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When selecting finishes, select the RoHS compliant finishes. They are better for the environment and less expensive!
 

ST-1200 Line - Size 7 Studs
Standard Variable Length Undercut

The information on the ST-1200 Size 7 products are provided for existing applications. For new applications, please use the Size 65 products.

Standard Materials:
Studs: hardened steel
D-rings: hard music wire
Wings: carbon steel

Finish: 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:
303 Stainless Steel studs,
400 series Stainless Steel D-rings,
300 series Stainless Steel wings

Optional Finishes: Change the finish suffix from Z3CT to the desired finish from the table. See finishes page.

Stud Dimensions

SLOTTED: 121J-7*-Z3CT FLUSH: 126J-7*-Z3CT
Slotted Head Stud Picture

Click here for the Engineering Drawing
121J-7 Revision A

 Slotted Head Stud Dimension Drawing Flush Head Stud Picture Flush Head Stud Dimension Drawing
WING: 121J-W7*-Z3CT PHILLIPS: 121J-P7*-Z3CT
Wing Head Stud Picture

Click here for the Engineering Drawing
121J-W7 Revision A

 Wing Head Stud Dimension Drawing Phillips Recess Stud Picture Phillips Recess Stud Dimension Drawing
HEX: 121J-H7*-Z3CT KNURLED: 1211-7*-Z3CT
Hex Recess Head Stud Picture Hex Recess Head Stud Dimension Drawing Knurled Head Stud Picture Knurled Head Stud Dimension Drawing
RING: 122J-R7*-Z3CT TAMPER RESIST: 1230-7*-Z3CT
Ring Head Stud Picture

Click here for the Engineering Drawing
122J-R7 Revision B

 Ring Head Stud Dimension Drawing Tamper Resist Head Stud Picture Tamper Resist Stud Dimension Drawing

* is the "Stud Grip" from the tables.  For example, 121J-740 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.

Stud Grip Undercut Dimension (U) Grip Length (G)
All Except Flush Flush Head Only
(inch) (mm) (inch) (mm) (inch) (mm)
35 .175 4.45 --- --- .350 8.89
40 .190 4.83 --- --- .400 10.16
50 .250 6.35 .250 6.35 .500 12.70
60 .300 7.62 .300 7.62 .600 15.24
70 .350 8.89 .350 8.89 .700 17.78
80 .450 11.43 .450 11.43 .800 20.32
90 .550 13.97 .550 13.97 .900 22.86
100 .650 16.51 .650 16.51 1.000 25.40
110 .650 16.51 .650 16.51 1.100 27.94
120 .650 16.51 .650 16.51 1.200 30.48

Note: When our existing supply of Cadmium plated parts is exhausted, DFCI Solutions, Inc will no longer offer Cadmium plating as an option.

In place of the Cadmium plating, we recommend:

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

Black: Zinc Trivalent Black .0003 thick. Trivalent Chromate Black Dye with Sealer (RoHS Compliant)
Specification(s): ASTM-B-633, Type II, SC 2, Black
Suffix: -Z3BT

Yellow: Zinc Trivalent Yellow .0003 thick, Trivalent Chromate Yellow Dye with Sealer

We recommend the Z3CT finish instead of the Z3YT finish. The Z3CT finish is much more cost effective and provides the same salt spray benefits as the Z3YT finish. (RoHS Compliant)
Specification(s): ASTM-B-633, Type II, SC 2, Yellow
Suffix: -Z3YT

The colored finishes offer no advantage over the clear other than the color, and they are more expensive.