Deidra C. Merriwether
Senior Vice President and Chief Financial Officer at W.W. Grainger
Thanks D.G. Turning to Slide 8, we cover revenue and margins at the total company level, but I'd like to highlight a few other key points. Our total company SG&A as a percent of sales was 23.7% a 95-basis-point improvement over the prior year's second quarter as we drove leverage from our top line performance. We continue to invest in our strategic initiatives, but remain committed to not adding unnecessary cost to the business. And our resulting EPS in the quarter was $7.19, up 68% versus the second quarter of 2021.
Turning to our High-Touch Solutions segment for the second quarter. We continue to see strong results with daily sales of 22.2% compared to the second quarter of 2021. We saw broad-based double-digit growth across all geographies and over 20% growth in both mid-size and large customers in the U.S. In the U.S. we continues to see strong double-digit volume growth and price realization of around 11% all helping fuel 23.1% daily sales growth. Canadian daily sales were also strong, up 11.1% or 15.5% in local days and local currency. It's been a long journey and we are proud of the traction the Canadian team has gained with their now fifth consecutive quarter of profitability.
For the segment, GP margins finished the quarter at 39.7%, up 275 basis points versus the prior year, driven primarily by lapping of a $63 million pandemic product inventory adjustment in the prior year period. Excluding this inventory adjustment, we achieved gross margin expansion of over 25 basis points as favorable product mix and largely neutral price cost spreads were partially offset by heightened freight costs. As we managed through this highly inflationary period, while there will be quarter-to-quarter fluctuations due to timing, our goal is to remain price competitive while achieving price cost neutrality.
Increased SG&A spend was driven primarily by higher variable compensation expense as well as continued investments in marketing, payroll and benefits to support growth. Even with the increased investment, we delivered 150 basis points of SG&A leverage year-over-year and when combined with strong gross margin recovery, Q2 operating margin of 15.6% was up 425 basis points versus the prior year period. Overall, the performance in our High-Tech Solutions business remains strong as our powerful value proposition continues to resonate with customers.
Looking at market outgrowth on Slide 10. We estimate that the U.S. MRO market, including both volume and price inflation grew between 12.5% and 13.5%, indicating that we achieved roughly a 1,000 basis points of market outgrowth in the quarter. While we know that our advantaged supply chain contributes to our success, we also continue to see strong growth with our strategic investments. We are excited about the returns that we are seeing on these investments, most notably, with our remerchandising and our data-driven marketing programs. Our continued success give us confidence in our ability to consistently achieve 300 basis points to 400 basis points of annual market outgrowth on an ongoing basis and through the cycle.
Moving to our Endless Assortment segment. Reported and daily sales increased 11.4%, up 21.1% on a daily constant currency basis after normalizing for significant impact of the depreciating Japanese yen. In local currency and local days, MonotaRO achieved 21.9% growth and Zoro U.S. daily sales were up 23.2%. The segment growth continues to be driven by new customer acquisition at both Zoro and MonotaRO and enterprise and repeat customer growth at MonotaRO, an impressive quarter of growth across the segment.
Gross margin expanded 100 basis points versus the second quarter 2021, and was primarily driven by freight efficiencies as average order values increased at both Zoro and MonotaRO, as both continue to focus on B2B customers. As planned, segment operating margin declined 25 basis points in the quarter, consistent with the first quarter. This decline was primarily a result of the new DC at MonotaRO coupled with continued investment in technology, marketing and payroll costs to support growth at Zoro.
Despite the increased investment, Zoro operating margins still improved 85 basis points over the second quarter of 2021 on strong GP improvement. As a reminder, the increased cost at MonotaRO will continue for the remainder of 2022 as they transition to their new Inagawa DC. We anticipate that the business will return to more normal operating margins in 2023.
In addition, we also continue to see positive results with our key Endless Assortment operating metrics. On Slide 12, you can see total registered users across MonotaRO and Zoro combined are up 18% over the prior year period. On the right, we show the continued growth of Zoro SKU portfolio. We are targeting about 2 million SKU additions in 2022 and will likely exceed that given our progress after the first 6 months. At the end of the second quarter, we have around 10.2 million active SKUs on the website.
Now looking to the back half of the year. With another very strong quarter and with July total company daily sales of 19% or 21% in constant currency, we are raising our 2022 full-year outlook. While we acknowledge that the broader market conditions remain uncertain, we have not seen a slowdown in demand in our business and continued to hear positive sentiment from our customers further supporting our revised outlook. Our updated outlook for the full year 2022 includes expected daily sales growth between 14.5% and 16.5% and EPS between $27.25 and $28.75, a 41% increase year-over-year at the midpoint.
We've also updated our supplemental guidance in the appendix, which reflects improved segment operating margins and narrow ranges for all other metrics. While it is not typical for us to change our guidance this frequently, our objective is to provide our most up-to-date view with each earnings cycle. Given the strong revenue and profitability performance to-date, we felt it was necessary to update our guidance metric again this quarter.
With that, I will turn it back to D.G. for some closing remarks.
