Steel angle sections are one of the most commonly used structural members in industrial buildings, transmission towers, trusses, pipe racks, conveyors, platforms, staircases, and PEB (Pre-Engineered Buildings). When the available member length is insufficient or transportation limitations exist, splice connections are provided to safely transfer axial forces between two angle members.

The drawing shown above illustrates the standard shop welded splice details for both:

Single Angle Sections
Equal Double Angle Sections

These standard details simplify fabrication while ensuring adequate structural performance.

What is an Angle Splice?

A splice is the connection made between two structural members to create one continuous member.

For angle sections, a steel splice plate is welded over the joint so that the load is transferred through the welds and splice plate instead of directly through the angle ends.

The connection is generally designed to transfer:

Axial Tension
Axial Compression
Minor Bending
Shear Forces

Types of Standard Angle Splices

1. Single Angle Splice (Shop Welded)

A single steel angle is connected using one splice plate placed over the angle leg.

Features

Single splice plate
Continuous shop welding
No weld zone maintained near splice center
Suitable for axial members
Economical fabrication

Typical applications include:

Roof Bracing
Vertical Bracing
Pipe Supports
Ladders
Light Steel Frames

2. Equal Double Angle Splice (Shop Welded)

For double angles placed back-to-back, a larger splice plate is used to connect both angle sections.

Advantages

Higher load carrying capacity
Better load distribution
Increased stiffness
Reduced eccentricity
Suitable for heavy industrial structures

Common applications include:

Truss Members
Crane Structures
Transmission Towers
Industrial Pipe Racks
Conveyor Galleries

Components of a Standard Angle Splice

The splice connection consists of the following parts:

Angle Section

The primary structural member carrying the applied load.

Examples include:

ISA 50×50×6
ISA 65×65×6
ISA 75×75×6
ISA 100×100×10
ISA 150×150×16
ISA 200×200×20

Splice Plate

A flat steel plate welded over the splice.

Its dimensions are selected based on:

Angle size
Load
Required weld length
Plate thickness
Fabrication standards

Weld

The splice plate is connected using continuous fillet welds.

Typical weld sizes shown include:

4 mm
6 mm
8 mm
10 mm
12 mm
14 mm

No Weld Zone

The drawing indicates a 25 mm no-weld zone around the splice center.

Purpose:

Reduces heat concentration
Minimizes welding distortion
Prevents excessive residual stresses
Improves fabrication quality

Standard Splice Plate Dimensions

The drawing provides recommended splice plate dimensions based on the angle size.

Typical parameters include:

Lt – Splice plate length
b – Plate width
t1 – Plate thickness
Z1 – Minimum weld size

As the angle size increases:

Plate length increases
Plate width increases
Plate thickness increases
Weld size increases

This ensures the splice develops the required member strength.

Weld Size Recommendations

Typical minimum weld sizes are:

Angle Size	Minimum Weld
Small Angles	4 mm
Medium Angles	6 mm
Heavy Angles	8 mm
Large Industrial Angles	10–14 mm

Actual weld sizes should always be verified by structural design calculations in accordance with the governing design code.

Design Considerations

When designing an angle splice, engineers should verify:

Axial load capacity
Net section strength
Gross section yielding
Weld strength
Plate bending
Block shear
Eccentric loading
Buckling (compression members)
Fatigue (cyclic loading)
Corrosion allowance (if applicable)

Advantages of Shop Welded Splices

✔ Better fabrication quality

✔ Accurate alignment

✔ Reduced erection time

✔ Lower site welding requirements

✔ Improved dimensional accuracy

✔ Consistent weld quality

✔ Faster project execution

Applications

These standard splice details are widely used in:

Pre-Engineered Buildings (PEB)
Industrial Steel Structures
Warehouse Buildings
Power Plants
Cement Plants
Refineries
Petrochemical Plants
Pipe Racks
Conveyor Structures
Roof Trusses
Steel Towers
Mezzanine Floors
Stair Towers
Equipment Supports

Fabrication Guidelines

For best performance:

Clean all steel surfaces before welding.
Maintain proper root alignment.
Follow qualified welding procedures (WPS).
Use certified welders.
Perform dimensional checks before welding.
Inspect welds visually and by NDT if required.
Apply corrosion protection after fabrication.

Inspection Checklist

Before accepting the splice:

Plate dimensions verified
Correct plate thickness
Correct weld size
Continuous welds completed
No cracks
No excessive undercut
Proper alignment maintained
No visible distortion
Weld length as per drawing
Surface cleaned and painted

Relevant Design Codes

Depending on the project location, splice design should comply with:

IS 800:2007 – General Construction in Steel (India)
AWS D1.1 – Structural Welding Code – Steel
AISC 360 – Specification for Structural Steel Buildings
Eurocode 3 (EN 1993) – Design of Steel Structures
AS 4100 – Steel Structures (Australia)
CSA S16 – Design of Steel Structures (Canada)

Best Practices

Avoid placing splices at locations of maximum bending moment where possible.
Use shop welding instead of field welding whenever practical.
Ensure splice plates are centered correctly.
Follow minimum edge distances and weld clearances.
Protect welded joints with primer and finish coatings.
Verify fit-up before final welding to minimize residual stresses.

Conclusion

Standard shop welded splice details for single and equal double angle sections provide a reliable and efficient method for extending structural steel members while maintaining load transfer and structural integrity. By selecting appropriate splice plate dimensions, weld sizes, and following recognized design codes such as IS 800, AISC, AWS, and Eurocode, engineers can ensure safe, durable, and economical steel connections for a wide range of industrial and commercial projects.