Description
Overview:
The Imperial External Shakeproof Washer, ID: 5/16'', is a steel fastener accessory designed to stop nuts and bolts working loose under vibration and shock. Its external serrations bite into the mating surface to increase friction, helping keep joints tight on plant, power equipment, and garden machinery. Supplied in a 50-pack, this silver-coloured washer suits maintenance teams, workshops, and DIY users who need reliable joint security on repetitive jobs. With an internal diameter of 5/16 inch (approximately 7.94 mm), it fits 5/16 inch bolts, set screws, and studs typically found on compactors, generators, pumps, mowers, and attachments. Use under a nut or bolt head to improve grip without increasing the joint height significantly. Ideal for general mechanical assemblies where periodic vibration is expected.
Key Features:
- Internal diameter: 5/16 inch (approx. 7.94 mm) for standard 5/16 inch fasteners
- External serrations provide positive bite to resist loosening from vibration
- Durable steel construction for dependable clamping performance
- Low-profile design adds security without noticeably increasing stack height
- Useful on brackets, guards, covers, and control panels in machinery
- Helps maintain preload in bolted joints between service intervals
- Versatile choice for site equipment, garden machinery, and workshop repairs
- Supplied as a cost-effective 50-pack for routine maintenance tasks
- Works with nuts or under bolt heads; can be paired with a plain washer when needed
- Simple to fit with standard hand tools
Typical Applications:
Common on vibrating and mobile equipment such as plate compactors, generators, compressors, lawnmowers, tillers, and pumps. Suitable for securing engine shrouds, exhaust brackets, guards, handles, control boxes, and light fixtures. Useful wherever assemblies experience vibration, thermal cycling, or repeated start-stop duty and require added resistance to loosening.
Also known as:
External tooth lock washer, external star washer, serrated lock washer, toothed lock washer, shake‐proof washer, star lock washer (external), external serrated washer.
Alternate Part Numbers:
903-1111, 9031111
Product Specifications
| L&S Part No. | 903 1111 |
|---|---|
| Unit of Sale | 1 |
Reviews
Ask a Question
Compatibility
Customers also bought
Related Products
-
![]()
Assorted Linch Pins Sizes: 1/4" - 7/16" Pack of 20£17.76 £14.80 -
![]()
Imperial 'O' Ring Box Set of Various Sizes (382 pieces)£17.76 £14.80
