Starrett 174 Tap Handle.. Need Internal Threads Please.

woodchucker

woodchucker

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Just picked up a 174 tap handle for $1. I believe the smallest handle they make. it was missing the threaded side of the handle. Can someone give me the size of the screw, and TPI please. Would like to make a new handle.
A pic would be great too, if you could.

Thanks
Jeff.SDC11748.JPG
 
I'm sure it's a non-standard thread. Pull out your taps and start trying one's until you get one that starts in the thread. Don't force it! If it will not go all the way in. The trick to it is to get one to start that has the thread pitch that matches the closest. Since your going to make the missing handle, tap out the hole with the tap that fits the hole the best.
BTW- Push all your Metric taps the the side. Starrett does not use Metric threads in things like this. They will be Imperial thread pitches. Ken
 
After posting I was putting the screw back in and noticed it had a bit of a wiggle going in. I would try a 1/4 - 28 allen screw and if it fits just turn the end down so that any mushrooming on end will still allow removing.
 
Just tried a 1/4 - 28 screw as well as metrics. It is definitely one of the odd starret threads. I don't have wires to check the pitch diameter or I would do that for you also.
 
Billh50 said:
Just tried a 1/4 - 28 screw as well as metrics. It is definitely one of the odd starret threads. I don't have wires to check the pitch diameter or I would do that for you also.
Click to expand...

It won't be metric!!! But at .222" OD could have been 12-28 NF thread?
 
A 12-28 has a max major of .215
So I really believe it to be one of Starret's own threads. Back in the day many of the machine manufacturers had their own threads. I remember re-tapping many holes for standard threads as I could not see paying $5 for one screw when I could buy a standard for $0.10
 
Whittle a pencil down. Stick it in the hole and rub it on the threads. Then,check the pencil with a thread gage. Not hard to do.

If it's an odd thread,turn out the missing handle on your lathe. I have never NOT been able to make threaded parts to fit 18th. C. parts that were missing threaded pieces,even left handed.

Don't take the threaded part out of the chuck. repeatedly try screwing it into the hole and sneak up on it till it screws in. That is the simplest way to do the job rather than trying to figure out the actual diameter of the needed thread.
 
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