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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. Ty
Unit of Measure

Specifications

Thread Size

.250-28 (1/4-28)

Thread Type

Non-Locking

Thread Code

0428

A (Shank) Max.

.060 in a1387.jpg
Sheet Thickness1 .059 to .070 in

Hole Size in Sheet + .003 - .000

.344 in

C + .000 - .005

.343 in

D Max.

.318 in

E ± .005

.384 in

T + .015 -.000

.120 in

Min. Dist. Hole C/L to Edge

.28 in

Max. Hole in Attached Parts

.270 in
For Use in Sheet Hardness2 HRB 70 / HB 125 or Less

Thread Specification

Internal, ANSI B1.1, 2B

Fastener Material

300 Series Stainless Steel

Standard Finish

Passivated and/or tested per ASTM A380

CAD Supplier

PennEngineering® (PEM®)
  • 1 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 tightening torque.
  • 2 HRB - Hardness Rockwell “B” Scale. HB - Hardness Brinell.