Thread Wires

[Proudpappy]

Been studying up on using thread wires and bought a set from Pee Dee. In the 13th edition of Machinerys Handbook none of the dimensions for the wires for
specific thread per inch match what Pee Dee calls for. Who's right?

[Mcgyver]

The wire diameters don't matter much except that they sit in the trough about right - not at the bottom and with enough proud of the crest that you can measure. Its all formula based, formula will suggest a wire size but diameters around it will still work because they get plugged into, along with the measurement, subsequent forumulas. Here's all the formulas....credit where credits due, this came from Threadcheck's site

[eKretz]

Ideally you'd like the thread wires to rest on the thread flank right on the pitch diameter, but if the angle is right it doesn't really matter.

[LKeithR]

As long as yu can do the math any wire that fits will work. Pee Dee has taken the time to work out
formulas for their wire sizes so you don't need to mess around with the math,,,

[Proudpappy]

Thanks guys.

[sarge41]

As long as you Pee Dee specs with their wires, you're go to go. I been using a set of Pee Dee's for years and no problems.
Sarge41

Edit: Damned spell check, makes me spell like an idiot. I don't need any help in that department.

[Bented]

Measuring threads over wires is annoying at best, I do a good deal of it, if another method is available such as a thread micrometer use it.

If one is truly concerned about PD accuracy simply buy high accuracy matched wires for each job, these are available from such sources as MSC for less then $100.00 per set of three wires.
https://www.mscdirect.com/browse/tn/...navid=12107674

[Video Man]

Been studying up on using thread wires and bought a set from Pee Dee. In the 13th edition of Machinerys Handbook none of the dimensions for the wires for
specific thread per inch match what Pee Dee calls for. Who's right?

13th edition is pretty old, is it possible it specifies National Form threads, which are obsolete and slightly different from the Unified thread standard in use now? I see the above formula charts list National and Unified with the same formulas, but might check if there's a difference with current specs in MH....

[leesr]

Been studying up on using thread wires and bought a set from Pee Dee. In the 13th edition of Machinerys Handbook none of the dimensions for the wires for
specific thread per inch match what Pee Dee calls for. Who's right?

OK FYI every body has covered it very well all ready. I use pee dee set since I first started 35 years ago and it works. how ever best fit wire is more accurate, why because it lays near the
pitch diameter, from personnel experience.
example and rational : sub contract jobs out for thread grind which is close as it gets.
Pee Wees may inspect under size , best fit wire calculation can be in tolerance , so who is correct,
you decide , I chose best fit wires, I order the exact wires from Deltronic or other sources. but this is for aerospace application.
for commercial or home projects it will work fine as long as the customer agrees with your method of measurement and calculation
the trump card is to purchase go and no go gages, designed to the specification, then there is no argument.

[redgrouse]

I have used this for measuring none standard threads and found it works well

https://www.cgtk.co.uk/metalwork/calculators/screwmeasurement

John

[rws]

I use wires all the time on barrel tenons, many custom action makers use wire measurements for their specs. I use a dab of grease to hold the wires in place, takes the frustration out of it all.

[chipmaker4130]

. . .I use a dab of grease to hold the wires in place, takes the frustration out of it all.

Well, I guess I don't really need 4 hands. Thanks for that tip!

[leesr]

Well, I guess I don't really need 4 hands. Thanks for that tip!

yes I do the same dang wires get tiny also a magnetic V block is very helpful

[JRouche]

Very cool read here guys.

Dont forget. Matching sized wires are a must. Or not if you math good.. JR

[eKretz]

Just buy a set of Pee-Dees. Like many others here that's what I use. My set must be over 25 years old by now. Do they still have the free replacement wires if you lose one?