15M Rebar: Size, Weight, Diameter & Uses in Canada
Reinforcing steel plays an essential role in modern concrete construction. Concrete is highly effective at resisting compression, while reinforcing bars help provide the tensile reinforcement needed to improve the strength and performance of concrete structures.
15M rebar is one of the standard Canadian metric reinforcing bar sizes used in residential, commercial, industrial, and infrastructure construction.
But what does 15M mean? What is the diameter of 15M rebar? How much does it weigh? What is it used for, and how does it compare with 10M, 20M, and 25M rebar?
This complete guide explains 15M rebar size, weight, diameter, applications, Canadian specifications, and installation considerations.
What Is 15M Rebar?
15M rebar is a Canadian metric-designated reinforcing steel bar used to reinforce concrete.
The 15M designation is part of Canada’s metric reinforcing-bar system. It does not mean that the bar has an exact 15 mm diameter.
A standard 15M reinforcing bar has:
- Nominal diameter: 16.0 mm
- Nominal cross-sectional area: 200 mm²
- Nominal mass: 1.570 kg/m
- Approximate weight: 1.055 lb/ft
Canadian reinforcing-bar reference data lists these nominal properties for 15M rebar.
The actual bar size, steel grade, spacing, bends, laps, and placement requirements should always be determined from the project’s approved structural drawings and specifications.
15M Rebar Size and Weight
Understanding the dimensions and weight of 15M rebar is important when estimating material requirements, transportation, fabrication, and installation.
| Property | 15M Rebar |
| Canadian designation | 15M |
| Nominal diameter | 16.0 mm |
| Nominal cross-sectional area | 200 mm² |
| Nominal mass | 1.570 kg/m |
| Approx. weight | 1.055 lb/ft |
| Canadian standard | CSA G30.18 |
The 15M bar is larger than 10M rebar and smaller than 20M rebar, making it a useful intermediate reinforcing-bar size for many concrete applications.
How Much Does 15M Rebar Weigh?
The nominal mass of 15M rebar is approximately 1.570 kg per metre.
For simple estimating:
- 1 metre: 1.570 kg
- 5 metres: 7.85 kg
- 10 metres: 15.70 kg
- 12 metres: 18.84 kg
- 100 metres: 157 kg
- 500 metres: 785 kg
- 1,000 metres: 1,570 kg
A simple calculation is:
Total rebar weight = Total length × 1.570 kg/m
For example, if a project requires 400 metres of 15M rebar:
400 × 1.570 = 628 kg
Therefore, 400 metres of 15M rebar has a nominal mass of approximately 628 kg.
Final project quantities should be calculated from the reinforcement drawings and bar schedule, including required bends, laps, hooks, cut lengths, and waste.
What Is the Diameter of 15M Rebar?
The nominal diameter of 15M rebar is 16.0 mm.
One common mistake is assuming that the number in the Canadian designation represents the exact bar diameter.
For example:
- 10M = approximately 11.3 mm diameter
- 15M = 16.0 mm diameter
- 20M = approximately 19.5 mm diameter
- 25M = approximately 25.2 mm diameter
Canadian metric reinforcing bars are designated differently from some other rebar systems, so the project specification should always be checked before ordering or substituting reinforcement.
What Is the Cross-Sectional Area of 15M Rebar?
15M rebar has a nominal cross-sectional area of 200 mm².
Cross-sectional area is an important engineering property because reinforcement design is based on the amount and arrangement of steel required within a concrete member.
The required reinforcement is not determined by bar diameter alone. Engineers also consider:
- Structural loads
- Concrete dimensions
- Bar spacing
- Concrete strength
- Steel grade
- Development length
- Lap requirements
- Concrete cover
- Structural detailing
- Applicable building requirements
For that reason, 15M should only be used where it is specified or approved by the project’s structural design.
What Is 15M Rebar Used For?
15M rebar can be used in a wide range of reinforced-concrete applications, depending on the structural design.
Common applications may include:
1. Concrete Slabs
15M rebar can be specified for reinforced concrete slabs where the design requires more reinforcement than smaller bar sizes can provide at the specified spacing.
2. Foundations and Footings
Foundation systems can require reinforcing steel to help resist tensile stresses and control cracking.
15M rebar may be specified for certain footings and foundation elements depending on the structural design.
3. Foundation Walls
15M reinforcement may be incorporated into concrete foundation walls where the engineer’s reinforcement schedule calls for it.
Correct spacing, cover, laps, and positioning are important during installation.
4. Concrete Walls
15M bars can be used in structural or reinforced concrete walls as specified by the structural drawings.
5. Residential Construction
15M rebar can be used in selected residential concrete applications where the structural design requires this bar size.
The correct reinforcement depends on the specific building and engineering requirements.
6. Commercial Buildings
Commercial construction projects can require multiple rebar sizes throughout a building.
15M may be used where its cross-sectional area and size are appropriate for the engineered reinforcement system.
7. Industrial and Infrastructure Projects
Industrial facilities and infrastructure projects often involve reinforced concrete elements with different reinforcement requirements.
15M can form part of these reinforcement systems when specified by the project design.
15M Rebar and CSA G30.18
Canadian reinforcing steel is commonly specified according to CSA G30.18, the Canadian standard for carbon steel bars used for concrete reinforcement.
The standard covers requirements for reinforcing bars, including bar designations and material properties.
It is important to understand that 15M identifies the bar size, not the steel grade.
For example, 21 Rebar lists both 400W and 500W grades among its reinforcing-steel offerings and lists 15M as one of its standard sizes.
Therefore, a construction project might specify 15M reinforcement with a particular grade depending on the structural engineer’s requirements.
Always confirm the required grade from the approved drawings, specifications, and material schedule.
15M Rebar vs. 10M, 20M and 25M
Understanding the differences between Canadian rebar sizes can make material planning easier.
| Rebar Size | Nominal Diameter | Nominal Area | Approx. Weight |
| 10M | 11.3 mm | 100 mm² | 0.785 kg/m |
| 15M | 16.0 mm | 200 mm² | 1.570 kg/m |
| 20M | 19.5 mm | 300 mm² | 2.355 kg/m |
| 25M | 25.2 mm | 500 mm² | 3.925 kg/m |
| 30M | 29.9 mm | 700 mm² | 5.495 kg/m |
| 35M | 35.7 mm | 1,000 mm² | 7.850 kg/m |
These nominal Canadian reinforcing-bar dimensions and masses are documented in Canadian rebar reference data.
Is 15M Rebar Better Than 10M Rebar?
Not necessarily.
The correct rebar size depends on the structural design.
A larger bar can provide a greater cross-sectional area, but simply choosing a larger bar does not automatically make a structure better.
Engineers determine the required reinforcement based on the design conditions, including the amount of steel required, spacing, concrete dimensions, loads, development, and detailing.
Always follow the structural drawings rather than selecting rebar based solely on size.
Is 15M Rebar the Same as #5 Rebar?
15M rebar is often compared with US #5 reinforcing bar because their nominal dimensions are similar.
However, the two systems should not automatically be treated as interchangeable.
15M is a Canadian CSA metric designation with a nominal area of 200 mm² and diameter of 16.0 mm.
If reinforcement substitution is being considered, the structural engineer should review and approve the change. Rebar substitution involves more than simply comparing diameters.
15M Rebar for Residential Construction
Residential construction can involve many different concrete reinforcement requirements.
Depending on the structural design, 15M rebar may be specified for:
- Footings
- Foundation walls
- Concrete slabs
- Retaining structures
- Structural walls
- Other reinforced concrete elements
The reinforcement schedule determines the required bar size, spacing, grade, bends, and laps.
For builders and contractors, accurate rebar supply and installation can help keep concrete work on schedule.
Why Proper 15M Rebar Installation Matters
Correct installation is just as important as selecting the correct reinforcing steel.
15M rebar needs to be installed according to the approved structural drawings and project specifications.
Important installation considerations include:
Bar Placement
Rebar must be positioned according to the reinforcement drawings.
Bar Spacing
Specified spacing must be maintained so the reinforcement is distributed as designed.
Concrete Cover
The required concrete cover must be maintained to protect the reinforcement and meet project requirements.
Laps and Development
Where bars overlap or require development, the required lengths and details should follow the structural drawings.
Tying and Support
Reinforcing steel should be properly supported and tied so it remains in the required position during concrete placement.
Coordination
Rebar installation needs to be coordinated with formwork, embeds, sleeves, mechanical systems, electrical systems, and concrete placement.
Professional rebar installation helps reduce placement errors and keeps reinforcement work aligned with the construction schedule.
15M Rebar Supply in British Columbia
For contractors, builders, developers, and construction companies in Surrey and throughout British Columbia, having a reliable reinforcement supplier can simplify project planning.
21 Rebar supplies reinforcing steel for residential, commercial, industrial, and infrastructure construction and lists 10M, 15M, 20M, 25M, 30M, and 35M among its standard reinforcing-steel sizes.
The company also offers bulk and custom orders and serves communities across the Lower Mainland, including Surrey, Delta, Richmond, New Westminster, Burnaby, Port Coquitlam, Langley, and Abbotsford.
This makes 15M rebar suitable for inclusion in larger project supply packages alongside other required reinforcing-bar sizes.
15M Rebar Fabrication
Rebar does not always arrive at a job site as straight, unmodified bars.
Depending on the project, reinforcement may need to be:
- Cut to length
- Bent to specific shapes
- Bundled
- Labelled
- Fabricated according to bar lists
- Prepared for delivery
- Coordinated with installation requirements
21 Rebar provides custom rebar fabrication, including cutting, bending, assembly, project-specific bundling and labeling, and delivery coordination.
Having reinforcement fabricated according to project drawings can help contractors reduce on-site preparation and improve installation efficiency.
How to Calculate 15M Rebar Weight
For preliminary estimating, use the nominal mass of 1.570 kg/m.
Formula
15M rebar weight = Total length × 1.570 kg/m
Example
Suppose a project requires:
750 metres of 15M rebar
Calculation:
750 × 1.570 = 1,177.5 kg
The nominal weight is therefore approximately 1,177.5 kg, or 1.18 tonnes.
This is a basic estimating calculation. Actual purchasing quantities should be based on the project’s bar schedule and include the required cut lengths, bends, laps, hooks, and other fabrication requirements.
15M Rebar Frequently Asked Questions
What is 15M rebar?
15M rebar is a Canadian metric-designated reinforcing steel bar used to reinforce concrete. It has a nominal diameter of 16.0 mm and a nominal cross-sectional area of 200 mm².
What is the diameter of 15M rebar?
The nominal diameter of 15M rebar is 16.0 mm.
How much does 15M rebar weigh per metre?
15M rebar has a nominal mass of approximately 1.570 kg per metre.
What is the cross-sectional area of 15M rebar?
The nominal cross-sectional area of 15M rebar is 200 mm².
Is 15M rebar 15 mm?
No. The Canadian 15M designation corresponds to a nominal diameter of 16.0 mm. The “15M” designation should not be interpreted as an exact 15 mm diameter.
What grade is 15M rebar?
15M describes the size of the reinforcing bar. The steel grade is a separate specification and should be confirmed from the project drawings and material requirements.
21 Rebar lists both 400W and 500W reinforcing-steel grades.
Is 15M rebar suitable for foundations?
15M rebar can be used in foundation reinforcement when it is specified by the structural design. The engineer determines the appropriate size, grade, spacing, cover, laps, and other reinforcement details.
Can 15M rebar be used in concrete slabs?
Yes, 15M rebar may be specified for reinforced concrete slabs depending on the structural design and reinforcement requirements.
Is 15M the same as #5 rebar?
15M and US #5 rebar have similar dimensions, but they belong to different designation systems. They should not be substituted without appropriate engineering review and approval.
Where can I buy or get 15M rebar in BC?
21 Rebar supplies reinforcing steel and provides fabrication and installation services throughout Surrey and British Columbia. Its product range includes 15M and other standard Canadian reinforcing-bar sizes.
Get 15M Rebar Supply and Installation in BC
Choosing the correct reinforcing steel is an important part of successful concrete construction.
From 15M rebar supply and fabrication to professional installation, every stage needs to be coordinated with the structural drawings, project schedule, and site requirements.
21 Rebar Ltd. supports residential, commercial, industrial, and infrastructure projects throughout Surrey and British Columbia with reinforcing-steel supply, fabrication, and installation services.
Whether your project requires 15M rebar alone or a combination of multiple reinforcing-bar sizes, 21 Rebar can help coordinate the reinforcement requirements for your project.
Request a Rebar Quote
Planning a construction project in Surrey or elsewhere in British Columbia?
Contact 21 Rebar to discuss your:
- Rebar requirements
- Project drawings
- Bar sizes and grades
- Fabrication requirements
- Delivery schedule
- Installation scope
21 Rebar Ltd.
Surrey, BC, Canada
Phone: 604-618-9821
Email: 21rebarltd@gmail.com
Strength beneath every structure.