Lock washers, or locking washers, are used to prevent screws or bolts from turning and coming loose due to vibrations. There are a number of different styles, each offering a different level of vibration protection. Some of the most frequently used styles include:
External Tooth Lock Washers
This type of lock washer is commonly used on binding head screws, pan head screws and round head screws, and is designed with teeth on the outside edge of the washer that bites into the screw head for a tight grip. It has greater vibration resistance than split lock washers. Serrated external tooth lock washers have angled teeth and offers an even tighter grip. Standard washers meet DIN 6767 specs and Serrated washers meet DIN 6798 specs.
Internal Tooth Lock Washers
Good for use with small-headed fasteners, such as high-profile fillister and cheese head screws, this internal tooth lock washer is designed with internal teeth that digs into the screw head to resist vibrations and won’t snag objects. It also offers greater vibration resistance than split lock washers. Metric washers meet DIN 6767 specifications.
Internal/External Tooth Washers
This lock washer design offers a combination of both internal and external teeth to give additional gripping power over the external or internal tooth lock washers. They help to maintain a tight hold of bolted joints under vibration.
Split Lock Washers
Offering minimal amount of vibration-resistant protection, the split lock washer is a ring that is split at one point and bent into a helical shape, and when a screw is tightened, the washer is forced into a flat shape, and adds tension to the joint. Inch washers meet ASME B18.21.1. Metric washers meet DIN 127B specs.
There are several additional types of lock washers including: Diamond-Coated Lock Washes, Spring Lock Washers, and Wedge Lock Washers, as well as specialty or custom manufactured lock washers. If you can’t find the steel, stainless steel, black oxide or hot dipped galvanized lock washer needed for your application, please contact us today for a quote. Our knowledgeable staff is here to help!