$re = '/(?:
\G(?!\A)[-\/]
|
^
[^-\d\/\n]*+
(?>[-\d\/]+[^-\d\/\n]+)*
)
\K \d++ (?![-\/]\D)/mx';
$str = '
Name 789, 10-mill 12-27b
Manufacturer XY-2822, 10-mill, 17-25b
Other Manufacturer 16b Part
Another Manufacturer FER M9000, 11-mill, 11-40
18b Part
Maker 11-31, 10-mill
Maker 1x or 2x; max size 1x (34b), 2x (38/24b)
Maker REC6 15/18/26b. Square.
Producer FC-40 11-13-16-19-22-25-27-30-34b
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php