I doubt I'm the only one whose wondered this so will go ahead and ask it. Laugh if you want if you will, but I don't understand how to read screw notation for metric. I know what I need as I can look it up, but don't understand what each element represents in the notation.

I work in IT and computer software has defined notations/syntax, so I have no problem picking it up. Just don't know what it is,

Example: Losi 8ight 2.0 needs a screw, the size is 5-40 X 1/2" BH Screws . My D8T lost one that was M2.2x4.8mm. These seem like different notations. Is that true?If so, what are the types of notations?

Can someone specifically break down those two notations above?

i.e. Where is the head, thread design, lenth/width, etc. noted?

Thanks!</p>

We will not laugh at this question because there are metric and standard types of screws. Your new kit which is a Mugen and HPIis Metric threads and lengthandthe Losi 8 is all American which uses Standard threads and lengths.

There is a huge difference between the Standard "American" and the rest of the world who uses Metric styles. I run into the same problem with my Team Associated with are all Standard stye screws and the rest of my R/Cs are all metric. I have to have 2 sets of tools to work on each model. Standard and Metric tool sets.

This is THE biggest problem with both Losi and Team Associated. Outdated imperial measurements (say what you like, it is outdated).

I only realised Losi was using Imperial a few weeks ago...still shaking my head now. A screw is a screw but it is so much eassier if they all use the same.

5-40 X 1/2"

It's a #5 screw (1/8" diameter) with 40 threads per inch and is 1/2" long.

Machine screw diameters go from zero to 12 in size, and then are normally in inches after that. See the chart in the link below:

http://en.wikipedia.org/wiki/Unified_Thread_Standard


M2.2x4.8mm

This one is sort of misleading as it leaves out the thread size, but it is a 2.2 mm diameter screw that is 4.8 mm long (and presumably a fine thread of 0.25mm between threads as they don't make a coarse thread machine screw with a 2.2mm diameter)

Typically, one might see a M4 - 0.7 x 6

This would mean a 4 mm diameter screw with threads spaced 0.7 mm apart and a length of 6mm

See fine and coarse metric screw charts in link below:

http://www.engineeringtoolbox.com/me...ads-d_777.html

Notes:

In general, machine screw length is from under the head to the end of the threads except for countersunk screws where it's the total length from the top of the head to the end of the threads.

Note English screws use threads per inch, but metric use mm between threads.

Solid info Argess!