Page 203 - b.safe catalog

UNF 1/4" 28G
. Mainly used in chromatography / HPLC applications . in the USA
Digits 28 G and 32 G stand for the number of thread pitches at a length of one inch (25,4 mm)
Example:
UNF 1/4" 28G – O. D. = 6,2 mm
UNF 1⁄4” 28G versus M 6
b.safe Fittings come with the most common HPLC thread UNF 1⁄4” 28 G without exception. In addition, fittings and distributors with the very similar thread
M 6 exist. These threads can only be distinguished
by exact determination of their outer diameter or by using a test mandrel (it is possible to screw in a tube end fitting in the counterpart of the other thread for at least 2-3 rotations). The UNF 1⁄4” thread has an outer diameter of 6.35 mm, the M 6 thread has exactly 6 mm (work tolerances are possible). We recommend
to use only the UNF 1⁄4” 28G thread to avoid confusion and double inventory.
O. D.
Measurement chart
O. D. mm
20,8 13,2 10,0 9,6 6,2
16,5
13,0
9,9
7,9
6,0
NPT 1/8“
G/R 1/8“
UNF 1/4“
M6
M 10
G/R 3/8“
G/R 1/4“
NPT 1/4“
b.safe TECHNICAL INFORMATION 171
Pitch
28 thread pitches on 1" = 0,91 mm
Pitch
47,8
G/R 1/2“
G/R 11/2“
UNF 5/16“
0,9 0,91 1,0
1,5
1,06 1,34 1,4
1,81 2,3
Pitch mm