Buying Guide

Types of Washers and Nuts

Uses and Materials

Nuts are used to secure a bolt or screw and washers distribute pressure, relieve friction and prevent leaks. Both nuts and washers can be made from an array of metal and nonmetallic materials.

Nut Types

The best way to ensure you have the right nut is to check and see if its classification matches the screw or bolt you are using. 


Learn more about the different types of nuts available in the chart below.

Nut Types
Description Feature/Benefits Recommended For
The Hillman Group - Cap Nuts Acorn Features a pointed top Covers protruding fasteners
cap nuts Cap Features a rounded top Covers protruding fasteners
rod coupling nuts Coupling Long and slender Joins together lengths of threaded rods
hex nuts Hex Available in a wide range of sizes General uses Clamping and joining
Knurled Nuts Knurled Round, textured exterior allows for easy gripping Attaching diffuser shields on electrical fixtures
lock nuts Locking Available in different types Nylon-insert locking nuts feature a nylon interference washer Prevents bolts from loosening under vibration
Machine Screw - Nuts Machine Screw Used with smaller screws Secures and joins machine screws
Hex Nut - Metric - Everbilt - Nuts Serrated Flange Features a built-in washer Combines the qualities of a locking nut and a hex nut
speed nuts Speed Thin and flat Secures fasteners where there is low clearance
square nuts Square Square-shaped General applications
tee nuts T Features three sharp prongs with short barrel lengths Fastens wood, particle board and composite materials to leave a flush surface
Tensilock Nuts Tensilock Features ratchet teeth inside the base Distributes loads during fastening Holds tightly under vibration
wing nuts Wing Features wings that allow you to twist it by hand Easy-on, easy-off fastenings
Washer Types

Most washers have a constant thickness but some, like spring washers, feature an open construction that allows the thickness to vary.


Learn more about the different types of washers available in the chart below.


Bonded

  • Provide a low-profile appearance
  • Used in conjunction with a gasket


Countersunk

  • Available in a number of shapes, including angle, flanged, 90° and more
  • Removes the need to drill a countersunk hole with flat-or oval-head screws


Dock

  • Has a larger outside diameter and thickness
  • Distributes force evenly


Fender

  • Has a large outside diameter
  • Covers large and oddly sized holes


Fiber

  • Made of vulcanized fiber
  • Used in conjunction with an insulating washer or gasket


Finishing

  • Available in brass and stainless steel
  • Provides a finished look with round or flat screw heads


Flat

  • May be regular or high strength
  • General uses Prevents marring of surfaces


Lock

  • Provides spring action
  • May have a high collar
  • Prevents loosening due to vibration


Machinery Bushings

  • May be made of flexible, nonmetallic material
  • Takes up slack between machinery parts


Rubber

  • Made of hard rubber
  • Sealing


SAE

  • Has a small outside diameter
  • Automotive


Spiral Split

  • Often used in conjunction with a flat washer
  • Locking


Spring

  • May be helical or conical
  • Increases elastic properties of a joint


Tension

  • Made of spring steel
  • Eliminates rattles, side play and lost motion in linkages
  • Connects levers and gear shift rods


Tooth Lock

  • Teeth may be internal or external
  • Bites into surface to lock into place
Features

Gaskets. Best used to seal areas where there s a possibility of gas or liquid leakage.


Single-Thread Nuts. Can be used instead of multiple-thread nuts for lighter-duty applications. Requires less torque and reduces the number of parts you’ll need.


Kits. Nuts and washers often available in kits providing large numbers of several different types of each.