Loctite 243 Medium Strength Surface Insensitive thread locker features a general purpose, medium strength, blue thread locker with a high oil tolerance. It has a higher temperature range than all the other blue thread lockers at 360F. For fasteners between 1⁄4" to 3⁄4" (6 mm to 19 mm). Parts can be separated using hand tools. Typical applications include Rocker studs, rocker adjustment bolts, bolts on valve and cam covers, oil pans, disc brake calipers, intakes and alternators, and pulley assemblies.