Lock plate threads - HDTDT

[James Wilson Everett]

Guys,

In the 18th c the gunsmith normally made his taps to be rather short and stubby.  Also, they normally were made with the wrench end square much bigger than the thread.  These taps work great when making the gunlock parts.  Here are some original 18th c taps to illustrate.  Check out the posting on 18th c screwwplate use.

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However, there are at least three screw locations in the gun where these normal taps did not work so well.  These locations are the two (or three) sideplate screws and the tang screw.  For these screws the thread is only very rarely square with the lockplate surface, or with the triggerplate/trigger nut surface.  These screws fit into the mating threaded hole at slight angles.  I am sure that the experienced gunsmiths here know about this.  Now, how did the old timers do this job?  Here is a photo of specially made taps to do this job.  Here the tap reaches all the way through the wood of the gun to access the hole from the inside.  This allows the gunsmith to align the sidenails and tang screw exactly.  I am sure that you can envision that tapping the lockplate for the sidenails by going through the sideplate hole and stock hole will ensure that the screw will enter the lockplate at the correct, slight angle.  Also, please notice that the longer tap shafts are smaller than the thread thereby allowing it to pass through the hole.  The normal, short, stubby example shown would not work here.  Let me know if this explanation makes sense to you.

Jim Everett

[Bill-52]

Jim,

Just wanted to thank you for all of your recent topics.  The photos and your explanations have been fascinating, giving me a new appreciation of how these beautiful rifles were built by these very talented craftsmen. 

Bill 

[dannybb55]

Sweet! How do you make the taps?

[James Wilson Everett]

Guys,

There is a fairly detailed description of how the 18th c gunsmith made the taps using the screw plate tool.  Look under the subject "18th c screw plate use" for some photos and descriptions of original 18th c taps and new made taps using the screw plates.  Let me know if you require more information or a detailed description to make the taps.  Thanks for your question here.

Jim Everett

[James Wilson Everett]

Guys,

Here is a set of these same design of lock plate taps from a different collection of gunsmith tools.  These date to the mid 19th c. and were obviously used for the same type of tasks as the ones shown previously.  This suggests a pattern that many - perhaps most - period gunsmiths would have made and used such long reach taps for the specialized job of threading the lock plate side nail holes and the breech tang screw hole as these almost always are at a slight angle to the plate.

Jim Everett

[rich pierce]

Jim, thanks- I've learned a lot from these posts. 

[Eric Laird]

Jim,
To echo everyone else, thanks for all your posts - they're very educational and thought provoking!

It looks like the gunsmith marked the taps with punch marks. I would speculate that it's probably for identification purposes, i.e., he could tell his apprentice, "Get me the number four long tap."

Just one of those random thoughts you've inspired! I guess it's that normal progression from HDTDT to WDTDT - why did they do that?

Thanks again.
Eric

[James Wilson Everett]

Eric,

You are certainly right about the tap punch marking.  The Fry brothers (or was it father & son?) needed to mark the taps to remember which is which.  I only use 3 small taps and 2 breech plug big taps - so it it easy for me to remember even though they are not marked.  But these gunsmiths used a whole lot more, it did make sense that they would have some type of system as you have observed.

Check out this photo of the Fry screwplate and those punch marks.  I have not even tried to figure out which tap matched with a specific screwplate hole.

Jim Everett