With earnings per share of $7.28, our third quarter performance surpasses our previous record of $5.04 set in the second quarter of this year and nearly matches our full year earnings record of $7.42 that we set back in 2018.
Since our founding 56 years ago, sustainability has been at the core of Nucor's business model.
Our use of recycled scrap-based EAF technology enables us to operate at 70% below the current GHG intensity for the global steel industry.
Econiq steel will further advance our leadership position by applying credits from 100% renewable electricity and high-quality carbon offsets to negate any remaining Scope one or two emissions from our steelmaking process.
With coil width of up to 84 inches, a tandem cold mill and initially two galvanizing lines, the new sheet mill will position Nucor to grow its market share in value-added products from automotive, appliance, HVAC, heavy equipment, agricultural, transportation and construction applications.
The mill's product mix will be approximately 2/3 cold rolled and galv.
Our investment in this greenfield sheet mill represents a continuation of Nucor's balanced approach to capital allocation, investing in projects and acquisitions expected to generate returns that substantially exceed our cost of capital, while also continuing to return at least 40% of our net income to stockholders through a combination of dividends and share repurchases.
This facility will have the capacity of 600,000 tons annually.
Our bar mill group is where our steelmaking started over 50 years ago, and it continues to generate very attractive returns on capital.
We are proud to report our third quarter of 2021 earnings of $7.28 per diluted share, establishing a new quarterly earnings record.
This quarter's results also compare favorably with year-ago third quarter earnings of $0.63 per diluted share.
Due to higher-than-expected inventory profit eliminations, third quarter earnings were slightly below our guidance range of $7.30 to $7.40 per diluted share.
Year-to-date earnings of $15.34 per diluted share are more than double 2018's record annual earnings of $7.42 per diluted share.
Our results reflect strong returns from consistent reinvestment in our operations over the years and outstanding execution by our team by significant organic growth investment projects, representing approximately $1 billion in aggregate capital investment, completed start-up and full product commissioning over the 2019 to 2020 period.
During this past quarter, these projects together generated EBITDA exceeding $180 million.
Just two years after beginning operations in September of 2019, the Gallatin, Kentucky hot band galvanizing lines cumulative EBITDA exceeds the project's $200 million investment.
At 72 inches wide, this line is the widest hot rolling galvanizing line in North America and is uniquely positioned to serve value-added markets, such as automotive, solar tubing, grain storage, culverts and cooling towers.
The facility ran at 112% of design capacity in the third quarter of 2021.
This facility also ran at 112% of rated capacity in the third quarter of 2021.
As most of you are aware, two more major capital projects also totaling approximately $1 billion are on schedule to begin start-up during the fourth quarter.
Looking into 2022, our team constructing the $1.7 billion Brandenburg, Kentucky state-of-the-art plate mill is on track for start-up late next year.
Project-to-date capital spending totaled about $570 million.
Located in the middle of the largest U.S. plate-consuming region and able to produce 97% of plate products consumed domestically, this mill positions Nucor to support domestic production of wind towers, while securing a market leadership position in plate.
Cash provided by operating activities for the first nine months of 2021 was approximately $3.6 billion.
Nucor's free cash flow, or cash provided by operations minus capital spending of $1.2 billion, was about $2.4 billion.
For full year 2021, we now estimate capital spending of approximately $1.7 billion.
At the close of the third quarter, our cash, short-term investments and restricted cash holdings totaled $2.3 billion.
This is a decline of about $900 million from the second quarter level.
During the third quarter, Nucor funded significant uses of cash totaling approximately $3.6 billion, including acquisitions of $1.3 billion, capital spending of $505 million, share repurchases of $858 million and cash dividends of $120 million and a net working capital expansion on inventory, receivables, payables and accruals totaling $766 million.
The cash and short-term investments drawdown, plus the receipt of $197 million from the issuance of green bonds tied to the Brandenburg project.
At the close of the third quarter, total long-term debt, including current portion, was approximately $5.6 billion.
Gross debt as a percentage of total capital was approximately 29%, while net debt was about 17% of total capital.
We remain committed to returning capital through cash dividends and share repurchases a minimum of 40% of our net income over time.
For the first nine months of 2021, cash returned to shareholders totaled $2.1 billion.
That represents approximately 47% of Nucor's net income for this period.
The year-to-date capital returns consisted of dividends of $367 million and almost $1.8 billion of share repurchases.
During the third quarter, we repurchased 8.2 million shares at an average cost of approximately $105 per share.
Year-to-date repurchases totaled 20.35 million shares at an average cost of just over $87 per share.
Over the first nine months of 2021, Nucor's shares outstanding have decreased by about 5.5%.
We have paid and increased our regular quarterly dividend every year since dividends were instituted in 1973.
Issued and outstanding shares have been reduced by more than 10%, moving from 318 million shares at the end of 2017 to approximately 286 million shares at the end of the third quarter.
Over that same period, we have grown our steel bar production capacity by about 13% to 9.6 million tons.
We are having a remarkable year in 2021, but it should not be missed that Nucor's ability to generate higher earnings per share is continuing to grow.
In fact, order backlogs at most of our businesses suggest strength well into 2022.
Compared to third quarter, we expect earnings growth at our steel mills and steel products segments.

Summary:
With earnings per share of $7.28, our third quarter performance surpasses our previous record of $5.04 set in the second quarter of this year and nearly matches our full year earnings record of $7.42 that we set back in 2018.
With coil width of up to 84 inches, a tandem cold mill and initially two galvanizing lines, the new sheet mill will position Nucor to grow its market share in value-added products from automotive, appliance, HVAC, heavy equipment, agricultural, transportation and construction applications.
We are proud to report our third quarter of 2021 earnings of $7.28 per diluted share, establishing a new quarterly earnings record.
Over the first nine months of 2021, Nucor's shares outstanding have decreased by about 5.5%.
We are having a remarkable year in 2021, but it should not be missed that Nucor's ability to generate higher earnings per share is continuing to grow.
In fact, order backlogs at most of our businesses suggest strength well into 2022.
Compared to third quarter, we expect earnings growth at our steel mills and steel products segments.