SR-258L0003

Imperial Structural Locking Inserts

Locking Type / 17-4PH / Structural

Installed using the Crownserts Hand-Installation Tool:  CSTL428

SR-258L0003 repairs/reinforces 1/4-28 UNF imperial threads in Al/Mg or other non-ferrous materials; 17-4PH stainless. Tap hole .281 9/32; install with CSTL428. This is an old Anemo part. Please use CSL428.

We can offer you the part SR-258L0003 with Certificate of Quality, Certificate of Conformity and Certificate of Origin on request.

SR-258L0003 - Imperial Structural Locking Inserts
SR-258L0003 - Imperial Structural Locking Inserts
SR-258L0003 - Imperial Structural Locking Inserts
SR-258L0003 - Imperial Structural Locking Inserts
 How to install a Crownsert?
SR-258L0003 - Imperial Structural Locking Inserts
SR-258L0003 - Imperial Structural Locking Inserts
SR-258L0003 - Imperial Structural Locking Inserts

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
E .210
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
SR-258L0003 schematic

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.

Tooling & Preparation

Hand-Installation tool part number CSTL428
Step drill part number CSD0281
Tap through tool part number TTI0312
Blind tap tool part number TBI0312
Removal tool part number CSRT428
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