Attention!

Please do not mistake this thread for the Whitworth Fine Thread BS 84. This thread is an old one which is not used anymore. The nominal diameter and the pitch are mentioned in millimeters or in TPI.
Used in locomotive construction approx. until 1975.
The flank angle is 55°.

Repair sizes for locomotive construction, DIN 30284.

Diameter for bolt and nut
Thread Size	Tapping Drill Size	Core Area	TPI	Pitch
	mm	cm2		mm
W 14 x 1/12" DIN 30284	11.290	1.00	12	2.117
W 15 x 1/12" DIN 30284	12.290	1.18	12	2.117
W 17 x 1/11" DIN 30284	14.042	1.54	11	2.309
W 18 x 1/11" DIN 30284	15.042	1.77	11	2.309