At the Electronics segment, approximately two-thirds of the 63% year-on-year revenue increase in the fourth quarter reflected organic growth with continued broad-based geographical recovery, including increased demand for relays in solar and electric vehicle applications.
At the Engraving segment, revenue increased approximately 16% year-on-year, reflecting a favorable geographic mix, project timing and increased soft trim product demand.
Total Company backlog realizable in under one year increased 19% sequentially in fourth quarter fiscal 2021, with strength in Electronics, Specialty Solutions and Engineering Technologies.
On a consolidated basis, we reported an adjusted operating margin of 12% in fiscal 2021, representing a 90 basis point increase year-on-year, with our fourth quarter margin of 13.3%, the highest quarterly margin Standex has ever reported.
In the first quarter of fiscal 2022, we expect a slight decrease in revenue, but a similar operating margin compared to fourth quarter fiscal 2021.
Revenue increased $28 million or 62.7% year-on-year, reflecting a 42.2% organic growth rate or an approximate $19 million increase.
The Renco acquisition contributed approximately $7.3 million in revenue and continues to be a highly complementary fit with our magnetics portfolio.
Our Electronics operating margin increased to 21.6% compared to 13.1% in the year ago quarter, reflecting operating leverage associated with revenue growth and productivity initiatives, partially offset by increased raw material cost.
In particular, NBOs contributed in excess of $15 million in fiscal 2021 compared to our prior estimate of $12 million on our third quarter earnings call.
Our pipeline remains healthy, with total segment backlog realizable under a year increasing approximately $22 million or 23% sequentially in the fourth quarter as we continue to see strong growth in reed switch-based products in magnetics applications.
Revenue increased approximately $5 million or 15.9% year-on-year with operating income growth of approximately $3.1 million or 119% year-on-year, reflecting a favorable geographic mix, timing of projects and increased soft trim product demand.
Operating margin increased to 15.4% compared to 8.1% in the year ago quarter, reflecting the volume growth, combined with segment productivity and our cost initiatives.
Laneway sales at Engraving were approximately $14.8 million, representing a 9% increase sequentially and greater than 50% increase year-on-year, including growth in software tools, laser engraving and tool finishing.
Revenue increased approximately $8 million or 62.7% year-on-year, reflecting positive trends in pharmacy chains, clinical laboratories and academic institutions, primarily attributable to demand for COVID-19 vaccine storage.
Operating income increased 48.7% year-on-year, reflecting the volume increase, balanced with investments to support future growth opportunities and higher freight costs.
Revenue decreased $5.7 million or 21.8% and operating income was $1.1 million lower, representing a 25.6% decrease year-on-year.
On a sequential basis, operating margin increased to 15.1% compared to 6.2% in third quarter, reflecting a continued broad-based sequential end market recovery and favorable mix, complemented by ongoing productivity initiatives.
Specialty Solutions' revenue increased approximately $1.7 million or 7.1% as its end markets, particularly in foodservice and specialty retail, continued to recover.
Operating income decreased approximately $700,000 or 18.7%.
We believe this product is approximately 20% more energy efficient than current gear pump technology with a longer service life.
From a revenue perspective, four of our five segments reported year-on-year growth, led by the Electronics and Scientific segments with total organic growth over 20% as compared to fiscal fourth quarter 2020.
In addition, from a margin standpoint, adjusted operating margin of 13.3% is the highest quarterly margin that Standex has ever reported, reflecting successful leverage on our volume growth, continued buildout our price and productivity actions, as well as the impact of the strategic portfolio actions David highlighted in his comments.
In the fourth quarter, we reported free cash flow of approximately $26 million or 36% year-on-year increase.
In addition, we generated a free cash flow to GAAP net income conversion rate well in excess of 100% in fiscal 2021.
On a consolidated basis, total revenue increased 26.6% year-on-year from $139.4 million to $176.4 million.
Organic growth was 20.5% while Renco contributed approximately 5.2% and FX contributed 3.5% increase to the revenue growth.
On a year-on-year basis, our adjusted operating margin increased 460 basis points to 13.3%, reflecting operating leverage associated with revenue growth, readout of price and productivity actions and profit contribution from Renco, partially offset by the impact of work stoppages in the Specialty Solutions segment.
In addition, our tax rate was 20.7% in the fourth quarter of 2021 compared to 26.7% in the fourth quarter of fiscal 2020.
We expect a tax rate in the 24% range in fiscal 2022 with a slightly higher tax rate in the first quarter.
Adjusted earnings per share were $1.40 in the fourth quarter of 2021 compared to $0.65 a year ago.
We generated free cash flow of $26.4 million in fiscal fourth quarter of '21 compared to free cash flow of $19.5 million a year ago.
In fiscal 2021, we achieved 118% free cash flow to GAAP net income conversion, inclusive of approximately $8.1 million in pension payments made during the year.
Standex had net debt of $63.1 million at the end of June compared to $82.1 million at the end of March, reflecting free cash flow of approximately $26.4 million, partially offset by $5 million of stock repurchases, along with dividends and changes in foreign exchange.
Net debt for the fourth quarter of 2021 consisted primarily of long-term debt of $199.5 million, and cash and cash equivalents were $136.4 million with approximately $92 million held by foreign subs.
Standex's net debt to adjusted EBITDA leverage ratio was approximately 0.57 at the end of the fourth quarter, with a net debt to total capital ratio of 11.1%.
The Company's interest coverage ratio increased sequentially from 11.4 times to 13.1 times at the end of the fourth quarter.
We had approximately $245 million of available liquidity at the end of the fourth quarter and continue to repatriate cash with $6.8 million repatriated during the quarter.
In total, we repatriated approximately $38 million in cash in fiscal 2021, slightly ahead of our initial expectations.
From a capital allocation perspective, we repurchased approximately 50,000 shares for $5 million in the fourth quarter.
In fiscal 2021, we repurchased a total of 267,000 shares at an average price of approximately $79 per share.
There is approximately $22 million remaining on our current repurchase authorization.
We also declared our 228th consecutive quarterly cash dividend on July 22 of $0.24 per share.
Finally, we expect capital expenditures between $25 million and $30 million in fiscal 2022 compared to $21.5 million in fiscal 2020.

Summary:
In the first quarter of fiscal 2022, we expect a slight decrease in revenue, but a similar operating margin compared to fourth quarter fiscal 2021.
On a consolidated basis, total revenue increased 26.6% year-on-year from $139.4 million to $176.4 million.
Adjusted earnings per share were $1.40 in the fourth quarter of 2021 compared to $0.65 a year ago.