"HF now has 6 ton jack stands:"
I have old sets - they are excellent : strong and stable.
I used them to hold/support my 2-ton GMC COE with 18' bed.
On my macadam driveway, I put a 12"x12"x2" wood "pad" under each jack stand.
Harbor Freight has had 6 ton jack stands for years, but just recently added the triangular safety pin. After the ones that didn't secure with just the ratcheting mechanism. See the attached picture. I have a set (non-HF) that doesn't have the safety pin, and they hold well.
You mean asphaltic concrete probably. No one has made a macadam road in many years. But putting pads underneath the legs are a must to keep them from making holes in the asphalt (also known as flexible pavement). I have a couple depressions from the wheels of my floor jack in my asphalt driveway from jacking up the front of my F250 Diesel (heavy motor and front axle.)
