GUIDE 02 OF 20 · Reading Foundations · beginner

Arrow Side vs Other Side

Arrow side means the side of the joint identified by the arrow. Other side means the opposite side of that same joint—not the far side of the sheet or the upper side of the page.

After this guide, you can:

Identify the physical arrow side even when the view is rotated
Translate above/below reference-line placement into the correct surface
Recognize a true both-sides instruction

Decode the example Test yourself

ANNOTATED PRINTFillet symbol below the line

Under common AWS-style placement, the fillet weld applies to the arrow side of the joint. Moving the same symbol above the line changes it to the other side.

WHY THIS MATTERS ON A REAL PRINT

A correct icon is not yet a correct decision.

A perfectly sized weld on the wrong side is still wrong. Side significance connects a flat drawing convention to a physical surface on the assembly.

DECODE THE EVIDENCE

What each mark tells you—and what it does not.

Use the third column as a stop-check. It prevents a familiar mark from turning into an unsupported assumption.

Visual cue	What it tells you	What you must still verify
Symbol below the line	Arrow-side instruction in the convention used by these lessons	Below does not mean underside of the page or part.
Symbol above the line	Other-side instruction	Identify the opposite surface of the same joint—not the far side of the sheet.
Matching symbols above and below	Welds on both sides of the joint	Dimensions may differ by side; read each placement.

ON-THE-JOB DECISION

The section view is rotated ninety degrees

01 · Situation

A fillet symbol appears below the reference line, but the apparent ‘bottom’ of the part changes between views.

02 · Read

Ignore page direction. Follow the arrow to the joint and identify the surface on the arrow side; below-line placement applies there in the AWS-style convention used here.

03 · Result

The weld stays assigned to the same physical side even when the drawing view rotates.

REPEATABLE READING SEQUENCE

How to read it without guessing

In common AWS-style placement, a weld symbol below the reference line applies to the arrow side; above the line applies to the other side; matching symbols on both sides call for welds on both sides.

Locate the arrow tip on the joint.
Identify the physical surface on the arrow side.
Check whether the weld symbol is below, above, or on both sides of the reference line.
Verify the joint view before assigning the weld to a surface.

Rotate the part mentally if necessary. Side significance follows the joint and arrow, not the page orientation.

DO NOT CONFUSE

Similar-looking instructions, different fabrication decisions

Arrow side

The side of the joint identified by the arrow

DECIDING CHECKWould it remain the arrow side if the paper were rotated? It should.

Other side

The opposite side of that same joint

DECIDING CHECKDo not substitute ‘top’, ‘back’, or ‘far side’ without using the joint view.

Failure checks

Three mistakes that change the instruction

Using page orientation

Arrow side is a property of the joint. Turning the drawing does not change which side the arrow identifies.

Skipping the joint view

The same line placement can look different when the section or elevation view changes. Confirm the physical joint.

Inventing a second weld

A symbol on only one side of the reference line does not automatically specify a weld on the opposite side.

Check your understanding

Arrow Side vs Other Side practice

1/3

Skill: side significance

In a common AWS-style callout, a fillet symbol is below the reference line. Where does the weld apply?

BEFORE YOU RELEASE THE WORK

Five checks for this symbol

This is a drawing-reading checklist, not an acceptance standard. Use it before fabrication, fit-up, inspection, or answering a test question.

01Locate the arrow tip
02Identify both physical surfaces of the joint
03Check symbol placement above/below
04Read dimensions on the correct side
05Confirm the drawing convention

Questions learners ask

Arrow Side vs Other Side FAQ

Does below the line always mean the bottom of the part?

No. In AWS-style placement, below the reference line means arrow side; it does not mean the lower side of the page or part.

How are welds on both sides shown?

For a fillet weld, fillet symbols are placed on both sides of the reference line. Dimensions must still be read in the context in which they are shown.

Do ISO drawings always use the same convention?

No. ISO 2553 supports systems with different reference-line conventions. Confirm the governing standard and drawing convention.

REFERENCE SCOPE

Standards and editorial basis

This guide teaches common AWS-style drawing interpretation. It is educational material, not a substitute for the purchased standard, project specification, code, WPS, or qualified engineering direction.

AWS A2.4:2020Standard Symbols for Welding, Brazing, and Nondestructive Examination ↗Miller Welding BasicsIndependent educational cross-check for common symbol families ↗

Editorial method. Original training diagrams, worked decisions, misconception checks, and questions are written for learning—not copied from a standards table. Production interpretation must still follow the governing documents.

FINISH THIS GUIDE

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Next: Fillet Weld →

Educational practice only. Verify production work against the governing drawing, applicable standard, WPS, and qualified instruction.