Home

Calculations
Contacts
Conversions
Help
Links
Subjects

Letter Drills

This system of numbering drills is no longer used, but may be of use in deciphering old drawings.

Letter	Diameter inches	Letter	Diameter inches	Letter	Diameter inches	Letter	Diameter inches
A	0.234	H	0.266	O	0.316	V	0.377
B	0.238	I	0.272	P	0.323	W	0.386
C	0.242	J	0.277	Q	0.332	X	0.397
D	0.246	K	0.281	R	0.339	Y	0.404
E	0.250	L	0.290	S	0.348	Z	0.413
F	0.257	M	0.295	T	0.358
G	0.261	N	0.302	U	0.368

Previous Page

View links to and from this page

Next Page

Subjects:

Mechanical Engineering

Science & Engineering Encyclopaedia Version 2.4 © 2001-2010