|Whitworth size (in)|Core diameter (in)|Threads per inch|Pitch (in)|Tapping drill size|
|---|---|---|---|---|
|1/16|0.0411|60|0.0167|Number Drill 56 (1.2 mm)|
|3/32|0.0672|48|0.0208|Number Drill 49 (1.85 mm)|
|1/8|0.0930|40|0.025|Number Drill 39 (2.55 mm)|
|5/32|0.1162|32|0.0313|Number Drill 30 (3.2 mm)|
|3/16|0.1341|24|0.0417|Number Drill 26 (3.7 mm)|
|7/32|0.1654|24|0.0417|Number Drill 16 (4.5 mm)|
|1/4|0.1860|20|0.05|Number Drill 9 (5.1 mm)|
|5/16|0.2414|18|0.0556|Letter Drill F (6.5 mm)|
|3/8|0.2950|16|0.0625|5/16 in (7.94 mm)|
|7/16|0.3460|14|0.0714|Letter Drill U (9.3 mm)|
|1/2|0.3933|12|0.0833|Letter Drill Z (10.5 mm)|
|9/16|0.4558|12|0.0833|12.1 mm (0.4764 in)|
|5/8|0.5086|11|0.0909|13.5 mm (0.5315 in)|
|11/16|0.5711|11|0.0909|15 mm (0.5906 in)|
|3/4|0.6219|10|0.1|16.27 mm (0.6406 in)|
|13/16|0.6845|10|0.1|18 mm (0.7087 in)|
|7/8|0.7327|9|0.1111|19.25 mm (0.7579 in)|
|15/16|0.7953|9|0.1111|20.75 mm (0.8169 in)|
|1|0.8399|8|0.125|22 mm (0.8661 in)|
|1 1/8|0.9420|7|0.1429||
|1 1/4|1.0670|7|0.1429||
|1 1/2|1.2866|6|0.1667||
|1 3/4|1.4939|5|0.2||
|2|1.7154|4.5|0.2222||
|2 1/2|2.180|4|0.250||

Question: what is the top amount of threads per inch?
Answer: 60