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CS428AD

Imperial Structural Standard Crownserts

CS Series / Standard Type / AD / Structural

Installed using the Crownserts Hand-Installation Tool:  CST428

CS428AD reinforces or repairs 1/4-28 UNF imperial threads in aluminium, magnesium or other non-ferrous materials. 4130 alloy steel for high mechanical strength, with .281 9/32 tap-hole guidance and CST428 hand installation tooling.

Crownserts can offer you the part CS428AD with Certificate of Quality, Certificate of Conformity and Certificate of Origin on request.

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
CS428AD schematic

Material & Finish

Material Alloy Steel 4130 per AMS 6370
Finish Cadmium Plated per AMS-QQ-P-416 Type 2, Class 3 & SFL per SAE AS5272
Temperature range Up to 450+°F
Heat treat RC 25-34
Magnetic YES

Tooling & Preparation

Hand-installation tool part number CST428
Step drill part number CSD0281
Tap through tool part number TTI0312
Blind tap tool part number TBI0312
Removal tool part number CSRT428

Crownserts is offering part CS428AD as factory new.