Thread & Dimensions
A internal thread (Class 3B)
1/4-28 UNF
B external thread (Class 3A)
5/16-24 UNF
Ø max minor special
.2785
Ø C (+.008/-.002)
.252
D (+.015/-.000)
.095
F
.240
G (±.010)
.380
J (±1)
24
Through-hole preparation
Min. full THD depth .519; Min. full depth .415
Blind-hole preparation
Min. full THD depth .519; Min. full depth .415
Material & Finish
Material
17-4PH, Cond H1025 per AMS 5643
Finish
PASSIVATED per AMS 2700 & SFL coated per SAE AS5272, Type I
Temperature range
-110°/+650°F
Heat treat
RC 35-42
Magnetic
YES
Material note
Standard material code; no suffix added to the part number.
Crownserts is offering part CS428 as factory new.