A delivery truck pulled into the yard and heavy sighs arose from the installers who went to meet it. It was another load of ductwork, and everybody knew what to expect: lightweight flanges that collapsed during shipment and duct that was more egg-shaped than round. It would be another long afternoon, just trying to force everything back into shape. Only this time when the door rolled open, the guys couldn’t believe their eyes. The round ductwork had kept its shape.

“Look,” one of the workers said. “WonderFlanges. That explains it.”

Ductwork that’s round, coupled with strong, affordable flanges that keep it that way. That’s WonderFlanges in a nutshell.

Manufactured by Indiana-based Midwest Metal Products, one of the nation’s largest producers of rolled structural parts, WonderFlanges are angle rings that bridge the gap between heavy industrial connectors and lightweight formed flanges. Like the lightweight connectors, WonderFlanges are quick and easy to install, company officials say. But unlike many of those formed rings, WonderFlanges are strong enough to hold their shape, even on large sizes of duct.

“We wanted a product that people can use in places where, maybe, a heavy angle ring isn’t necessary, but where it’s still a plus to have a connector with strength,” says Geoff Wendt, company president. “We experimented with several sizes of raw material before we came up with a final product.”

WonderFlanges have been around for a while, appearing on the scene nearly 15 years ago in response to a customer inquiry. But they’ve never been pushed aggressively by Midwest Metal Products, where angle rings are king.

A new focus

“It’s time for that to change,” Wendt says. “We’ve got a great product here and we want more people to know about it. We’re putting a spotlight on the WonderFlange.”

Designed with a collar that slides inside ductwork, WonderFlanges can be either welded or screwed into place, with connections made in a jiffy. The most popular are single-wall, but double-wall and oval varieties are available as well. Most are black iron, but customers purchase stainless steel and aluminum varieties at a steady clip. And for those who want their rings coated, WonderFlanges can be galvanized for an additional charge.

“The biggest thing I like about those things is they are so cotton-pickin’ fast and they are rigid,” says Steve McDaniel, president of US Duct, located in Kernersville, North Carolina. “They are a fast and quick installation.”

US Duct is known for its ductwork, but company officials said they can fabricate just about anything out of metal.

“The thing about WonderFlanges is they’re pain free,” says McDaniel. “You just pick one up and slide it in.”

WonderFlanges offer several advantages over a typical lightweight connector, Midwest Metal says. For starters, they’re rolled, not stamped, meaning the diameters can be adjusted to suit your needs. The flanges are punched with 9/32-inch holes, equally spaced around the ring, but those aren’t for bolts.

“They are pilot holes,” Wendt says. “You offset the holes till you can see metal on the other side. Just stick a Tek screw in there and zip everything up tight. Only takes a second. And your guys in the field aren’t spending time to layout the holes. It’s already done for them.”


McDaniel explains that the flange makes life easier.

“The Tek screws go in easy,” he says. “It was a little confusing at first, because we were thinking the holes had to line up. Then we realized they don’t, and just like that, it all makes sense.”

If a contractor does want to bolt them up, larger holes can be punched. WonderFlanges come ready to install, no pulling split sections apart and fastening them up, just to make them usable. They’re economical, often cheaper than a standard angle ring. And they are strong. Seriously strong.

“It’s a stout connection but it comes at a good price,” says Andres Sisneros of Sisneros Bros., a full-service ductwork manufacturer based in New Mexico. “The guys who are actually installing these, they like that the rings are solid,” he says. “When you put them on the ductwork, it straightens everything out. They are almost like a stiffener, not just an easy connection.”

Sisneros sends ductwork of all sorts all over the country. They know their connectors.

“The (other connectors) are harder to work with. They’re flimsy and usually they come split. So you’ve got to tack-weld them or screw them to make them hard again,” Sisneros says.

The idea for WonderFlanges came up as customers asked about lightweight flanges that would hold their shape during shipment.

“When we started designing WonderFlanges, we knew they had to be affordable, but more than that, they had to be strong and easy to use,” he says. “We actually took several prototype rings to a sheet metal company, about an hour away from us, and had guys there screw rings together, mount them on duct, the whole nine yards. They were really impressed.”

WonderFlanges can be shipped in “Gaylord” boxes, or bundled together on threaded metal rods. There’s no extra reinforcement necessary for shipping.

“The WonderFlange is a complete ring,” Sisneros says. “They’re stout, you can feel the difference. You’re working with a stiffener (or) connection instead of just an easy way for somebody to connect their ductwork.”

Though WonderFlanges are a bit heavier than your typical lightweight connector, over a full duct run, it’s hard to even notice. And the ease of installation makes it worthwhile.

“With ductwork, I prefer to use them over just about anything else,” McDaniel says.

This article and its images were supplied by Midwest Metal Products.