Welding Symbols (Part -1)

Welding symbols are a set of information conveyed by the design department to the welding Engineer and the welding operator. It contains all the necessary information viz. welding position, dimensions and geometry of the weld, details of groove/fillet, welding process etc.

A basic weld symbol consists of three parts namely;

  1. Arrow Line
  2. Reference Line
  3. Tail

These are shown in the diagram given below

Arrow Line: Arrow indicates the position of the joint. The arrow points to one side of the joint. This is called the ARROW SIDE and the side other than the arrow side is called the OTHER SIDE.

The arrow side and other side is shown in the diagram given below;

Reference Line: Most of the Details about the weld are given on the reference line such as Shape of the grove or the fillet, Geometry and dimensions of weld etc. In the ISO system a weld on the arrow side is indicated by placing the weld symbol above the solid reference line and a weld on the other side is shown below a dashed line, as shown in the figure given below;

Whereas in AWS system the weld symbol for a weld is placed below the reference line and for a weld on the other side is shown above the line as shown in the figure given below; (NOTE: Dashed line is not used in AWS system).

In the ISO system symbols on the solid line always refer to the arrow side of the joint and symbols on the dashed line indicate a weld on the other side. The dashed line can be drawn either above or below the solid line but as per standard practice, dashed line is placed below the solid reference line.

To bring more clarity about the arrow side and the other side in a fillet joint, please see the diagram given below;

NOTE:  If weld is made on both sides, as in a double fillet weld (or double groove), the dashed line can be omitted since the weld symbol is placed on both sides of the reference line or lines. Please see the diagram given below;

Tail: Third important part of a welding symbol is tail, Tail is used to designate additional information viz. Reference code and (or) welding process to be used. Tail may be omitted if not required.

ELEMENTARY SYMBOL

In addition to the basic parts of a welding symbol i.e. Arrow line, Reference line and the tail certain elementary symbols are provided on the reference line. The elementary symbols may be complemented by Supplementary symbols, Dimensions and Complementary information.

The elementary symbols are given below;

Please watch the video lecture (given below) for a better understanding of the welding symbols:

This is the first part of welding symbol topic, Second part will be uploaded soon. I request you to give your valuable feedback.

23 comments

    1. Dear Mr. Chang,
      Thank you for visiting my website. Your comments are very encouraging. This is the first part of the topic “welding symbols”. Other necessary information will certainly be covered in the second part of this topic (As per your comment), please keep in touch for the updates. You can also watch my you tube videos at wwww.youtube.com/weldingandndt
      regards
      Sandeep Anand

  1. Thanks.
    Will be great if you cover all the ISO standard symbols for various groups and compare with AWS Standard will be useful.

    If you agree the full article can be published by IIW INDIA in its quarterly journal which is sent to over 4000 practising engineers in India.

    1. Dear Mr. Barry,
      Thank you for visiting my website.Your comments are very encouraging. I regularly upload relevant articles on my website, Please stay in touch for the updates. You can also watch my you tube videos at wwww.youtube.com/weldingandndt
      regards
      Sandeep Anand

  2. Dear Sir,
    Really it’s a very valuable efforts you put regarding welding symbols .over and above I request you to indicate the thickness of plates (Materials) .type of joints in case of variable thickness….etc.Batter you publish this artical in IIW journal…. Thank you very much for this artical.

    1. Dear Mr. Yashwant
      Thank you for visiting my website. This is the first part of the topic “welding symbols”. Other necessary information will certainly be covered in the second part of this topic (As per your comment), please keep in touch for the updates. I would like to tell you that I am ready to write for IIW journal.
      Regards
      Sandeep Anand

    1. Dear Mr. Martin,
      Thank you for visiting my website. Your comments are very encouraging. I regularly upload relevant articles on my website, Please stay in touch for the updates. You can also watch my you tube videos at wwww.youtube.com/weldingandndt
      regards
      Sandeep Anand

  3. Dear sir,
    I am farhan sir iwnt to do CSWIP i have one ques. that is it compulsory to do NDT before CSWIP sir what is the procedure plz give me some suggestion for this.

    Thannks & Regards,
    Farhan

  4. Good Evening!
    Sir, could you please send me latest level lll RT & UT study material for study and examination.

  5. Sir,

    Thanks a lot to comparison between ISO &AWS.

    Sir, can you share the list of BS EN standard which is use in welding.

  6. Dear sir ,
    Your articles are really great and you must be appreciated. Sir I am fresher and recently joined welding department as a DET.
    Sir please suggest how can I enhance my knowledge of ASME codes and how codes would be easy to understand for me..
    Sir please suggest ..
    Its very important for a trainee in welding department

  7. ฉันต้องการเรียนรู้สัญลักษ์งานเชื่อมของยุโรป

Leave a Reply

Your email address will not be published. Required fields are marked *