✓ In stock Phosphate-finish wiper nut for M4-0.70 windshield wiper arm stud applications. The integrated washer flange provides the correct bearing surface and seating depth for wiper arm attachment, ensuring the arm seats firmly against the pivot without damaging the pivot housing. Phosphate finish resists corrosion in the moisture-exposed wiper area. Specifications Type: Wiper Nut Thread Size: M4-0.70 Across Flats: 9mm Overall Height: 4.5mm Washer Diameter: 12mm Finish: Phosphate Vehicle Fitment Universal — M4-0.70 windshield wiper arm stud applications across domestic and import vehicles Cross-Reference Numbers Thread Size: M4-0.70 SMS Part#: 15325 What is a wiper nut and how is it different from a standard hex nut? A wiper nut is a specialized fastener designed specifically for windshield wiper arm pivot studs. Unlike a standard hex nut, it has an integrated washer flange that provides the correct bearing surface against the wiper arm boss, and a specific height that positions the arm at the correct depth on the pivot. Using a standard nut can damage the pivot housing or cause the arm to seat incorrectly. Why is this nut phosphate finish instead of zinc? Phosphate coating (also called parkerizing) is a common finish for small automotive fasteners in moisture-exposed locations. It provides corrosion resistance, has a matte appearance that blends with the underhood environment, and unlike zinc, does not change the dimensional tolerances of the nut — important for a precision fit on wiper pivot studs. What tool do I use to install a wiper nut? An M4 wiper nut has a 9mm across-flats dimension. Use a 9mm socket or wrench for installation. Tighten to the torque specification for your vehicle's wiper pivot — overtightening can damage the plastic pivot housing or strip the stud threads. How do I know when a wiper nut needs replacement? Replace the wiper nut if the wiper arm is loose on the pivot, if the nut shows visible corrosion or thread damage, or any time the wiper arm is removed. Wiper nuts are inexpensive insurance against losing a wiper arm during operation. What pack sizes are available? Available in packs of 50, 100, 200, and 300 to suit individual repairs or shop supply needs.
