6" X 5" Duct Reducer & Increaser Non-Crimped Single Wall Galvanized Sheet Metal ducting Connector for Airflow, Heating, Cooling, & air Ventilation Systems Fittings

This is very well made. Wonderful quality controlThe sizes are exact

True to size, it fit

My duct reducer arrived exactly on time in perfect condition. It's a piece of furnace duct so it's hard to get excited about it, I will say the quality seems excellent, no cheesy rivet job here, good solid construction. It mated with my other parts perfectly and it's working great.I love Amazon, I hit Home Depot first but "nope, don't have it, we can order it for you", no thanx Home Depot, I can order it myself.If you need one, this one works! Btw it was packed very well.

I needed this reducer for my dust collection system that uses an  ONEIDA AIR SYSTEMS Super Dust Deputy Molded Cyclone Only  and the cheap Harbor Freight (Central Machinery) 2HP dust collector.After searching everywhere locally for 6"->5" fitting and having absolutely no luck, I decided to order this one. And, it works... but, not without some effort.First, the flat side fits perfectly onto the top port of the Oneida. So that was easy. But, the ridged side required a sledge hammer and hard surface to pound (for about 5-10 minutes) to flatten it and open it up a bit in order to fit onto the dust-collector port itself. If you chose to modify the port on the DC, you could avoid this pounding on the fitting.Once the pounding was done, though, it fits perfectly snug with no air leaks.

This sheet metal adaptor fit my 5" and 6" ventilation duct work beautifully.

Very easy to work with. I needed this reducer when putting in a new fan in my bathroom. My biggest concern when working with ducting is getting sliced by a razor sharp burr. Found no burrs and was done with the connection in a little over 15 minutes - that includes crawling across the attic.

Good design and quality.Worked nicely on my furnace vent extension.Good, good, good and nice price.

I'll use the same review for both the 10 to 6 and 6 to 4 duct reducer because I had the same problem with both from the same seller, TheSheetMetalKid. It's simple. Regarding the 10 to 6, the picture shows the small end is crimped. The description states the small end is crimped. The product info says the metal is 26 gauge. IN FACT: NEITHER END IS CRIMPED AND IT'S 24 GAUGE.Regarding the 6 to 4, same seller, the picture shows the small end is crimped. The description does not say it is crimped or mention the gauge. This makes me cautious, I use the Amazon question system to ask if the small end is indeed crimped. Amazon answers provides an answer from someone (?) who obviously does not know but assures me in no uncertain terms the small end is crimped.So, I order both reducers. IN FACT: NEITHER END IS CRIMPED AND IT'S 24 GAUGE as well.This is how these pipes work: One end of a pipe is crimped (making the diameter smaller) so that it can be inserted into an uncrimped pipe. In air ductwork, 30 gauge pipe is generally used because it is structurally adequate, light weight and cheaper than heavier metal. Transitions like reducers and elbows are generally 26 gauge because their shapes and functions require a more rigid structure while still being light weight and less costly and adequate to the task. 24 guage is typically found in wood stove connections to chimneys or in dust collection systems and such which are subject to hard use.What can I say. SheetMetalKid seems to be one of the annoying Amazon sellers who is clueless about the products he sells. One star doesn't cover it because...do I return the stuff and source it elsewhere? Do I take an hour and a half out of my workday to go to a sheetmetal shop and get it crimped? Do I use a hand crimper which should be avoided except as a desperate last resort since it deforms the pipe unacceptably?