Originally Posted by UG_Passat
Trying to find a good jack pad for my Harbor Freight floor jack.
The ID of the cup is 3.75"
the OD is 4.25"
The slotted ones I have purchased in the past has always cracked right down the slot, (of course, it is a stress concentration area).
Maybe I should just go buy a hockey puck???
If you want to use a puck, cut it in half and secure it to a piece of plywood. Then you can have your gap for the pinch weld without having it crack, as well as having something that will sit inside your jack cup and won't be easily lost. I've had my puck get stuck to the car and then drop and roll away, falls off when you are moving your jack around, etc. Also, no one will grab it for a game of shinny.
If you want an actual jack pad for jacking on hard points, the hockey puck is good, but it is a little bit too hard. I've used my hockey puck a lot on hex head fasteners (subframe mount) and it is crushed and cracked now. At first I had the orange foam practice puck and the black rubber stacked and that worked pretty well, but I think my dog stole the orange puck.
Disposable wood is still the ultimate I think, it can compress slightly and provide more surface area. I have 12x10 PSL or LVL off cuts and then are the ultimate for jack stand pads because they are very strong and do not crack, but still give a little which gives me confidence that they will not slip
I also just got a 3/4 horse stall mat from TSC as a chair mat and the offcuts from that are deffo becoming jack pads. I was thinking about contact cementing them together to get a nice, thick rubber block.