I like the exposed nut and thread look too. But another option that would be extremely strong and have a cool clean look would be these magna grip rivets, also known as huck rivets. They are widely used in the heavy truck and coach business and the aircraft industry. Ski-doo snowmobiles use them to hold the front frame together. I install lots of them for collision repairs when sledders try to remove trees at 50+ mph. Also just about every UPS or FEDEX panel truck is held together with them. If you know someone who works at a heavy truck collision shop, chances are they would have the heavy duty rivet gun needed to install them for you. Once installed, it will never work loose like a regular nut and bolt!