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Locking and Non-locking Threads
These fasteners provide load-bearing threads in thin sheets and permit up to .030” adjustment for mating hole misalignment.

The self-clinching feature offers fast and simple assembly. The fasteners are squeezed into prepared holes using any standard press. The sheet remains flush on one side, and the fastener is permanently locked in place.

Extra strength and support in assembly is obtained by the threads of the floating nut extending fully into the retainer shank (a unique PEM feature). A self-locking version of the fastener is also offered. Thread locking torque performance is equivalent to applicable NASM25027 specifications.

Non-locking Type A4 and self-locking Type LA4 fasteners provide load-bearing threads in stainless steel sheets as thin as .038” with hardness up to HRB 88 on the Rockwell “B” scale.

Many PEM Type AS and AC self-clinching floating fasteners correspond to sizes in US NASM45938/11 specifications. Check our web site for a complete Military Specification and National Aerospace Standards Reference Guide (Bulletin NASM).
Floating-Nuts-non-locking
Floating Self-Clinching Fasteners - Types A4, AS, AC 2
Unit of Measure
Items Floating-Nuts-non-locking
A4-440-1
Floating Self-Clinching Fasteners A4, AS, AC - Unified
Floating-Nuts-non-locking
A4-632-1
Floating Self-Clinching Fasteners A4, AS, AC - Unified
Floating-Nuts-non-locking
A4-832-1
Floating Self-Clinching Fasteners A4, AS, AC - Unified
Floating-Nuts-non-locking
A4-032-1
Floating Self-Clinching Fasteners A4, AS, AC - Unified
Thread Size N/A .112-40 (#4-40) N/A .138-32 (#6-32) N/A .164-32 (#8-32) N/A .190-32 (#10-32)
Thread Type N/A Non-Locking a1369_1.jpg
Thread Code N/A 440 N/A 632 N/A 832 N/A 032
Shank Code1 N/A 1
A (Shank) Max. N/A 0.038 in a1367_1.jpg
Min. Sheet Thickness N/A .038 in
Hole Size in Sheet + .003 - .000 N/A .290 in N/A .328 in N/A .368 in N/A .406 in
C Max. N/A .289 in N/A .327 in N/A .367 in N/A .405 in
D Max. N/A .290 in N/A .335 in N/A .365 in N/A .405 in
E ± .015 N/A .360 in N/A .390 in N/A .440 in N/A .470 in
T1 Max. N/A .130 in N/A .130 in N/A .130 in N/A .170 in
Min. Dist. Hole C/L to Edge2 N/A .300 in N/A .320 in N/A .34 in N/A .360 in
Float N/A .015” minimum, in all directions from center, .030” total
Fastener Material N/A 400 Series Stainless Steel
Fastener Materials - Retainer N/A 400 Series Stainless Steel
Fastener Materials - Nut N/A 300 Series Stainless Steel
Standard Finish - Retainer & Nut N/A Passivated and/or tested per ASTM A380
For Use in Sheet Hardness3 N/A HRB 88 / HB 183 or Less
Thread Specification N/A Internal, ANSI B1.1, 2B
CAD Supplier N/A PennEngineering® (PEM®)
Inventory N/A {0} N/A {0} N/A {0} N/A {0}
  • 1 Other shank and screw lengths available.
  • 2 To minimize sheet distortion and maximize product performance, use a centerline-to-edge value greater or equal to the value specified.
  • 3 HRB - Hardness Rockwell “B” Scale. HB - Hardness Brinell.