Part # UL-256-1CW, Miniature Self-Clinching Fasteners - Types U, UL, FE, FEO, FEOX, FEX

PEM® brand miniature fasteners fit into a minimal space and provide strong, reusable threads.

Types FE, FEO and UL are self-locking. Types FE and FEO thread locking torque performance is equivalent to applicable NASM25027 specifications. Type UL self-locking nuts meet locking torque requirements specified herein. Some sizes of FE, FEO, and UL can be ordered to NASM45938/7 specifications. Types FEX, FEOX and U have free-running class 2B/6H threads.

PEM miniature fasteners provide immediate visual indication when proper installation has been accomplished.

A strong, knurled collar, which is completely embedded in the sheet, guarantees against rotation of the fastener in the sheet. The torque-out resistance of the knurl greatly exceeds the torque that can be exerted by the selflocking feature.

When this collar is embedded in the sheet, the undercut cavity beneath the collar is filled with displaced sheet material thereby developing pushout resistance.

A dry-film lubricant applied to these fasteners provides the smooth, non-galling prevailing torque performance necessary for reliable locking and for reusability.

Unit of Measure

Specifications

Thread Size	N/A .086-56 (#2-56)
Thread Type	N/A Self-Locking
Thread Code	N/A 256
Shank Code¹	N/A 1
A (Shank) Max.	N/A .031 in
Sheet Thickness²	N/A .030 to .036 in
Hole Size in Sheet + .003 - .000	N/A .144 in
C + .000 - .005	N/A .144 in
D Max.	N/A .106 in
E ± .005	N/A .160 in
T + .015 -.000	N/A .065 in
Min. Dist. Hole C/L to Edge³	N/A .110 in
Max. Hole in Attached Parts	N/A .106 in
For Use in Sheet Hardness⁴	N/A HRB 70 / HB 125 or Less
Thread Specification	N/A Internal, MIL-S-8879, UNJ-3B
Fastener Material	N/A 300 Series Stainless Steel
Standard Finish	N/A Passivated Plus Clear Dry-film Lubricant
CAD Supplier	N/A PennEngineering® (PEM®)
Inventory	N/A {0}

¹ Shank code applicable only to Types U and UL fasteners.
² In applications between the sheet thicknesses for your thread size, see last paragraph of installation data on page FE-6. Knurled collar may fracture if fastener is used in sheets thicker than the specified range and the screw is tightened beyond maximum
³ To minimize sheet distortion and maximize product performance, use a centerline-to-edge value greater or equal to the value specified.
⁴ HRB - Hardness Rockwell “B” Scale. HB - Hardness Brinell.

Specifications

Thread Size

Thread Type

Thread Code

A (Shank) Max.

Hole Size in Sheet + .003 - .000

C + .000 - .005

D Max.

E ± .005

T + .015 -.000

Max. Hole in Attached Parts

Thread Specification

Fastener Material

Standard Finish

CAD Supplier

Inventory