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Precision Screwdriving

This post is not exactly a “Workbench Wednesday” episode, but since it was an issue and solution that cropped up while building Tim’s Mondo Partner Nicholson Workbench I thought I would put it here.

Normally when I am building a Nicholson bench I slam it together with decking or sheetrock screws and a portable drill.  I can usually get one built on a day that way.  But with Tim’s bench, because of the setting for the final location of the bench, a restored 18th century log barn outfitted to be an 18th century workshop appropriate to the long-rifle making that Tim does, he wanted the presentation of the bench to reflect the 1780 Virginia frontier.  Hence, no decking screws.

Instead I fell back on my old reliable supplier, Blacksmith Bolt and Rivet, who still provides excellent steel screws of the slotted-head woodscrew variety.  The quality of these screws versus the usually crappy modern plated screws from the hardware stores makes them worth the effort to obtain and use.  For starters, I generally find that about 1 in 25 of the modern hardware store screws actually rings off when I lean on them too much, and the metal is so soft that the heads get boogered up even more often during installation.

Using high quality slotted screws is not without drawbacks either.  For starters the screwdriver tip has to fit the slot precisely in both width and length in order to get full efficiency in the driving.  Plus, driving large screws by hand is a lot of work and in the case of Tim’s bench I was driving in over a hundred 2″ #14 screws.

The screwdriver tips I had to fit into my brace were not a perfect fit to the slots of the screws I was using so I took fifteen minutes to make a new one that fit the #14 heads precisely.

I started with the oldest, raggediest 1/2″ wood bit in my collection, 1/2″ being the width of the #14 head.  With my handy dandy Dremel-type tool (Craftsman, circa 1975 and still going strong) I took off the central tip of the bit.

Using a grinding wheel followed by a coarse diamond plate I made the tip perfectly flat and the thickness of the bit to fit the slot exactly, so precise that it literally could be inserted into the slot by hand but still was snug enough to stay there.

With this new precision wood screw bit I was able to drive the dozens of screws easily into the pre-drilled holes.  All made possible by the fact that I did not throw away a decrepit drill bit.