Looking for 4mm-.075 fillister head screws

R

rangerm1a

Plastic

Joined

Jun 15, 2008

Location

Nashville, TN

• Aug 25, 2009

• #1

I'm building a component to fit an existing item that uses 4mm -.075 fillister head screws. I need some longer ones but can't locate them thru any of the big distributers like MSC, Grainger, McMaster Carr, Fastenal, Small Parts, Berg, Lowe's, or Home Depot.

I have a tap and die this size so either I'm not looking in the right place or they've all been destroyed.

Any info would be helpful. Thanks.

 

L

L Vanice

Diamond

Joined

Feb 8, 2006

Location

Fort Wayne, IN

• Aug 25, 2009

• #2

M4 x .7 is the common ISO thread. You probably meant you are looking for M4 x .75, which is probably in an older component. A .075 mm pitch is 339 TPI, really fine!

Larry

 

R

rangerm1a

Plastic

Joined

Jun 15, 2008

Location

Nashville, TN

• Aug 25, 2009

• #3

Yeah I was going off of what the tap read which was the 4mm - .075 and the M4x .7 is all anybody has but obviously doesn't fit. I'm thinking about making some but didin't want to go that route if I could find some.

 

L

Limy Sami

Diamond

Joined

Jan 7, 2007

Location

Norfolk, UK

• Aug 25, 2009

• #4

FWIW;- I can't help on where, but IIRC 4 x 0.75 is an old German DIN standard, possibly pre WW2 if that's any help.

 

L

L Vanice

Diamond

Joined

Feb 8, 2006

Location

Fort Wayne, IN

• Aug 25, 2009

• #5

And Google reveals that the rear sight screw for a Model 1938 Italian Carcano carbine has that thread. More likely old than new design, so new screws would be a DIY job.

Larry

 

R

rangerm1a

Plastic

Joined

Jun 15, 2008

Location

Nashville, TN

• Aug 25, 2009

• #6

Thanks for the help. I guess I'll get to making some then.

 

K

KilrB

Stainless

Joined

Feb 18, 2007

Location

Angleton, Texas

• Aug 25, 2009

• #7

Making which one?

M4 x .75 or M4 x .075?

 

R

rangerm1a

Plastic

Joined

Jun 15, 2008

Location

Nashville, TN

• Aug 25, 2009

• #8

I guess I'll make the M4X .75 which is confusing to me because I have a tap the reads exactly, "4mm - .075", but I can only find a die labeled as M4x.75, so I can only guess that they coincide, although I know that .75 and .075 aren't the same. I just chalked it up to a metric thing, or the tap is mislabeled. I don't know who made the tap, but it was made in the states. I've had this hassle all day and can't get a straight answer. So if I've got a tap labeled as 4mm-.075, then a die labeled as M4x.75 will not work, is that what I'm understanding? Or is possible that the tap is mislabeled?

 

L

L Vanice

Diamond

Joined

Feb 8, 2006

Location

Fort Wayne, IN

• Aug 25, 2009

• #9

Well, .75 mm is the same as .075 cm. People who understand and use the modern metric system call out thread pitch in mm. But 60 to 100 years ago, Americans called out metric threads in threads per centimeter, which is not at all the same as the modern metric pitch designation. For instance, a 1 mm pitch is the same as 10 threads per cm and .75 mm is 7.5 threads per cm.

You said the tap is US made, so maybe it was made when Americans did not fully understand how to describe a metric thread, but had adopted the metric pitch scheme. I expect the tap will fit your existing holes. You should have no trouble eyeballing the difference between 34 and 339 threads per inch.

Larry

 

R

rangerm1a

Plastic

Joined

Jun 15, 2008

Location

Nashville, TN

• Aug 25, 2009

• #10

That makes sense. I don't deal alot with metric so this whole day has been a nutroll trying to make sense of it and come up with a solution. Thanks for taking the time to explain that.

One thing though, the tap doesn't appear to be that old, which aided in the confusion. I'll know for certain tomorrow when the M4x.75 die arrives and I make the first screw. Thanks again.

 

J

juergenwt

Stainless

Joined

Feb 2, 2008

Location

Wheaton, IL.

• Feb 22, 2020

• #11

Standard M4 has 0.7 mm pitch.There is also M4.5 with a 0.75mm pitch.
There is NO M4 x 0.075!

Check if you don't have mislabeled 8-32 or 8-36.

There is also a Metric Fine M4x.2,M4x.25, M4x.35 and M4x.5 Very rare!!

 

sfriedberg

Diamond

Joined

Oct 14, 2010

Location

Oregon, USA

• Feb 22, 2020

• #12

This thread (M4x0.75) came up in another thread (forum) a few days ago. IIRC, it was previously used widely in Japan, but is no longer a preferred thread there.

No matter what is stamped on it, the OP certainly does not have an M4x.075, as you'd have a hard time distinguishing .075 threads from a rough-turned cylinder. .075 != 0.75

 

J

john.k

Diamond

Joined

Dec 21, 2012

Location

Brisbane Qld Australia

• Feb 22, 2020

• #13

The 4mmx .75mm thread is old metric standard,adopted by the Japanese as JIC ....there are a number of other sizes too ,which dont correspond with ISO....Its a common thread in pre 1970s Japanese consumer goods ,like cars ,motorbikes ,and electricals......and machine tools .