Machine Screw Thread Sizes

Posted on by
Machine Screw Thread Sizes Rating: 9,9/10 419 reviews

A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a straight thread and the latter called a tapered thread. A screw thread is the essential feature of the screw as a simple machine and also as a fastener. The mechanical advantage of a screw thread depends on its lead, which is the. Screw Thread Size and Pitch Outside Diameter of Screw (in.) Tap Drill Size Decimal Equivalentof Drill Size Screw Thread Pitches and Tap Drill Sizes Smithy - Detroit Machine Tools Jump to Navigation. US Micro Screw offers a variety of standard and specialized thread sizes. Aside from our standard small screws we can build your custom fasteners in any variety of customizable screw options: thread size, counter sunk and pan head size (down to 0.2 mm), length, drive type (Philips, slotted, Torx, square, hex, etc), finish and coating. A #8 screw size is.164 fraction of an inch. The diameters listed in the chart below are in fractions of an inch, so the #12 is just shy of 1/4 inch. A more detailed table with thread count can be found below, along with tap drill sizes. Detailed screw sizes charts. Screw and Tap Drill sizes. Read the first letter of the size. This the largest diameter: the measurement of the screw on the thread. Unified screw diameters are measured in inches - lowest to highest as 0 to 10. Measurements equal 0.060' + 0.013' x measured diameter.

  1. Metric Machine Screws Size Chart
  2. Common Machine Screw Thread Sizes
  3. Large Screw Thread Sizes
Active1 year, 6 months ago

I'm going to be building a workbench, so I've been 'screw shopping.' I need some explanation on the sizing of screws when they are advertised as (example) 6 x 3/4'. I know that 3/4' is the length of the screw, but what does the 6 mean?

No splits of types or categories. A full list is shown at the end of all entries and their grades.All choices would still have special trophies such as Most Improved Since Last Year, Entry With Most Potential, and Most WTF (Polygon Jim) Trophy.Voting Form:Once the people have decided we will announce further details of this year's contest. Top 3 Retro overall, Top 3 3D overall, Top 3 2D PC overall, Best looking Retro entry, Best looking 3D entry, Best looking 2D PC entry, Best sounding Retro entry, Best sounding 3D entry, etc.Choice 3: Overall list of all entries graded. Sonic cd rom hacks. Sorry for the delay, these things happen, but the links have been up since Sunday.

Calvin AllenCalvin Allen
5542 gold badges7 silver badges13 bronze badges

7 Answers

'6' is a #6-size screw. Screw gauges are a measure of the head size and shaft size, and are roughly linear but not quite a 1:1 relationship (a #8 screw is a little less than twice the diameter of a #4 screw). There isn't a good system for converting gauge to a calibrated measurement, so you're best off consulting a table like this: http://hingedummy.info/screwinfopage2.htm

Screws have three basic measurements: gauge, threads per inch, and shaft length in inches. So, you may also see a measurement like 6-32 x 1 1/2'. This means it's a #6 diameter, with 32 threads per inch (almost double the normal thread count as a standard wood screw) and an inch and a half long. When the middle number is absent (6 x 1 1/2'), the screw has the 'normal' number of threads per inch for that size and type of screw (for #6 wood screws that's 18).

KeithSKeithS
12.9k7 gold badges35 silver badges70 bronze badges

You might find this table useful as well..

See also here and the original, here.

Disclaimer: I wrote the table after more than 30 years in trade (builder/carpenter).

handymanhandyman

The sites mentioned in previous answers are nice, but are not comprehensive. There are several different ways of measuring the diameter which is critical to understand based on the application. For example, for placing a screw in a tapped hole, the important diameter is the major diameter (the largest diameter around the shank including the threads). A chart with those measurements is given here:http://www.engineersedge.com/screw_threads_chart.htmalong with explanations of the different measurements:https://en.wikipedia.org/wiki/Screw_thread#Diameters

Peter DPeter D

Back in the last century when we were not sure of a screw's gauge, a reliable rule of thumb was to measure the diameter of the countersunk head in inches. Deduct from that measurement 1/16', and then count the number of 1/32' remaining. So a screw head with a diameter of 1/4' was a 6 gauge, 5/16' was an 8 gauge, 3/8' was a 10 gauge and so on.

John DavidsonJohn Davidson

McMaster-Carr also has a good description of a lot of information concerning the many kinds of threaded fasteners available. http://www.mcmaster.com/#about-machine-screws/=h8mmn6

whatsisnamewhatsisname

Metric Machine Screws Size Chart

JasonJason

The way I was shown was to measure across the screw head in1/16th's double it and take away 2. ie. if it is 5/16th's across double to 10 - 2 = 8

John BignellJohn Bignell

Common Machine Screw Thread Sizes

protected by StevenJan 28 '15 at 2:13

Thank you for your interest in this question. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).
Would you like to answer one of these unanswered questions instead?

Large Screw Thread Sizes

Not the answer you're looking for? Browse other questions tagged screws or ask your own question.