Deidra Cheeks Merriwether
Chief Financial Officer and Senior VP at W.W. Grainger
Thanks, DG. Starting with Slide eight, you can see the high-level results for the total company, including strong daily sales growth of 10.1% on a daily constant currency basis. Although year-over-year growth rates decelerated compared to Q1 as inflation cools and as we lap a tougher prior year comparison, daily sales dollars remained strong, and we are on track to deliver a great year.
Total company operating margin was up 190 basis points as expanded gross margins in both segments were further aided by SG&A leverage in the High-Touch Solutions North American segment. In total, we delivered diluted EPS in the quarter of $9.28, which was up 29% versus the second quarter of 2022. Diving into segment-level details. For the second quarter, we continued to see strong results within our High-Touch segment with daily sales up 9.9%, fueled by revenue growth in all geographies.
Although year-over-year growth rates have slowed as we lap prior year price inflation, volume growth remains healthy and was generally in line with our expectations for the quarter. In the U.S., we continue to see positive growth in nearly all customer end segments. However, this does include pockets of softness, including decelerating growth in manufacturing and commercial services. However, given our diversified customer base, this is countered by strong growth in other areas such as government and health care. In Canada, the economy remains stable, and we are seeing strong results with Canadian daily sales up about 7% in local days and local currency.
For this segment, GP margin finished the quarter at 41.7%, up 200 basis points versus the prior year. Product availability levels remained high, resulting in fewer packages and shorter distance shipments in the current year as service returned to near pre-pandemic levels. This one coupled with lower fuel and container rates is driving significant fuel and supply chain tailwinds in the quarter.
Product mix was also favorable primarily due to improved product availability and a higher mix of margin-accretive products and services. Price/cost spread was slightly negative after adjusting for nonrecurring -- a nonrecurring 40 basis point supplier rebate benefit recognized in the quarter. As expected, the favorability captured in 2022 began to unwind in the second quarter. And we expect this to continue for the remainder of the year as we turn towards our long-term neutrality target. At the operating margin line, we saw improvement of 230 basis points year-over-year as the GP favorability fell to the bottom and revenue growth more than offset continued demand generation investments in headcount and marketing.
Overall, this was another strong quarter for the High-Touch North American segment. Looking at market outgrowth on Slide 10. We estimate the U.S. MRO market grew between 4.5% and 5%, indicating that we achieved roughly 525 basis points of outgrowth in the quarter. Although this is a sequential slowdown from Q1, we comped a very strong prior year quarter and performance remains above our annual target to outgrow the market by 400 to 500 basis points through economic cycles. We are well on our way towards achieving that target again in 2023.
Moving to our Endless Assortment segment. Sales increased 4.5% or 10.1% on a daily constant currency basis, which adjusts for the impact of the depreciated Japanese yen. Zoro U.S. was up 2.8%, while MonotaRO achieved 12.6% growth in local days, local currency. At a business level, MonotaRO continues to execute well and is driving solid year-over-year revenue growth as they increase registered users and grow the enterprise customers. At Zoro, while slower growth partially reflects a tougher prior year comparison, we're seeing slowing demand across their customer base. Similar to Q1, noncore B2C business remained a headwind in the quarter and was down in the mid-teens year-over-year. Further, we have seen a slowdown in Zoro's core B2B business, which makes up a majority of Zoro's revenue.
While we are still growing in the high single digits with these core customers, macro-related factors are impacting demand given Zoro's end market mix as well as their tilt to smaller-sized businesses, which seem to be struggling more in this environment. We expect both of these headwinds to persist for the remainder of the year. Stepping back, Zoro has delivered great results over the last two years as we've added SKUs to our assortment, increased registered users and served both core and noncore customers well during the pandemic.
As we plan for our next leg of growth, the new local leadership team is focusing their efforts to drive repeat profitable growth with core B2B customers. This should help propel our results through the cycle as we continue to provide a one-stop endless aisle with easy-to-find products and a no-hassle delivery experience for smaller, less complex businesses in the U.S. From a profitability perspective, gross margin for the segment expanded 50 basis points versus the prior year due to continued freight efficiencies and strong price realization at MonotaRO, which offset unfavorable product mix at Zoro. Operating margins declined slightly year-over-year to 8.6% as gross margin favorability was offset by continued investments in marketing and slower-than-expected top line growth at Zoro.
On Slide 12, we continue to see positive results with our key Endless Assortment operating metrics. On the left-hand side, in line with prior quarter growth, total registered users grew nicely with Zoro and MonotaRO combined up 16% over the prior year. On the right, we also continue to see growth of the Zoro SKU portfolio, which grew by 200,000 SKUs in the second quarter and stands at over 12.2 million in total. Now looking forward to the rest of the year.
Given our strong share gain to date and the continued supportive demand environment, we are raising the midpoint of our full year 2023 outlook by increasing the lower end of our revenue and earnings ranges. Our revised outlook includes daily sales growth of 8.5% to 11% for total company, which is roughly a 75 basis point increase at the midpoint compared to the prior range. High-Touch growth continues to trend slightly higher than expected as we continue to gain share amidst a reasonably steady demand environment.
The strength in High-Touch is offsetting lower-than-expected top line performance with Endless Assortment, primarily due to the softness at Zoro as previously mentioned. Altogether, at the total company level, we are confident in our ability to drive growth in the second half and achieve our updated estimates. Looking specifically at July, we've started the third quarter strong and reported month-to-date sales up over 8%, which is roughly 50 basis points higher on a daily constant currency basis. From a margin perspective, both gross profit margin and operating margin rate expectations remain unchanged from our previous update.
From a seasonality perspective, we expect Q3 margin rates to decline sequentially quarter-over-quarter. As the onetime supplier rebate, we captured this quarter falls off and as price/cost favorability continues to unwind. Couple this with the continued rapid demand generation investments, and we expect total company operating margins to be lower in the back half of the year. However, we're still on track to finish 2023 with full year operating margins at an all-time high.
All in, the resulting revised EPS range has been raised and stands between $35 and $36.75. Supplemental guidance covering cash flow and share repurchase, which have also been raised, can be found in the appendix of the deck. In summary, I look forward to the remainder of 2023 feeling confident in our team's ability to continue to serve our customers well, achieve profitable growth and drive strong results for our shareholders.
With that, I'll turn it back to DG for some closing remarks.