All penetrating oils, including WD-40, are about as much solvent as lube. It will soak into the surface of unprotected fiberglass or carbon composites, but I doubt it will cause damage. And bow limbs are painted or coated, not unprotected. Wood core limbs, now they CAN be damaged by any petroleum based product.

But there are plenty of reasons not to let a can of WD-40 into the same room as your bows, guns and fishing reels. Gummy, dirt attracting and very short lubricating life.

Anyway...

I agree with NYH, that pressing the bow and pulling the limb bolts is the proper way to lube them. If you' ve got solid limb butts instead of split, it might even be the ONLY way. (Anybody remember when you could spread a newspaper out on the kitchen table and completely disassemble a bow with no tools more exotic than an allen wrench, screwdriver and a pair of pliers? This is progress??)

But if you' ve got split limb butts, go down to Wally World and get a spray can of white lithium grease. They come with a plastic tube that fits on the nozzle, just like WD-40. Check your owner' s manual to see just how far you can safely back out the limb bolts. Then back the limb bolts out, stick the tube down thru the slot in the limb butts and spray the bolt threads. Run the bolts in and out a few times to work the lube into the threads in the riser and to the end of the bolts. Might even have to spray the grease on them again to get it done good. It ain' t proper, but it works.