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CS420D

Imperial Structural Standard Crownserts

CS Series / Standard Type / D / Structural

Installed using the Crownserts Hand-Installation Tool:  CST420

CS420D reinforces or repairs 1/4-20 UNC 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 CST420 hand installation tooling.

Crownserts can offer you the part CS420D with Certificate of Quality, Certificate of Conformity and Certificate of Origin on request.

Thread & Dimensions

A internal thread (Class 3B) 1/4-20 UNC
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
CS420D 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 CST420
Step drill part number CSD0281
Tap through tool part number TTI0312
Blind tap tool part number TBI0312

Crownserts is offering part CS420D as factory new.