Jump to content
Mechanical Engineering

What are the different Types of allowances in Casting process?



What are the different Types of allowances in Casting process?



Recommended Comments

Types of allowances:

  1. Shrinkage Allowance
  2. Machining Allowance
  3. Draft Allowance
  4. Shake Allowance
  5. Distortion Allowance

The explanation of above types of allowances are as follows..

1.Shrinkage Allowance:

During cooling of the material in Casting process,in all the Three stages,the material is getting shrinking(reducing its dimensions or volume).But ,shrinkage allowance taking place in 1st two stages is called as Liquid Shrinkage.

  • Shrinkage in 3rd -stage is called as Solid shrinkage.
  • Liquid shrinkages are always compensated by providing a riser in casting process.
  • Liquid shrinkages are always specified as “% by Volume”.
  • Out of different metals casted in the industry, “Aluminum(Al) ” is having highest liquid shrinkage which is about 6%.
  • Solid shrinkage is specified as (Percentage/Dimensions).
  • Solid shrinkage is influenced by four factors.

2.Machining Allowance:

The extra dimension provided on the casting and it will be removed by machining after the casting has been completed is called as Machining Allowance.

Detailed explanation of Machining allowance is as follows.

3.Draft Allowance:

Making the vertical surfaces of the pattern into inclined surfaces is called as Draft Allowance.

4.Shake Allowance:

To maintain the required size of the casting,the original size of the pattern has to be reduced by an amount called as Shake Allowance.

5.Distortion Allowance:

To get the vertical legs of U shaped[Distortion Allowance complete].the original pattern has to be bend inverse so that during solidification,the legs are bending outwards and becoming vertical legs.The amount by which the legs are bending Inverse is called as Distortion or Bending allowance.

Link to comment


5 Types of Allowances in Casting Process You Must Know are as follows.

1.Shrinkage Allowance

2.Machining Allowance

3.Draft Allowance

4.Distortion Allowance

5.Shake Allowance.

I have written a brief article on the different types of allowances and if you want to know,just click the below link.





Link to comment
Add a comment...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Join Mechanical Engineering network

    Join us (login) to get full access : Please sign up to connect and participate.

    To download files...please login

  • Create New...