ST-1200 Line - Size 3 Studs

Material:
Stud: hardened steel
D-ring: hard music wire
Wing: carbon steel

Finish:
Stud, D-ring, and Wing: Zinc Trivalent Clear .0003 thick. Trivalent Chromate Clear with Sealer (RoHS Compliant)
Specification(s): ASTM-B-633, Type III, SC 2, Clear
Suffix: -Z3CT

Optional Stainless Steel:
Stud and Wing: 303 Stainless Steel
D-Ring: 400 series Stainless Steel

Optional Finishes: Change the plating suffix on the part number from "Z3CT" to the desired plating. See finishes pages.

Note: The size 3 stud is also available in a self ejecting configuration (type SE). Select this link for additional information.

Stud Dimensions

Slotted: 121J-3*-Z3CT		Wing: 121J-W3*-Z3CT
Click here for the Engineering Drawing 121J-3 Revision C		Click here for the Engineering Drawing 121J-W3 Revision C
Phillips: 121J-P3*-Z3CT		Hex Recess: 121J-H3*-Z3CT
Click here for the Engineering Drawing 121J-P3 Revision A		Click here for the Engineering Drawing 121J-H3 Revision A
Ring: 122J-R3*-Z3CT		Flush: 126J-3*-Z3CT
Click here for the Engineering Drawing 122J-R3 Revision D		Click here for the Engineering Drawing 126J-3 Revision B
Knurled: 1211-3*-Z3CT		Tamper Resist: 1230-3*-Z3CT
Click here for the Engineering Drawing 1211-3 Revision A

* is the "Stud Grip" from the table. For example, 121J-340-Z3CT is an oval head stud with a "Stud Grip" of 40.

The undercut is a part of the stud which is smaller in diameter than the stud shank. The undercut is located directly under the head. This decreased diameter is where the retainer fits to prevent the stud from coming out of the mounting hole.

The "J" designation in the 121J- part number indicates a Variable undercut. That is, the length of the undercut varies with the length of the stud. The Variable undercut is shown on this page.

The "N" designation in the 121N- part number indicates that the stud has no undercut. These were formerly referred to with a designation of "O" (i.e., AO and FO). The no undercut is shown on this link.

The absence of either the "J" or "N" designation indicates a Fixed size undercut. That is, the length of the undercut is the same for all stud lengths. The Fixed undercut is shown on this link.

Note: For all raised head styles, the "G" (Grip) and "U" (Undercut) dimensions are measured to the underside of the head. For the flush head style, the "G" (Grip) and "U" (Undercut) dimensions are measured to the top of the head.

Type SE

ST-1200 Line studs may be ordered as SE (Self Ejecting) assemblies. A stainless steel ejecting spring and a black plastic cup are sold attached to the stud. The SE ejection is partial, being limited by the length of the stud undercut not occupied by the cup, panel, and stud retainer. Ejection will normally be sufficient to give a visual cue of an unlocked stud. Also, ejecting spring tension holds an opened stud firmly, easing removal and replacement of vertical panels and panels with multiple fasteners.

Stud ejection = Dimension "U" (length of undercut) - total height of the cup (.090" [2.29 mm]), panel, and retainer. See stud selection tables for Dimension "U".

DFCI does not recommend using the SE option on any studs where Dimension "U" (length of undercut) is less than .300" (7.62mm). That is, on any stud less than -60 length.

Type SE ejecting stud assemblies are compatible with all receptacles in their size.

Sizing: When calculating the pileup for sizing an SE configuration, .090" (2.29 mm) must be added for the SE Cup.

Callout: Insert "SE" in front of the finish suffix. For example: Part Number 121J-360-SE-Z3CT.

For additional Self-Ejecting options, click this link.