ChromX® – The rebar that refuses to rust
100 years. That’s the product service life of ChromX® 9100 a concrete reinforcing steel that is almost entirely resistant to corrosion. Scientifically engineered, ChromX® uncoated steel achieves its superior properties of corrosion resistance because of the patented steel microstructure that is formed during production. ChromX® can be handled and fabricated like conventional rebar without the risk of damage, repair or inspection issues.
Why CMC ChromX
100-year service life
ChromX® 9100 is engineered to deliver up to a 100-year service life to first repair— helping extend the durability of critical infrastructure.
Built-in corrosion resistance
Its patented steel microstructure provides corrosion protection from within—no coating to damage, inspect, or repair.
Up to 5x more corrosion resistance
Independently tested to offer up to five times the corrosion resistance of conventional steel, performing in marine, de-icing salt, and aggressive soil environments.
High strength efficiency
Available in ASTM A1035 Grades 100 and 120, enabling reduced congestion and optimized structural design.
Lower life-cycle costs
Superior durability means less maintenance, fewer repairs, and long-term cost savings for owners and agencies.
ChromX Construction Segments
ChromX® is used to build some of the world’s most innovative construction projects. For over 20 years, this revolutionary steel product has been specified in public infrastructure projects and in private development projects throughout the U.S., Canada, Mexico and the Middle East.
It is specially formulated and designed for use as concrete reinforcement in commercial, industrial, utilities, waterways, transportation and other reinforced concrete applications, including:
Commercial buildings, high-rise structures, slabs, beams, columns
Buildings constructed with ChromX® rebar are built to stand the test of time with
many benefits during construction.
• Reduced project cost and lead time
• Reduced rebar congestion and improved constructability
• Save up to 50% in steel weight
• Save up to 60% in labor cost
• Sustainability by doing more with less
(all ChromX® products are made from recycled scrap metal)
High rise buildings: ChromX® steel provides an innovative solution for a variety of structures. Designers can take advantage of ChromX®’s high-strength qualities, using it in foundations, shear walls and columns in high rise construction. Using ChromX® Grade 100 eases congestion, requires less steel and results in overall construction cost savings.
Parking structures: The corrosion resistant properties of ChromX® 4100 provide longer service life for parking structures and result in equal cost to competitive corrosion resistant grade 60 coated rebar products.
Exposed balconies on multi-family housing: The combination of ChromX®’s corrosion resistance along with its high-strength capabilities make it ideal for use in exposed balconies, resulting in extended service life
and safety.
To order ChromX® start a conversation with a CMC representative today.
Decks, girders, columns, abutments
A bridge’s service life (the time from project completion to the first repair) depends on the corrosion resistance of the reinforcing steel inside the concrete. Corrosion begins when the chloride concentration at the steel’s surface reaches the critical chloride threshold (CT) value of that steel. The corrosion continues at the corrosion rate of the steel, eventually causing cracking and spalling of the concrete and deterioration of the structure.
Advantages of designing with ChromX® for a variety of bridge components:
- Decks and abutments: ChromX® fortification against corrosion will provide lon-ger-lasting vehicular load support and assist in distributing these loads more effectively to the steel superstructure.
- Girders: Corrosion resistance ChromX® bar provides more overall strength and deck support at all vulnerability zones.
- Piles/Columns: Using ChromX® to support a substructure footing (either above or below ground) ensures a longer life, higher corrosion resistance and a safer compression/tension ratio.
To order ChromX® start a conversation with a CMC representative today.
Basements, buoyancy rafts, caissons, cylinders, drilled shaft, pile
ChromX® products perform especially well in subterranean geotechnical construction applications. Using ChromX® in deep foundation applications can reduce the depth of concrete mat foundations, resulting in reduced usage of concrete and steel, and reduced labor costs associated with excavation.
Deep foundation applications include:
- Basement foundations
- Buoyancy rafts (hollow box foundations)
- Caissons foundations
- Cylinders
- Drilled shaft foundations
- Pile foundations
To order ChromX® start a conversation with a CMC representative today
Dowel bars and tie bars
The uncoated, corrosion resistance of ChromX® dowels and tie bars extends pavement life and offers reduced life cycle costs in both new and rehabilitated pavement projects.
Smooth round dowels bars, generally 1”, 1 ¼” or 1 ½” in diameter by 18” long at 12” spacing across transverse joints, serve as load transfer devices in plain jointed concrete pavement to bridge vehicle loads across adjacent slabs. Tie bars are deformed steel bars that connect adjacent lanes together.
ChromX® pavement dowels and ties provide more than 100 years of service life, avoiding the costs associated with maintenance and repair and the related disruption in traffic flow.
ChromX® dowel bars can be fabricated from ChromX® smooth rounds. In the field, ChromX® dowels and ties can be handled just like standard uncoated dowel bars. No special equipment is needed for placement.
The high strength benefits of ChromX® also allow for efficiencies in design and the potential of reducing the amount of materials required. This results in upfront cost savings in addition to service life longevity.
ChromX® dowel bars can be fabricated from ChromX® smooth rounds. In the field, ChromX® dowels and ties can be handled just like standard uncoated dowel bars. No special equipment is needed for placement.
To order ChromX® start a conversation with a CMC representative today.
Seawalls, retaining walls, docks, fenders, piers, canals and waterways, ports, marinas, permeable pile groins and jetties
Marine structures are often exposed to highly corrosive environments, making them ideal for the use of ChromX® rebar.
Different areas of the same marine structure may have different corrosion protection requirements. The full ChromX® product line allows designers and engineers to select the product that best fits the application.
Atmospheric zone. A marine atmosphere is very corrosive due to chloride exposure from salt spray, salt fog and salt mist. For atmospheric pier members in marine environments designer should consider using ChromX® 9100
or 4100 depending on the target service life for the structure.
Splash and tidal zones. The splash and tidal zones are generally severe corrosive environments due to repeated
wet and dry saltwater exposure. In this application we recommend ChromX® 9100’s corrosion protection.
Submerged zone. While less corrosive than the splash zone, designers should still consider ChromX® 9100
or 4100 for the submerged zone.
Embedded zone. There is usually lower corrosion potential in the embedded zone depending on the composition and contents of the soil; therefore, ChromX® 4100 or black bar may be the right choice depending on the service life requirement.
To order ChromX® start a conversation with a CMC representative today.
BUILDING LONG-LASTING REALTIONSHIPS
Build smarter from the start
Product selection and pre-construction planning are critical to project success. Our experienced sales professionals and technical experts collaborate with your structural engineers, DOTs, contractors, and parking consultants early in the design phase to identify the best solution for your project.
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Optimize total project cost
We work alongside your team to develop a comprehensive life-cycle cost analysis tailored to your project goals and budget.
BY EVALUATING BOTH UPFRONT AND LONG-TERM COSTS, WE HELP YOU:
- Maximize durability with corrosion-resistant materials like ChromX® rebar
- Reduce overall steel weight
- Minimize on-site placement time and labor
- Identify opportunities for meaningful cost savings
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Improve constructability and reduce risk
Using advanced 3D concrete and rebar BIM modeling, we assess constructability before construction begins—helping you avoid costly surprises.
WITH THIS APPROACH, YOU CAN:
- Identify and resolve congestion issues early
- Improve overall constructability
- Reduce the risk of delays and rework
- Anticipate design challenges before they impact the schedule
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Lower material costs through smarter sourcing
Our vertically integrated steel supply chain and strong supplier network ensure efficient material selection and procurement.
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Lower life-cycle costs
THIS ALIGNMENT HELPS:
- Streamline purchasing decisions
- Improve material availability
- Deliver measurable cost savings across your project
Below you will find answers to the questions we get most often about ChromX®. More product information is available in the Resource Library on cmc.com, or you can contact your regional sales representative who will be happy to help answer your questions.
What does ChromX® stand for?
ChromX® is a low-carbon, chromium alloy steel bar. ChromX® 9100 and 9120, 4100 and 4120, rebar shall meet the requirements of Table 1 as per ASTM A1035-20.
How long have ChromX® products been on the market?
The initial production of ChromX® steel reinforcing bar was in 2001. It has been a leading corrosion-resistant, high-strength steel in the market since 2002.
Is ChromX® steel proprietary?
ChromX® steels are proprietary but are sold under a general non-proprietary specification. To support the use of innovation by state and federal departments, the FHWA published a new federal rule on September 27, 2019 that gives states more flexibility in the selection of products used in federal-aid highway projects.
There is no other uncoated product like ChromX® on the market today offering the corrosion resistant properties, high strength and ductility along with the benefits derived from these properties. Therefore, state transportation departments can certify that there is no equally suitable alternative.
How is ChromX® produced?
ChromX® is produced with recycled materials through a combination of alloy additions and a controlled manufacturing process. The combination of the steel’s chemical composition and production process develops the unique microstructure of the steel that drives the advantageous product properties. ChromX® steel bars are manufactured by CMC at CMC Steel in Cayce, South Carolina, and by Cascade Steel Rolling Mills, Inc. in McMinnville, Oregon.
Does ChromX® weigh the same as standard rebar?
Yes. ChromX® weighs the same for similar lengths and diameters.
ChromX® 2000, 9000 and 4000 Series are produced in full accordance to ASTM International – ASTM A1035 (2020), Standard Specification for Deformed and Plain, Low-Carbon, Chromium, Steel Bars for Concrete Reinforcement, Grades 100 and 120 types CS, CM, respectively. ChromX® series meet and exceed ASTM A615-20 Grade 100.
What is the alloy content of ChromX®?
ChromX® is a low-carbon, chromium alloy steel bar. ChromX® 9100 and 9120, 4100 and 4120, rebar shall meet the requirements of Table 1 as per ASTM A1035-20.
| Alloy Type | Carbon | Chromium | Manganese | Nitrogen | Phosphorus | Sulfur |
| A1035 CS ChromX 9100 and 9120 | 0.15% | 8.0 - 10.9%(A) | 1.5% | 0.05% | 0.035% | 0.0455% |
A1035 CM ChromX 4100 and 4120 | 0.20% | 4.0 - 7.9% | 1.5% | 0.05% | 0.035% | 0.0455% |
| (A)AASHTO M 344 M/M 334 - 17 has a minimum 9.2% Cr content. | ||||||
How do engineers specify ChromX®?
ChromX® 9000 and 4000 products can be specified as reinforcing bars conforming to ASTM A1035-20 respectively, along with the grade designation (100 or 120). For highways and bridge applications, according to AASHTO, ChromX® 9100 products can be specified as low chromium reinforcing bars conforming to AASHTO M 334 M/M 334 along with the grade designation (100).
How do engineers design with ChromX® Grade 100? Are there guidelines designers can refer to?
Engineers shall comply with applicable building codes by cities, counties and states, ACI 318 and IBC 2009, 2012, 2015 and 2018. In addition, designers shall be guided by the ACI 439-6R-19 and ICC ESR-2107, which provide design guidelines on the use of ASTM A1035 up to 100 ksi yield in structural designs. The AASHTO LRFD Bridge Design Specifications also provides guidance for designing bridges up to 100 ksi yield strength.
Additionally, we offer design guidance and assistance to engineers when they are faced with unique structural challenges. Our experienced sales team can collaborate with your engineers to mitigate construction challenges and improve constructability with cost-competitive, innovative solutions.
Can engineers design with ChromX® in accordance to the International Building Codes (IBC)?
ICC ESR-2107 provides design guidelines on the use of ASTM A1035 up to 100 ksi yield in structural designs in accordance to the Acceptance Criteria ICC AC429, thereby conforming to the requirements of IBC 2009, 2012., 2015 and 2018.
Can engineers design with ChromX® in accordance to the American Concrete Institute (ACI)?
In 2019, the ACI published the ACI 318-19 which includes the design code requirements for using ASTM A1035 Grade 100 in all gravity loads. In addition, in 2019, the ACI published the ACI 439-6R, Design Guide for the Use of ASTM A1035/A1035M Grade 100 Steel Bars for Structural Concrete, which guides engineers to safely design with ASTM A1035/A1035M at a yield strength of 100 ksi.
Can engineers design with ChromX® in accordance to the Canadian
Standards Association (CSA)?
Currently, there are no Canadian specifications and standards that cover the ChromX® products or their use in concrete design. The numerous Canadian projects where that ChromX® has been used have been constructed to ACI, ICC-ES or AASHTO design standards or standards specific to agencies in a province.
Does AASHTO allow the use of ChromX®? What strength does AASHTO allow?
Yes, the American Association of State Highway and Transportation Officials (AASHTO) LRFD Bridge Design Specifications, 9th Edition 2020, allows the use of steel reinforcing bar up to 100 KSI (690 MPa). Therefore, all ChromX® series that are certified in accordance to ASTM A1035/A1035M and/or AASHTO M334 M/M 334 are allowable.
Is there test data available to prove ChromX® 9000 products will last 100 years?
Numerous independent third-party testing studies, such as universities and state DOTs, have found ChromX® 9000 products provide a service life of over 100 years. Given that many of these studies were written prior to our product line expansion, they often mention MMFX2 when referring to the ChromX® 9000 series.
How does one determine the developing length of ChromX® rebar?
When designing per ACI 318-19, the process for determining the development length of ChromX® ASTM A1035/A1035M CS and CM Grade 100 rebar is consistent with conventional reinforcing steel Grade 100 as per sections 24.4.2.3 or 25.4.2.4 using the modification factors of section 25.4.2.5 of the latest ACI 318-19.
When designing per ACI 318-14, ACI 318-11 or ACI 318-08, the ACI 439-6R-19 recommends determining the development length of ChromX® ASTM A1035/A1035M CS and CM Grade 100 rebar to be calculated using the relevant ACI development equation provided it is properly confined. Alternatively, for both confined and unconfined spliced bars, equation recommended in ACI 408R with revised strength reduction factor, Φ of 0.80 instead of 0.82 used by ACI 408R is recommended.
If builders have a rebar congestion issue, can ChromX® help?
Yes. One of the major benefits of ChromX® steel is the high-strength properties and the potential to help reduce rebar congestion. Using Grade 100 or Grade 120 reinforcing steel can reduce rebar requirements from 20 – 40 percent over Grade 60 reinforcing steel.
Is ChromX® more brittle due to its high strength?
ChromX® steel bars have the same minimum ductility as conventional steel bars (Grade 80 and 100) due to its microstructure. There is no compromise between strength and ductility. Each size produced from the heat (batch) of steel, receives a bend test per ASTM and the results are recorded on the certified material test report (MTR). Unlike other conventional high strength steel bars, ChromX® steel bars provide a minimum T/Y ratio of 1.25 vs 1.10 for other steels.
Can ChromX® products exceed the bend requirements of ASTM A615?
Can they be field bent?
Engineers follow the ACI 318-19 and ACI 439.6R (when designing using ACI 318-14, ACI 318-11 or ACI 318-08) on minimum bending diameter requirements. The same applies to conventional black steel. ChromX® rebar can be field bent per ACI 318, which prohibits heat bending and bending bars embedded in concrete. Heat bending is prohibited, because heat can adversely impact the high-strength and the high-corrosion resistant properties of ChromX® steel reinforcing bars.
Can ChromX® be welded?
ACI-439-6R Sec 10.4 restricts welding, but it also refers designers to ASTM A1035 Note 2 that states welding should be approached with caution.
Can ChromX® be threaded?
Yes. ChromX® can be rolled and cut threaded.
Is ChromX® referenced in the U.S. Army Corps of Engineers Guide Specifications?
Yes. ASTM A1035 is referenced in USACE Unified Facilities Guide Specifications, Division 03 – Concrete, Section 03 20 00.00 10, Concrete Reinforcing.
ChromX 2100 is only produced by Cascade Rolling Mills upon inquiry. A minimum order quantity of 300 Tons is required.
Product Overviews
Dowel Overview
ChromX® Product Information Guides
ChromX® Product Guide Specifications (Word) | (PDF)
Supplemental Information and Standards
Building Cold Requirements for Structural Concrete (ACI 318-19)
