Percent Thread Called Out on Print

[rsm7400]

Good morning Eng Tips Community.

I have a print that is calling out a thread as listed below:

M3 x 0.5 Thru
55% Thread

What does the 55% thread mean? This is the first time I have seen this on my 1000's of unique part numbers.

Thanks

________________________________
Ryan M
Quality Engineer
3d Printer Hobbyist

 

[btrueblood]

I'd assume they want only 55% of the nominal thread height, i.e. drill an oversize hole prior to tapping. But, do they really mean 55% min. height? I'd be asking the person who made the drawing.

 

[rsm7400]

I did end up verifying with the customer. This is what they want. They will be epoxying some components into the threads on our part and wanted a little extra room. We are using the chart in the link below for slightly oversized drilled hole.

[URL unfurl="true"]http://www.balax.com/catalog/thredshaver-taps/metric-and-pipe-thredshaver-hole-size-chart[/url]


________________________________
Ryan M
Quality Engineer
3d Printer Hobbyist

 

[Tunalover]

This is why I always do a section view of any blind threaded hole.

ElectroMechanical Product Development
(Electronics Packaging)
UMD 1984
UCF 1993

https://www.youtube.com/watch?v=BKorP55Aqvg