242 is the blue thread locker. Bolts can be removed with simple hand tools.
262 is the red loctite and is permanent. You often need to heat the parts to get them apart again. A lot of heat is usually required. The product sheet says 482 degrees F to break it down. I never use it on small fasteners, but on bigger bolts, like over 3/8" an impact wrench will usually remove them. Many times I do have to take the torch to them though.