and supplier of gear hobbing oils in India. Gear hobbing manufacturing is a fairly complex metal cutting process and forms an integral part of many industrial products. Gears and Gear drives are one of the key components of all kinds of vehicles, machine tools, aircraft, and household appliances as well as a broad variety of industrial equipment. Proper understanding of the various Gear manufacturing processes and controlling parameters is essential in order to meet the growing demands for better productivity and quality of gears.

Gear Manu Icon

Gear Manufacturing Process

There are a number of processes related to gear hobbing manufacturing.

Gear manufacturing in India can involve several applications to create splines or the teeth of a gear. Gear hobbing is the most common method for modern gear manufacturing while gear shaping still finds some use.

Gear hobbing is a multipoint machining process calculation in which gear teeth are progressively generated by a series of cuts with a cutting tool known as a hob. Both the hob and the workpiece revolve constantly as the hob is fed across the face width of the gear blank.

Gears Working Diagram
Figure Showing Top View and Front View of Gear

Types of Gears

Spur Gears Image

Spur Gears

Helical Gears Image

Helical Gears

Rack and Pinion Gear Image

Rack and Pinion

Beverl Gears Image

Bevel Gears

Miter Gears Image

Miter Gears

Worm Gear

Worm and Worm Gear

Screw Gears Image

Screw Gears

Internal Gears Image

Internal Gears

Gear Hobbing Picture Diagram

Selection of cutting fluid for Gear Hobbing

Factors influencing Gear Hobbing process.

The cutting tool used for tooth generation is called hob, which is very expensive and ensuring the extended tool life to increase the productivity and better quality gear is very essential requirement.

In the age of economic war of survival it has become essential to consider and evaluate new cutter fluids which can offer better tool life and improve productivity and lower overall cost

While deciding the type of cutting oil in India to choose between water miscible (Soluble types) or neat type for various applications one must consider following factors

Machining Operation Icon
Severity of machining operation
Material Icon
Type of material
Size of components
Timer Icon
Speed of machining operation
Rate Icon
Feed Rate

In summary, as a general guideline it is accepted that low speed and heavy cuts involving considerable force are best served by neat cutting oils with selective EP additives however light cut and high speed operation calls for efficient cooling and hence soluble cutting oils are selected.

For Gear Hobbing which is considered as severe operation where depth of cut or metal removal is relatively large and operating speed is comparatively slow wherein more lubrication rather than cooling is required, as a general guidelines following table helps in selecting or calculating suitable coolant as per the machining operation.

Module Victory Range Types of Base oil
Bigger Gears > M8 Above 35 Cst Ester Based
Medium to Bigger Diameter
Gears - M4 to M 8type
30 Cst Ester Based/ Mineral Base
Smaller Gears - Ml to M3 @15 -20 est GTL / Ester blended / Mineral Base

Most of the gears are of MS and HSS material which are more difficult to machine. Hence to achieve desired tool life and good surface finish and higher productivity neat oil with high level of sulphurised and /or chlorinated EP additive type cutting oils are recommended with the different viscosity levels. Different additive and operating temperatures are highlighted below.

Different TypeOf Additives

EP Addictive Type Graph

Friction Coefficient For Different additives

Temprature Graph

One of the major issues faced during Gear Hobbing operation is heavy smoke/fume generation due to very severe cutting operation which is not operator friendly. This is mainly due to poor lubricity and selection of low flash base cutting oils and an in-sufficient EP additive package.

It is also observed that in few older machines there is always uncontrolled leakage of hydraulic oils which affects the performance of cutting oil thereby reducing the tool life and desired finish. This leads to increase in operating cost therefore such machines it is advisable to offer a Dual Purpose oil .i.e cutting oil cum Hydraulic oil to avoid cross contamination and reduce the oil consumption.

Gear Icon

Dr. Castle Solution on Gear Machining

Ester Base Oil Product - lsocut E Series by Hardcastle
  • Ester Base oil Products - lsocut E Series
  • Low & High Viscous - Mineral oil with EP additives: HICUT N VG Series HICUT DP Series
GTL Product
  • GTL Based products : lsocut LG Series
  • Multipurpose oil - Machining & Circulating fluids: Megacut Series