Diameter (mm) Length (mm)
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4mm 25
30 8 x 1 1/4
35 8 x 1 3/8
40 8 x 1 1/2
How are machine screws sized?
Their size is described as diameter, number of threads per inch (if used with a nut or in a threaded hole), and length in inches. ... Machine screws are often found in sizes of: 0, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14—the larger the number, the larger the screw.