Pneumatic Fitting TPI (Air Tool) thread, help!!! Solidworks project

[mikew13]

I am working on a solidworks model based on a el cheapo campbell hausfield 1/2 impact.

Female fitting which comes already installed on the air tool (male fitting threads into this fitting). Threads aren't making ANY sense. Did go to ACE to get a idea of thread size after metric pitch gauge didn't match, but 1.5 metric pitch was close, and purchased standard TPI gauge.

Heres what I got:

External Threads:

Major Diameter: About .663"
Minor Diameter: .597"

18 TPI seems to fit the best but 1.5 metric pitch is close

Internal Threads:

Minor Diameter:
About .597"

18 TPI seems to fit the best but 1.5 metric pitch is close.

Whats the deal here? CHs manufactured with oddball thread sizes in China?

Anyway anyone experienced with threading and knurling on solidworks? Could use some pointers. Thanks!

 

[csargents1546]

The threads should be a standard NPT thread. Every air tool that I have is a standard 1/4 npt ******. Some might be 3/8 npt.

 

[Outlawmws]

http://www.tracepartsonline.net/%28S%285vtd5ub45hxhrxrc51xouybh%29%29/partdetails.aspx?PartID=10-08032005-058750&sk_Reference=&Class=trace&ClsID=/ROOT/C23/&fwsid=

 

[afazz]

To cut a thread in Solidworks, draw the profile and draw a helix. Then do a sweep-cut to cut the threads. Depending in the version you're running, Solidworks has trouble building helical surfaces. I have had success cutting one turn at a time, then editing the helix and rebuilding the features. To cut an NPT thread, draw a tapered helix. Helical surfaces cannot be mated, you must constrain the parts using coincident or concentric mates to other features.

 

[mikew13]

http://www.tracepartsonline.net/%28S%285vtd5ub45hxhrxrc51xouybh%29%29/partdetails.aspx?PartID=10-08032005-058750&sk_Reference=&Class=trace&ClsID=/ROOT/C23/&fwsid=

So NPT is tapered? I suspected NPT but nothing I had on hand matched. Thanks

 

[mikew13]

 

[vintagefan]

Almost guarantee it's 3/8" NPT.

3/8 specs

pitch 18

nominal OD 0.675

tap drill size 0.5625

 

[bronc3buster842001]

I have a couple of CAD models of fittings that have threads on them.

Im using Alibre Design so I can only export them as an .STL file.

I can send them to you if you can open them.


EDIT: I exported and was able to open it with the Solidworks EDrawing viewer.

 

[steve-l]

Not all air tools use NPT. In Europe the standard is NPS, same pitch, same diameter, no taper. Seal for NPS is acheived using a flange seal. In metricvill NPT is generally used for water and low pressure hydraulics.
Steve

 

[mikew13]

The problem I had in the beginning is that the "show cosmetic threads" was turned off in the annotations. I figured that out. I used the hole tool with 1/4-18 NPT spec'ed and 3/8-18 NPT speced for the external cosmetic thread.

Its all good now.

Does anybody have a nice used USA made thread pitch gauge for sale?