blog post covers the essential information you need to get the C51 license for structural steel contractors

C-51 License: Structural Steel Contractor’s Road Map

Table of Contents

Structural Steel Contractors are highly skilled tradesman that specialize in the fabrication and construction of structural steel used for:

  • High Rise Buildings
  • Bridges
  • Railways
  • Factories and Structures
  • Planes, Vehicles and Ships

This article will provide you with every single detail you need to know about

  • How to get a C-51 license in California
  • Requirements
  • The structural steel contractors exam 
  • Study guides
  • How to fill out the California state license application

What is a Structural Steel Contractor?

Two construction workers on top of steel beams as the sun is setting

A structural steel contractor fabricates and erects structural steel shapes and plates, of any profile, perimeter or cross-section, that are or may be used as structural members for buildings and structures, including the riveting, welding, rigging and metal roofing systems necessary to perform this workCSLB.GOV

The C-51 license is the classification required in the state of California for all persons looking to bid on structural steel projects where the cost of labor and materials exceeds $500.

Duties of a Structural Steel Contractor

A crane hoisting a large steel beam through the air

The C-51 license can cover a variety of different duties and skillsets.

Structural Steel can take on many shapes and is used as the internal support mechanism for buildings and structures but generally, structural steel contractors engage in duties including: 

  • Rebar installation, shaping, and retrofitting
  • Erecting railings, ladders and cat walks
  • Maintaining and repairing various steel products
  • Riveting, rigging and welding
  • Construction blueprint plan evaluation, estimation and cost calculation
  • Design and installation of metal roof system
  • Placing and connecting of steel
  •  Operating cranes and derricks
  • Maintaining personal and job-site safety
  • Field and shop preparation

To get the C-51 license, you will be tested on all aspects of fabrication, shaping, and installation of steel. You must be familiar with all of these disciplines. 

 A structural steel contractor is legally not allowed to bid on a project that falls outside of the spectrum of reinforced steel fabrication and placing.

Steel Subcontractors

A steel beam with screws in it. Appears to be part of a bridge

Structural steel contractors typically work with  General Engineering Contractors, architects or developers.

The C-51 license is typically held by steel contracting firms that engage in large-scale engineering projects.

A General Engineering Contractor oversees that the structural steel subcontractor has executed their duties in adherence to code.

Learn more about the General Engineering Contractor License!

Online Practice Tests and Study Guides


Logo of the CSLB, includes an illustration of a paint brush, cement truck and saw with the letters CSLB above

The Contractors State License Board (CSLB) is the governing body for all contractors in the state of California.

Their responsibility is to protect the consumer public and ensure that anyone charging over $500 for construction services is qualified and registered with the state of California.

The reinforcing steel contractor license is issued to contractors by the CSLB.

The CSLB administers applications, exams, and maintains a database of all active and inactive contractor license numbers which are public domain.

How to get the C-51 License

Structural steel contractors in California must prove a minimum of 4 years journeyman level experience and pass a two-part state exam with the Contractor State License Board.

To qualify for an exam date you must meet the following requirements:

  • Be at least 18 years of age
  • Have a valid Driver's License or USA Issued Identification
  • Have a Social Security or ITIN #
  • Not Currently be on probation or parole

You must also have:

  • 4 Years Journey Level Experience
  • A Qualifying Individual to sign off on your experience
  • A way to prove your experience if the state asks for documentation

What is a Journey level experience?

Man wearing yellow gloves and a blue hard hat , welding a large steel beam

Journeyman level experience means that you have worked unsupervised full time for a structural steel contractor that holds the C-51 license.

  • A journeyman can perform all of the duties associated with his or her trade.

The CSLB will want to see four full-time years over the last ten years. The years do not need to be consecutive, but they do need to be four years in total. 

Signature of a Qualifying Individual

The following people may be used as Qualifying Individuals to sign off on your experience when applying for the C-51 license:

  • Licensed General Contractor
  • C-51 License Holder
  • Former Supervisor (within the last 10 years)
  • Fellow Employee (within the last 10 years)
  • Business Associate
  • Fellow Journeyman
  • Union Representative

Filling out the C-51 License Application

Your Qualifying Individual will also need to provide a brief but detailed description of your knowledge and skillset.

The way this description is written will be critical to whether or not your application is accepted. For example: 

“Rob has worked with steel for a long time” is not descriptive enough.

The CSLB will want to see something more like:

Rob has installed welded wire mesh, pre-tension tendons, fabricated steel reinforcing bars, erected rails, ladders, catwalksread blueprints, estimated for materials and done job site evaluations” etc.

Work experience for the Contractors License

A large yellow crane next to an un finished skyscraper. when applying for the C-51 license for structural steel in california you may be asked to produce documentation supporting your four years journey level experience

You must be prepared to submit documentation supporting the experience you claim to have. The Contractors State License Board gives you a few ways that you can prove your experience.

  • Tax Returns
  • Check Stubs
  • Contracts
  • Material Order Invoices or Receipts

The CSLB  receives thousands of applications per month so there is a good chance they won’t document your experience but if you are one of the applicants that get reviewed you will need to be ready to submit something. 

The CSLB does not accept pictures of projects.

Application Processing, Fees and Criminal History

The time it takes to get your application processed and assigned a test date fluctuates throughout the year.

Typically you can expect:

  • 6-8 Week Application Processing Time
  • 3-4 Week wait for an Exam date

I have seen some situations where applicants got their test date sooner and somewhere they got their test date much later.

The most common reasons your application would get held up are:

  1. Time of year (processing time slows down during the holidays) 
  2. Criminal History 
  3. Proving Experience
  4. Mistakes on your application 

Application costs for the C-51 License

The Current CSLB fees are: 

Can you get a Contractors License with a Felony in California?

A white hand filling out a criminal background check form with a pen and a pair of glasses laying on the side

Having a criminal record in no way stops you from getting a C-51 License. I have personally helped guys with all types of criminal records obtain multiple licenses.

The key is, to be honest on the application, even if the felony or misdemeanor happened years ago and even if it was expunged.

BE 100% HONEST ON THE APPLICATION, because they will see everything anyway when you do fingerprinting.

The CSLB handles criminal records on a case-by-case basis. Remember, their responsibility is to protect the public. In my experience, they are primarily concerned with criminal charges associated with:

  • Fraud
  • Embezzlement 
  • Forgery

In the state of California, you are required to divulge any criminal charges when applying for any state license even if they have been expunged.

You will need to be prepared to submit anything they ask for regarding your criminal history. 

The C-51 License Exam

The exam will be:

  • 115 Questions on Contractor LAW
  • 115 Questions on Reinforcing steel 
  • You will have 3 hours to complete each portion
  • The exam is multiple choice and is taken on a computer
  • Closed Book

The Structural Steel ( C-51 License) Exam is broken up into 5 sections:

1. Planning and Estimation (20%)

  • Reviewing plans and specifications 
  • Conducting site visits 
  • Coordinating with other trades 
  • Estimating equipment and material

2. Job Preparation (15%)

  • Developing drawings 
  • Storing material 
  • Determining placement of material

3. Shop Fabrication (20%)

  • Processing material 
  • Creating holes and slots in material 
  • Cleaning and priming members 
  • Loading and transporting material

4. Field Erection (20%)

  • • Erecting and securing material 
  • Installing beams and trusses 
  • Installing high strength bolts 
  • Finishing joints and connections

5. Safety (25%)

  • Working in elevated areas 
  • Hoisting and rigging 
  • Correcting safety hazards 
  • Operating lift equipment 
  • Using personal protective equipment (PPE)

Recommended Resources

CSLB Test Locations

Currently, there are CSLB testing locations in the following cities:

  • Berkeley
  • Fresno
  • Norwalk
  • San Jose
  • Oxnard
  • Sacramento
  • San Bernardino
  • San Diego

Learn more about Contractor License LAW

Contractor License Exam Prep

Image of a construction worker holding a tool belt and red hard hat

Some things to remember:

  • The questions you will see on the exam may use outdated terms
  • Processes may be completely different from how things are done on the job site
  • You will see questions about things you may have never done before
  • Questions will be presented to you as if you are running a large scale construction business with several employees and jobs happening all at once. 
  • Know all aspects of your trade

I have helped structural steel companies from all over the country get licensed in California. Many are startled by how strict the laws are here. 

Be as prepared as you possibly can. Studying just 10 minutes a day consistently can dramatically increase your chances of passing the test on your first try.

Focus on and study ONLY the information that you need to pass the C-51 License for Structural Steel.

Steel Apprenticeships

A riveting machine that makes steel bolts

If you don’t have the 4 years required journeyman level experience to get a C-51 license, your journey begins here.

Steel is a global multi-billion dollar sector. Generally, someone looking to get into this trade would find a union or apprenticeship program.

For a detailed explanation of this process, check out my article: Apprentice vs Journeyman.

After gaining the necessary 4 years of journeyman level experience, you would then be able to apply for the C-51 contractor's license. 

Blueprint Reading Course

a blue construction print with a yellow pencil and ruler sitting on top

It is critical for structural steel contractors to be able to read construction blueprints or at least be able to recognize lines and symbols.

Construction blueprints communicate important information about how a structure has been built as well as what materials are necessary or have been used for its construction. 

Being comfortable with construction blueprints is an invaluable skill for all tradesmen but is especially important for those looking to get the C-51 license.

See our Free Blueprint Reading Course.

OSHA Certification

featured image for a blog post about OSHA safety laws. Those looking to get the C-51 license for structural steel should strongly consider enrolling into an OSHA training course

Occupation Safety Hazard Association

Statistically, 21% of all work-related fatalities are in construction.

That equals about 1 and 5 worker deaths on average. In the construction industry, the leading cause of worker deaths is reported as falls, struck by an object, electrocution, and caught-in/between.

The steel industry is notoriously dangerous, especially if your workers are not properly trained.

For employment with a steel contractor, it is typically required that you have completed some level of OSHA training.

Learn more about OSHA Training


Getting the C-51 License can be a huge step up in your career if you are looking to start your own company or become an RMO for an existing firm!

The key is to take action and follow these steps from beginning to end. 

If you have found this article helpful feel free to drop a comment below and be sure to check back for updates!