The Different Metric Machine Screw Heads and Their Uses

metic machine screwWhen it comes to keeping things together, engineers, designers, and builders overwhelmingly choose metric machine screws. They’re in everything from kitchen cabinets to deep-space probes. Given the wide variety of things put together with metric machine screws, it’s no surprise that there is such a wide variety of metric screws to choose from. Learn about the different types of metric machine screws and when to use them.

Cheese Head Screws
The oddly named cheese head screw has a rounded head that resembles a wheel of cheese. The thick head provides a deep driving surface for increased torque. With a smaller diameter head, this screw exerts more force over a smaller area, and is easy to fit into crowded assemblies.

Available in:

  • Brass
  • Nylon
  • Stainless Steel A2/A4
  • Steel 4.8/4.8 Zinc

Flat Head Screws
Flat head metric screws feature a flat top and conical bearing surface. This makes them ideal for countersinking applications. When properly installed, the top of this screw is flush or slightly below the mating surface.

Available in:

  • Brass
  • Nylon
  • Stainless Steel A2/A4
  • Steel 4.8 Zinc

Knurled Thumb Screw
These easy-to-use metric screws can be installed and removed by hand. They’re found on everything from lamp shades to computer cases. They’re perfect for any application where quick assembly and disassembly by hand is desired.

Available in:

  • Steel 4.8 Zinc
  • Brass
  • Nylon
  • Stainless Steel A2/A4
  • Plastic

Oval Head Screws
Similar to flat head screws, oval head screws also feature a conical bottom for countersinking. Unlike their flat-headed counterparts, these metric screws have a rounded top, creating a more attractive finish.

Available in:

  • Stainless Steel A2/A4
  • Steel 4.8 Zinc

Pan Head Screws
The workhorse of the metric screw world, pan head metric screws are a general purpose screw that can be used to replace round, binding, and truss-head screws. They have a large diameter, low-profile head that provides high holding power without getting in the way.

Available in:

  • Brass
  • Nylon
  • Stainless Steel A2/A4
  • Steel 4.8/4.8 Zinc

Truss Head Screws
With a larger and lower head than pan head metric screws, truss head screws are ideal for applications with minimal clearance. The large head also allows them to cover large clearance holes in assemblies where additional play is desired, such as sheet metal installations.

Available in:

  • Stainless Steel A2
  • Steel 4.8 Zinc

Wing Head Screws
A cousin to the knurled metric thumb screw, wing head screws are a little easier to use and a little less aesthetically pleasing. These metric screws are ideal for hand-tight applications that require frequent disassembly and attractiveness is not a concern.

Available in:

  • Stainless Steel A2
  • Steel 4.8 Zinc

Binding Head Screws
You’ll find these metric screws on most electrical and audio components. Similar to a pan head on top, it’s what’s underneath that counts. The binding head metric screw has a small undercut that traps stranded wires to prevent fraying.

Available in:

  • Stainless Steel A2
  • Steel 4.8 Zinc
  • Brass

Hex Head Screws
These metric screws are installed using a hexagonal socket or driver. The wide, flat bearing surface allows for greater torque without marring the finish of the mating surface. You can find these metric screws holding together automotive body panels, furniture, and more.

Available in:

  • Steel 4.8, 8.8 and 10.9 Zinc
  • Plain Alloy Steel
  • Stainless Steal A2/A4

 

Putting it All Together
With the variety of metric machine screws available, you never have to “make do” with a screw that doesn’t quite fit your application. Still not sure which metric machine screw is right for you? Contact us and we’ll be happy to help you find the perfect screw for any assembly.

About the author

Mr. Metric is the spokesperson for www.mrmetric.com, an online store for metric fasteners. Get $6.00 flat shipping with no minimum orders, plus advice and best practices for using metric fasteners in any application.

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