Pressing

After the inspection of raw material in laboratory, the accepted material is issued for pressing, also termed as heading on two stage heading machines. The statistical process control technique is used to monitor the machining allowance, diameter and length. The tooling required for pressing are produced in – house under the control of experienced engineers. These tooling control the parameters like roller corner radius / distance, dimple form which do not under go any further process. X Bar / R chart plotting is used to monitor the roller length variation pressed rollers are regularly macro-etched on sampling basis to detect the surface defects.

  
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Soft Tumbling

Pressed rollers are put through tumbling process in order to remove the pressed flash and sharp corners. The tumbling process carried out after pressing is termed as soft tumbling.

  
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Heat Treatment

The heat-treatment gives the required hardness & homogeneity of microstructure to attain maximum strength & durability in compliance with material used. We provide the roller hardness as per the customers’ specifications.

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Cleaning

After heat- treatment to clean the roller tumbling is carried out.

  
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Diameter Grinding

This is a center less grinding process, which is carried out in three passes (rough pass, semi-finish pass & final pass). The final pass is carried out after the datum face grinding. X Bar / R chart plotting is used to monitor the roller outer diameter variation.
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Face Grinding

After the semi-finish pass on the diameter grinding, rollers are Taken to datum face grinding. This is a very important operation to control end face run out & end face radius. This influences quality of roller in final diameter grinding pass. X Bar / R chart plotting is used to monitor the roller end face run-out variation.
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Honing

Honing process is carried out on ground roller's diameter.
Purpose of honing is to :

  • Improve surface finish
  • Improve roundness
  • Generates micro channel for better lubricity
  
  Crowning
Crowning is a process to make the outer surface curved during Honing operation.
Purpose of crowning is :-
  1. Self alignment in the race ways of bearing to allow some little impertuct condition
  2. Better stress distribution
  3. More bearing life

Final Inspection

After precision washing, oiling & before packing the sample rollers from the batch are sent for final audit to check surface roughness, roundness, crowning, lot size variation, End face run out, length and hardness in sophisticated laboratory, according to specified control plan and dock audit procedure required by various customers. The test certificate is then prepared for the customer.
Our sophisticated laboratory is equipped with highly precision world known machines & equipments and is managed by trained & qualified personnel.

Chemical & Metallurgical Laboratory
Visual Inspection Department


Roundness Testing Machine
Surface Roughness Machine