Drilling Countersink Holes for Wood Screws Sizes

Drilling Countersink Holes for Wood Screws

Countersink Chart for Drilling Wood Screw Holes



Drilling Countersink Holes for Wood Screws

If you want the head of each screw to sit flush with the surface of your wood, it’s time to start drilling countersink holes. Not only does this practice add to the overall appearance, but certain wood projects require a perfectly smooth surface. Since countersinks add another step to every screw hole, we’ve created a quick-reference chart to speed things up for you.

Referencing Our Countersink Chart

When referencing the chart, keep in mind that we chose sizes that would accommodate the most common screw head diameters. Thus, screws with a narrower head may want to consider a smaller size. Likewise, abnormally large screw heads may need extra room to accommodate their width. If in doubt, go with the recommended size. Unlike pilot holes, countersink holes cannot afford to run on the tight side. Similarly, it’s much less problematic to overestimate the size of a countersink hole as it is with the initial pilot hole.

Determining the Depth of Each Countersink Hole

Given all the different types of screw heads and wood species, pinpointing a single depth for each countersink hole is impossible. Thus, you will need to adjust the depth of your countersink holes to accommodate your given circumstances. For anyone working with softwood, the countersink hole should measure less in depth than the height of the screw’s head. The reason being is that less-dense wood species will compact upon pressure from the screw, which allows for the head to push in. On the other hand, denser hardwoods are much more stubborn and require the area for the screw head to be completely cleared. In any case, be mindful that you can always increase the hole’s depth, but can never shrink it.

Accommodating the Extra Step in Drilling Wood Screws

Most people skip the countersink hole to save time. However, this often results in lower quality work and increases the likelihood of an error. To keep countersink holes in your process, consider drilling them all at once. Swapping out different drill bits is time consuming so streamlining the countersinking step will save you time. Also, drilling a countersink hole will allow for the screw to enter more smoothly. As a result, you’ll encounter fewer stripped screws and less wood splitting. So when it’s time for your next DIY wood project, don’t be lazy and countersink your screw holes.

 

Wood Screw Size Countersink Drill Bit
0 1/8
1 1/8
2 3/16
3 1/4
4 1/4
5 5/16
6 5/16
7 5/16
8 3/8
9 3/8
10 7/16
11 7/16
12 7/16
14 1/2
16 9/16
18 5/8
20 3/4
24 3/4

Recommended Tools for Countersinking Wood Screws:

Best Countersink Drill Bits for Wood Screws

IRWIN Metal Countersink Drill Bits

Why we like it:

  • Suitable for machinable metals, wood, & plastic
  • Black oxide coating provides greater longevity
  • Essential sizes are covered in the set
  • Overall decent quality & built to last

 

View it on Amazon




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