We achieved another quarterly sales record and earnings per share was up 32% in fourth quarter, resulting in full year sales and earnings per share that were both near the high end of our guidance ranges.
Total sales were $773 million, which is up 25% from last year as we compare it against the toughest patch from the pandemic.
In Engine, total sales were up 28% and the increase was again led by our first-fit businesses.
Fourth quarter sales in Off-Road were up 58%, including about 15 points of growth from Exhaust and Emissions.
Fourth quarter sales were up 36% from prior year and innovative products, which make up nearly half the business, grew twice as fast as the non-proprietary counterparts.
In the US, fourth quarter On-Road sales continued to benefit from higher Class 8 truck production and there was also an impact from a strategic choice we made.
If we adjust our current and prior-year sales to exclude these products, the like-for-like growth in the US is about 35% and we are left with a more profitable business that allows us to focus on what we do best, technology-led filtration.
In Engine aftermarket sales were up almost 26%.
In fact, fourth quarter sales of $376 million were the highest ever, beating the record we set last quarter.
Despite that pressure, independent channel sales grew in the high 20% range and fourth-quarter sales in the aftermarket OE channel were up in the low 20% range.
These razor blade products accounted for more than a quarter of total aftermarket sales and they grew in the mid 20% range during fourth quarter.
We launched the brand almost 20 years ago and sales of these products have grown every year since at least 2010.
In Aerospace and Defense fourth quarter sales declined 8%.
One year ago, Engine sales in China were up almost 25%, while the rest of the region suffered through the pandemic.
Fourth quarter Engine sales were up again this year by about 2%.
The Industrial segment also had a solid quarter with total sales growing 19.5%.
Sales in Industrial Filtration Solutions, or IFS, were up more than 23% in fourth quarter, reflecting strong growth in new equipment and replacement parts.
The replacement parts of dust collection are a more optimistic story with fourth quarter sales up nearly 40%.
Fourth quarter sales were up almost 20%, reflecting growth in new equipment and replacement parts.
Sales of Special Applications grew 27% in fourth quarter with strong contributions from both Disk Drive and Venting Solutions.
Fourth quarter sales of venting products grew 50% with almost two-thirds of the increase coming from Asia-Pacific.
Fourth quarter sales of Gas Turbine Systems, or GTS, were down 11%.
Fourth quarter sales grew 25%, operating income was up 36% and earnings per share of $0.66 was 32% above the prior year.
Fourth quarter operating margin was 14.5%, an increase of 110 basis points from the prior year.
Most of the increase was from gross margin, which grew 70 basis points to 34.4%.
Operating expenses at a rate of sales was favorable at 40 basis points driven primarily by volume leverage.
The fourth quarter increase of almost $10 million reflects a couple of factors [Indecipherable] expense, which includes additional incentive compensation and higher benefit costs and a much easier comparison in the prior year.
Moving down the P&L, fourth quarter other income was $5 million.
We directed about $0.25 billion to shareholders in fiscal '21.
We repurchased 1.9% of our outstanding shares for $142 million and we paid dividend of $107 million, including the 5% increase we announced earlier this year.
We are on pace for more than 25 years in a row of annual dividend increases, which is a trend we are extremely proud of.
I also want to highlight the fiscal '21 adjusted cash conversion of 116%.
With that, fiscal '22 sales are expected to grow between 5% and 10% with currency translation being negligible.
Engine is also planned to up between 5% and 10% and Industrial is a bit higher at 6% to 11%.
In terms of operating margin, we expect a full year rate between 14.1% and 14.7%.
This range implies an increase of 10 basis points to 70 basis points from the fiscal '21 adjusted operating margin and we expect the improvement to come from expense leverage.
At today's prices, we expect to pay 8% to 10% more for our raw materials this year and that translates to a gross margin impact of nearly three full points in fiscal '22 margin.
We continue to expect annualized savings of about $8 million, with about $5 million to $6 million landing in fiscal '22.
We are also making incremental investments in our Advance and Accelerate businesses, including another 10% increase in research and development spending.
In terms of other key financial metrics, fiscal '22 interest expense is planned to be about $14 million, other income is projected between $7 million and $11 million and the tax rate is expected between 24% and 26%.
Capital expenditures are planned up in fiscal '22 with a full-year estimate of $100 million to $120 million.
Additionally, we expect to repurchase about 2% of our shares in fiscal '22, keeping with our multi-decade trend and reaffirming our commitment to shareholders.
Based on these forecasts, we plan for a new earnings per share record between $2.50 and $2.66 and implying an increase from last year's adjusted earnings per share of 8% to 15%.
Compared with fiscal '19, fiscal '21 sales are about flat and gross margin is up 90 basis points.
We turned 106 years old this year.
I've been with the Company for 25 years and this team continues to find new ways to impress me.

Summary:
Fourth quarter sales grew 25%, operating income was up 36% and earnings per share of $0.66 was 32% above the prior year.
Based on these forecasts, we plan for a new earnings per share record between $2.50 and $2.66 and implying an increase from last year's adjusted earnings per share of 8% to 15%.