NASA Tech Briefs

Innovations developed by NASA and its industry partners in a wide array of fields.

CNC Machining Design Guide

Optimize your designs, reduce machining time, and lower your costs.

Metal 3D Printing Design Guide

Direct Metal Laser Sintering (DMLS) 3D printing for parts with reduced cost and little waste.

Design-2-Part

How OEM's can make their parts better, faster, and more efficient.

more free magazines

Materials

Design

Processes

Units

Formulas

Math
Counter Bore/Sink
  • Counter-sinking is often done to accommodate heads of flat head screws. However as can be seen from the figure, there is a sideways component of the thrust which could split the countersink due to the generated hoop stresses

  • Counter-boring is done to accomodate pan-head, fillister-head or round-head screws or other screws with flat-bottomed undersides.

  • Counter-bored screws exert only force in the axial direction, thus operate mostly under compression, with no sideward component to the applied force vector. Such design is inherently more robust than counter-sinking.