Differences in Metric and Imperial Reinforcing Bar (Rebar) Grades and Sizes

All Contractors should be intimately familiar with Steel Reinforcing Bar (Rebar) grades and sizes. With materials coming from all over the globe these days, it is ever important to know the comparison between the Imperial and Metric systems for bar grading and sizing. Starting in 1997, CRSI member steel mills have adopted new “soft metric” standards in their grading and sizing. 

The charts below should be used to cross reference imperial grades and sizes with metric grades and sizes. Watch out because if your specs are in metric and your supplier is still using the imperial system, you may wind up with some really huge bar diameters on site. As you can see, the old #4 (1/2″) bars are now being called out as #13, so be very careful here to avoid these kinds of potentially costly mistakes.

Soft Metric Bar Sizes vs. Inch-Pound Bar Sizes:

Metric Bar Sizes Inch-Pound Equivalents


psi* Minimum
Yield Strength
MPa** Minimum
Yield Strength
40 40,000 280 280
50 50,000 350 350
60 60,000 420 420
75 75,000 520 520

* pounds per square inch
** megapascals

For more information, please visit www.crsi.org/rebar


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1 thought on “Differences in Metric and Imperial Reinforcing Bar (Rebar) Grades and Sizes”

  1. Pingback: How To Read Metric Rebar Marks on Steel Reinforcing « EVstudio Architecture, Engineering & Planning | Blog | Denver & Evergreen | Colorado & Texas Architect

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