×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Metric Specialty Threads

Metric Specialty Threads

Metric Specialty Threads

(OP)
All,

I am looking to find a chart of metric specialty threads.  Our design challenge is that we have a thin wall (1.5mm) that we need a 3.5mm clearance home and then we are going to thread this hole to screw a retaining cap in place.  If we back off the clear hole to 3.3mm we can then use a standard 4 x 0.7mm thread, but I would like to have a finer thread pitch.  Is there anything out there like a 4mm fine pitch thread.

Regards,

Rich.....viking2
 

Richard Nornhold, PE
http://www.ovenind.com

RE: Metric Specialty Threads

Have you tried working the numbers with an imperial thread size?  6-48 is the finest commonly available in that 4 mm range.

RE: Metric Specialty Threads

Fine pitch for M4 is 0.5mm. Taps/dies should be readily available (but perhaps not if you are in the USA)

RE: Metric Specialty Threads

(OP)
Correction:  The wall thickness is now reduced to 1.187mm.  So I guess the question becomes what type of thread could we use that would get us a fine enough pitch to have 3+ threads of engagement.

Rich.....viking2
 

Richard Nornhold, PE
http://www.ovenind.com

RE: Metric Specialty Threads

You can still have 'specials' in metric just like you can have UNS for inch.  Some are even available off the shelf from precision part suppliers like Thorlabs as CBL points out.

Assuming US take a look at ASME B1.13M-2001 section 7.6.

If it's important enough and/or you're making enough of them special threads are perfectly reasonable.  We use them a lot for find adjustment, often parts from Thorlabs or sometimes we have our own made.  In inch things like 80 TPI or even 100 TPI are readily available.  Try finding the equivalent for metric, the link CBL gives may help.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources