HP 5961-0509 manual Courier is very close to 60% of an Em, and 30 = 1 ÷ 0.64 ÷, Vendor

The following formula can be used to as a rule of thumb for computing a maximum recommended pitch:

	The character (“contour”) width in the above formula is expressed
	as a percentage of an Em. For example, the width of characters in
	Courier is very close to 60% of an Em, and 30 = 1 ÷ (0.64 ÷ 72) .
	(The width of characters in Letter Gothic is approximately 50% of an
	Em. For other fonts, refer to the font metric data supplied by the font
	vendor.)
Note	If a scalable fixed-space font is selected using an ID number, send the
	Pitch command to specify the size; otherwise, the size is determined
	by the pitch characteristic value of the former font (as listed in the font
	select table) See “Font Selection by ID Command” later in this
	chapter for more information.

Example

To specify 10 pitch for the primary font, send:

EC(s10H

To specify 16.66 pitch for the secondary font, send:

EC)s16.66H

EN Pitch Command 8-11