Free Metalworking Project Plans: T-Handle Tap Wrench / “Tapping Fixture” (Lathe, Mill)
Material: Steel
Units: (in)
This “Tapping Fixture” project is completed almost exclusively on the lathe, with only a few steps requiring the mill. This project is a bit more challenging than the Spring Center or the Soft Face Hammer because it requires single point cutting of internal threads, and boring of an internal thread relief.
Feel free to pick a more coarse thread than what’s called out in the plans (11/16-24 UNF is a bit fine, a coarser thread would be easier for a beginner to cut – especially when cutting the internal threads). Just remember, if you decide to change the thread pitch, remember to do so on BOTH parts!
The title of this post requires a bit of explanation. If you search the web for “T-Handle Tap Wrench” you’ll find these:
If you search the web for “Tapping fixture” you’ll find something that much more closely resembles this project:
Oddly, the plans call this project a “Tap Handle”. So as you can see, there are several ways that people use to refer to this tapping tool. To take it one step further, it would be more appropriate to call this device a “Jig” since “Fixtures” typically hold onto the part in question. But I digress …
Here’s what you need to know. The tapping fixture that you’ll make from these plans consists of a T-Handle Tap Wrench that fits smoothly into a Tapping Fixture. The Fixture itself has has a flat base with a “V” cut in it. This base allows the user to tap a hole on a flat surface like this:
Or the user can use the “V” in the base to help steady the Tapping Fixture and keep it perpendicular to a cylinder:
To complete the project you’ll need a ball detent like the one pictured below to hold the Tommy Bar in place. 
Here’s an image of all the parts required for your Tapping Fixture:
I had a hard time figuring out how to cut the groves in the jaws. Eventually I held the jaws (one at a time) in a Toolmaker’s Vise, which was held in the vise bolted to the X/Y table on the mill. Then I tilted the head of the mill at a 45 degree angle and used a 1/2″ 4 flute end mill (not shown). Here’s a Picture of how I set that up:
Below is a link the plans in PDF format. Leave a comment if you have a question or get stuck.
Tap_Handle.pdf (106.9 KiB, 2,033 hits)
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Tags: Advanced, Lathe, Units (in)
July 11th, 2009 at 8:31 AM
Hi,
I’ve been looking for a tap wrench design similar to the Starrett for a while and was happy to find this one. One helpful thing you might add to the description is the size range of taps that it handles – Starrett has 3 wrenches and it’s unclear whether this wrench replaces all or just one.
It would also be nice to know who provided the plan and the original website if there is one. The Magicala copyright flap in 2007 caused many of the plans on the net to disappear so I’m concerned that your site might run into this unless you have explicit permission from the copyright holders.
Regards, John
July 11th, 2009 at 11:20 AM
Hi John, I’m glad you’re pleased with the plans. I’ll have to look into the sizes of taps that fit it, or I can just mic how far the jaws will open, and go at it from that direction. I’ll have to get back to you on that.
The plans are from Bates Technical College in Tacoma, WA. The plans are used here (along with a few other plans) with gracious permission from the head of the machining department at Bates, Bob Storrar. As far as other plans are concerned, I try to ask for visitors to submit their own plans rather than spending the time surfing the web myself looking for plans. That way by submitting their own plans, their permission is implied. The only thing I have to worry about at that point is trying to make sure that the plans they submit are their own and not the work of someone else.
However, if you or anyone else sees something on the site that you think is in violation of copyright laws, please let me know. This site is meant to be a resource to beginner machinists. It will take a lot of time to earn the respect of the machining community, and keeping things “above board” is just one of the ways that I hope to eventually earn that respect.
Thanks for your concern, and I’m glad you like the plans. Please post a picture when you finish your project. I’d like to see it.
Tyler Youngblood,
Seattle, WA
July 11th, 2009 at 11:37 AM
John, do you have a link to the copyright info you mentioned. I Googled “Magicala copyright flap 2007″ but I only found your site. Could Magicala be misspelled? I also visited http://www.copyright.gov/ but I couldn’t find a change there from 2007 either. I’d like to read over the changes to make sure that I’m in compliance.
Thanks in advance.
Tyler
August 2nd, 2009 at 12:48 PM
Hi Tyler,
Here’s a picture of my completed tap wrench as you requested:
http://img190.imageshack.us/img190/2444/tapwrench.jpg
I made it more along the lines of the Starrett 93-B which it resembles internally and in size. It wasn’t difficult to make but took quite a while due to the number of setups needed. A good exercise for a shop class, just as intended.
I added a link to your site from mine. Thanks for hosting all these plans, it is a nice resource for HSMs.
Regards, John
August 2nd, 2009 at 2:10 PM
Excellent John, thanks for sharing your image. I’m glad you enjoyed the project. You did an especially nice job on the finish and the knurl. I like it!