These are not the strongest clamps, but can supply some fairly impressive clamping pressure. I thought it would be fun to see if it could crush an apple. It did it (good view of this in the video, at the end) easily. The arms did deflect outwards under the load but didn’t show any signs of breaking. Here I’m clipping off two of the prongs on a t-nut to make it narrow enough to fit on the 3/4″ arm: After the epoxy had set, I put some petroleum jelly on the end of the nut as lube. This nut will rub against a 1/4″ washer that is in the counterbore in the pad. To assemble, the retainer is glued to the pad and clamped:

Clamps | Woodworking Tools | Screwfix Clamps | Woodworking Tools | Screwfix

A holesaw is used to cut the outside of the pad and a piece of 1/4″ plywood that will be the retainer: This product carries a product lifetime manufacturers warranty covering both faulty materials and faulty workmanship for the expected life of the product as defined by the manufacturer, it does not cover general wear and tear or damage, batteries, blades, bulbs and other consumables. In the unlikely event of a fault the item returned is subject to fair wear & tear and must not have been used beyond the scope of it's design. Credit subject to status and affordability. Terms and conditions apply. Axminster Tool Centre Ltd trading as Axminster Tools is a credit broker and is Authorised and Regulated by the Financial Conduct Authority. Credit is provided by Novuna Personal Finance, a trading style of Mitsubishi HC Capital UK PLC, authorised and regulated by the Financial Conduct Authority. Financial Services Register no. 704348. I have the four prong variety of t-nut. After it is inserted into the arm, I use screws to hold it in place.The clamping screw needs a nut on the end that will not turn. To do this, I flattened the rod slightly for an interference fit for the nut. For extra insurance, I used epoxy as well: