Have a sled-bed (similar to triton) aluminum snowmobile trailer 8.5X14'. It has no tie-down points for securing atv's or SXS other than the outer edges of the trailer, no points in the center of the trailer. Am thinking of installing a couple of 24" sections of e-track down the center of the trailer to secure atv's.
As you know the e-track has holes ever 2" on both sides. Can't believe I need a screw in every hole and don't want to fill the trailer bed full of that many screw holes.
I was thinking of just putting in 6 or 8, 1/4 X 1-1/2" lag screws into the 1/2" ply wood floor.
My question is..........."Will that be plenty to hold two atv's. Will use them to secure the inside straps and use the outer edge of the trailer to secure the outer straps on the atv's.
What'a think?

 

If you only have a 1/2" plywood floor then you'll need bolts, not screws. The 1-1/2" lags give you nothing - 3/4" would do as well. Beyond that, even if you filled every e-track hole with screws a tightly strapped ATV can jerk the e-track loose from the 1/2" floor.

If you do use bolts, then you can use every other screw hole. Better to alternate from one side to another if you choose to skip every other hole. Overall, it's better to use a bolt in every hole on the e-track - while e-track is strong it can still be bent if enough force is applied. You'd be surprised at how much force a 600 pound ATV can put on just tow attachment points if the load starts to bounce.

If it were mine I'd use bolts in every hole on the track. Small price to pay for knowing that the track will hold up.

 

If there is framing down the center, I prefer to use recessed D-Rings, installed with 5/16 self-tapping pan head screws. They are easy to install (use a 3" hole saw 3/8 down and pop out the hole), very strong, and don't stick up when not in use.

A seller randpcarriages on e-bay usually has them. Get the three hole style. (I don't think we are supposed to post links for things for sale).

They also sell metal backing plates, if you can't install them over a frame tube. There are usually listed each, for four, eight or twelve.