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Two-Piece Clamshell™ Union Support Brackets for 4x4’s, 4x6\'s or 6x6\'s!
The two-piece set for 4x4\'s is 15\" tall, weighs 6.7 pounds per pair, and is code-rated to support 2.5 tons when through-bolting with 1/2\" bolts (or 1.5 tons with 1/2\" lag screws) and using common Southern Pine as the post.
The two-piece set for 6x6\'s comes in your choice of either of two sizes: 15\" tall with holes for 1/2\" screws/bolts; or 18.75\" tall with holes for 5/8\" screws/bolts (weighs over 13 pounds per set!) The brackets for 6x6\'s support up to 4.5 tons with 5/8\" bolts (or 2.5 tons with 1/2\" bolts) when using common Southern Pine as the post.
The two-piece set for 4x6\'s set is 15\" tall and weighs in at 9.6 pounds.
For the 4x4 and 6x6, you can place the Clamshells™ so the holes line up and you can bolt all the through, or flip one over and all the holes are offset for use with lag screws. The holes on the 4x6 are offset for use with lag screws, but we can make them align as a custom order upon request.
We designed our Clamshells™ in consultation with a structural engineer so we can provide the pictured chart with ratings calculated for all sizes and with lags or bolts. We sell two versions of the 6x6. One with holes for 1/2\" and a taller/stronger version with holes for 5/8\" bolts or lags. (The 6x6 shown in the chart is the 5/8\" version -- the 1/2\" version has the numbers of the 4x6 going in the strong axis.) As you can see, the 6x6 version with the holes for 5/8\" bolts/lags is almost twice as strong.
Build your own rugged and heavy duty PostHugger™ Pergola, Double Pergola, or deck and other DIY\'s with our USA made, 1/8\" thick, steel extension brackets! Also great for fixing/reinforcing the build you already have! These are not flimsy/bendable metal. We make them using 1/8\" thick steel - the Clamshell™ weighs between 6.7 and over 13 pounds (depending on the size chosen) - - strong enough to take what you throw at it, but not so heavy where they are hard to work with.
We use 1/8″ steel which is thicker than a Quarter and a Dime stacked on top of each other. Also unlike others who just cut and ship steel right off their table, we take the time to hand debur and wire brush both the inside and outside of every piece.
We are the original designer of the PostHugger™ brackets, which may be copied, but never equaled! :) If you find a PostHugger™ knockoff, give us a chance to meet or beat their price.
BOLTS/LAG SCREWS ARE NOT INCLUDED WITH OUR BRACKETS; you can pick them up at your local hardware store when you pick up your wood.
Made in the USA: All our PostHugger™ Brackets & metal artwork products are Made in America with American-Made Steel!
© 2026 Thermo-Flex Technologies, Inc. - All Designs, Photos, and Text are the Intellectual Property of Shop Owner and are not to be copied without express written permission.
