Adding a Thread to the Thread.xls

[Anonymous]

Good Day,

Before I waste a ton of time, I was hoping someone can confirm what I am doing is correct.

I am trying to add a thread class to the thread.xls. (that part is ok)

The thread is M26x2.0

I can't seem to find any information for me to simply plug in the values into the .xls, so I am thinking that I have to crunch some numbers. which is fine. I just want to make sure that this image below is the correct the reference for this task.

using the pitch, I should be able to calculate all my min and max values, but the xls has class column and a tap drill column, how would I determine these values??

Any help or direction would be great!!

Thanks!

[Anonymous]

For Class information please see image below....

[Anonymous · Accepted solution]

Also a rule of thumb is Tap Drill = Size - Pitch
Therefore in your case 26-2 = 24  The table you have shown seems to support this as well....

Or you can use this formula....

Metric Cutting Taps

Tap Drill Size =

Basic Major Diameter of Thread - ((% of Full Thread x Pitch in Millimeters) ÷ 76.98)

Example: To Find the Tap Drill Size for a M6 x 1.0 Tap with 70% Thread:

Drill Size = 6.0 - ((70 x 1.0 ) ÷ 76.98])= 5.09067 = 5.1mm Drill

[Anonymous]

Don't you just love non-standard thread sizes 🙂 Fake it, use the M27x2 on your M26 object, then adjust the callout in the part itself or the drawing BOM. or copy that thread file and just change the diameter. Not that it would matter as the threads are simply a picture, not actual cuts in the part, so a M27x2 thread will appear perfectly correct, just leaving the BOM callout to be adjusted.

[Anonymous]

---

@Anonymous wrote:

Don't you just love non-standard thread sizes 🙂 Fake it, use the M27x2 on your M26 object, then adjust the callout in the part itself or the drawing BOM. or copy that thread file and just change the diameter. Not that it would matter as the threads are simply a picture, not actual cuts in the part, so a M27x2 thread will appear perfectly correct, just leaving the BOM callout to be adjusted.

---

Yea, this is what I basically did, I agree, the image means nothing visually, as long as the thread annotation is correctly pulled from the table, however, I like things to be correct, for that just in case instance where I actually need the min and max values (if that ever happens). I don't use a lot of custom threads, so it is good practice to know how to add and modify

Thanks!

---

@Anonymous wrote:

Also a rule of thumb is Tap Drill = Size - Pitch
Therefore in your case 26-2 = 24  The table you have shown seems to support this as well....

---

I never noticed this before, thanks for the tips on classification and pitch size!!

[acad-caveman · Accepted solution]

Courtesy of ThreadPal ( http://mrainey.freeservers.com/METhreadPal.html )

These are the calculated values for an M26 x 2.0mm thread, external and internal:

Metric Units

M26 x 2-6g
Allowance,0.038
Major Diameter Max,25.962
Major Diameter Min,25.682
Pitch Diameter Max,24.663
Pitch Diameter Min,24.493
Minor Diameter Max,23.797
Minor Diameter Min (Ref),23.261
Root Radius Max,0.289
Root Radius Min,0.250
Flat At Root,--
Thread Height (Basic),1.227

M26 x 2-6H
Allowance,0.000
Minor Diameter Min,23.835
Minor Diameter Max,24.210
Pitch Diameter Min,24.701
Pitch Diameter Max,24.925
Major Diameter Min,26.000
Major Diameter Max (Ref),26.513
Flat At Root,--
Thread Height (Basic),1.083

Pitch,2.000
Lead,2.000
Starts,1
Lead Angle,1.479

Included Angle,60.0000

[acad-caveman]

---

@Anonymous wrote:

 Fake it, use the M27x2 on your M26 object, then adjust the callout in the part itself or the drawing BOM. ....

. Not that it would matter as the threads are simply a picture, not actual cuts in the part, so a M27x2 thread will appear perfectly correct, just leaving the BOM callout to be adjusted.

---

Unfortunately, the poor blacksmith actually making the part might just plunk the model into CAM, which promptly recognizes the hole as an M27x2.0 and appropriately drill the hole .... approximately 1mm oversize.

Said blacksmith then curses something under his brow about the engineer, and proceeds to re-make the part from scratch.

[lkirit2000]

Hi Sir,

Please can you help me on this matter below

Hi 

I measured an external thread using thread gauge, it is 6G 1 3/8  1 ½   . Previously I come across the metric and imperial thread.  

This seems different standard. 

Anyone expert in the Forum or anyone who come across this type, Please help me. 

What would be the suitable internal ( NUT ) thread ?

Is there any table for this ?

Rgds

[Paul-Mason]

What is the Number of Threads Per inch?

If it 9TPI then its BSF thread. There IS a  Ø1⅜ x 9 BSF thread but I cant remember if this is in the standard Thread.xls or in a customised Thread.xls that I have

Ø1⅜ is a NONE STANDARD BSW THREAD it is listed in some older books IT IS NOT in the inventor DEFAULT Thread.xls and I've NOT seen it in the customised Thread.xls file that I have ether.