How to thread?

[Mark_Larson]

Is there an easy way to thread, other than buying a lathe/mill?

I have a Solitaire mod in mind, but to get the most use out of it i want to shorten it the way Roth did his MMM and rethread it the same way. Any ideas?

 

[Wylie]

You may want to look into a tap and die set but chech your thread pitch first. This may work for you although I am not totally up on what you have going. The pitch is the number of threads per mm or inch and don't try to measure it because it would be very hard to do with any sort of rule. A special feeler gauge is used to measure threads and is the only real way to do it right. It may be that material needs to be milled from the diameter first so the tap and die may just not be the answer but I thought I would chime in anyway. Good Luck and Merry Christmas.

 

[Rothrandir]

using a tap and die (tap for inside threading, die for outside) is the easiest way to tap.

a tap is kind of like a screw, but has cutting surfaces on the sides, to cut the threads as you put it further in. a die is the same, but in reverse.

as wylie said, some flashlights will need to be bored a little bit before they can be tapped.

 

[McGizmo]

Pitch gauges are the best way to determine the thread pitch but in a pinch, you can lay the threads of a known screw or bolt into or onto an unknown thread and check for a match. A good match will show in profile with the two threads mating across the length of engagement. Imperial or "american" threads are measured in threads per inch (TPI) whereas metric threads are measured as the axial length of a single thread. I.E. a metric 12x .75 is a 12 mm diameter with the thread pitch of .75. .75 mm is measured from the point of one thread to the next. Most fasteners will be designed with a thread engagement from 60 to 80% I believe. Flashlights can get by with much less, typically. That is to say that the threads don't have to be real deep or full cut. An oversized bore will allow for easier tapping and you will still have enough thread engagement for fit and function. The finer the pitch, the more precise you need to be with your pilot hole to be tapped and OD to be chased.

 

[Mark_Larson]

Thanks for the help. Now, where would i buy a tap&die set, and could anyone tell me what the measurements are for the Solitaire's battery tube (tail end)?

 

[Mark_Larson]

Could anyone post more info on the tap&die set, and where would i buy one of these?

 

[Rothrandir]

travers is probably the best place to get flashlight sized taps and dies. you can buy tap and die sets in magazines or even in some stores, but they woule be too small for flashlights for the most part.
even so, it is nice to have a tap and die set, in case you need to tap a hole for a set screw, or to hold a joint or something.

 

[darkzero]

I get all my flashlight threading stuff from JTS Machinery & Supply . They stock hard to find uncommon sizes & have no minimum order like other machinery supply stores.