FLEXLOC® Locknuts
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Aluminum Self-Locking Nuts
Aluminum Self-Locking NutsThe FLEXLOC® locknut is the classic self-locking nut. Its one piece, all metal construction stands up under extreme temperatures, vibration, and shock. Because a FLEXLOC® locknut has no nylon insert, it consistently provides better tensile strength than the leading “two-element” locknuts and is ideal for elevated temperature environments.
The real secret of the FLEXLOC® design, however, is the slotted locking feature. As the bolt engages the locking feature, the slotted section expands, initiating the locking action. This expansion lifts the nut upward, causing the threads to bear against the lower surface of the bolt threads. Once fully engaged, each FLEXLOC® thread provides a load-carrying capacity resulting in a lower more uniform distribution of stress per thread. This locking feature and the FLEXLOC® locknut’s all-metal construction combine to create superior vibration resistance.
The FLEXLOC® full height locknut provides up to 19% more tensile strength than the leading nylon insert (two-element) locknut and as much as 26% more strength than a competitive all-metal locknut of equal size.
The FLEXLOC® thin height locknut provides virtually twice as much tensile strength as the leading nylon insert locknut.
The FLEXLOC® locknut has imitators but no equal. For durability, strength, and overall value, it is the premier industrial locknut. Below you will find a brief overview of the FLEXLOC® locknut product line offered by Unbrako through industrial distribution for use in industrial applications. Each is the product of advanced engineering, sophisticated manufacturing systems, and rigorous quality control standards. Download our Brochure.
No matter your requirements, please do not hesitate to contact us as your locknut & aluminum self-locking nut distributor.
Sizes & Specifications Chart
| TYPES | APPLICATIONS & FEATURES | MATERIALS | STANDARD SIZES | |
|---|---|---|---|---|
| UNC | UNF | |||
|
Full Height Heavy-Duty Steel
|
One-piece, all-metal locknut. Full size, heavy-duty hex for maximum strength and wrenchability.
|
Steel Stainless Steel Brass Aluminum
|
1/4″-2 1/2 | |
|
Full Height Light Hex
|
Full height, light hex for better wrench clearance and lighter weight. Both, for a broad range of industrial and commercial applications.
|
Steel Stainless Steel Brass Aluminum
|
2 – 1″ | 2 – 2 1/2″ |
|
Thin Height Heavy-Duty Hex
|
Exceptional strength in low height nut because all threads are load-carrying. Combines ruggedness with space savings. Also available in light hex with 20% less weight and 30% less height for compact or “tight” assemblies.
|
Steel Stainless Steel Brass Aluminum
|
1/4″-1 1/2″ | |
|
Thin Height Light Hex
|
Steel stainless Steel Brass Aluminum
|
#6 – 1″ | 6 – 2″ | |
|
Microsize
|
For miniature threaded joints in small assemblies. Uses triangular displacement of the threads for positive locking power and optimum strength to weight ratio. Controlled locking torques provide accurate preloading of bolts, stufs, and screws. Ideal for instruments, radar, and electronic equipment.
|
Steel Stainless Steel Brass Aluminum
|
#0 – #4 | 0 – #4 |
Available In-Stock Products
All Available Products for Order
SPS FLEXLOC® NUT
HEAVY HEX–FULL HEIGHT
STEEL–PLAIN FINISH
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 20FAC-420 | 124476 | 1/4 |
| 20FA-518 | 114402 | 5/16 |
| 20FA-616 | 111622 | 3/8 |
| 20FA-714 | 114022 | 7/16 |
| 20FA-813 | 106371 | 1/2 |
| 30FA-1011 | 119957 | 5/8 |
| 30FA-1210 | 118123 | 3/4 |
| 30FA-1409 | 117351 | 7/8 |
| 30FA-1608 | 117482 | 1 |
SPS FLEXLOC® NUT
HEAVY HEX–FULL HEIGHT
STEEL–CADMIUM PLATED
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 21FAC-420 | 124486 | 1/4 |
| 21FA-518 | 117328 | 5/16 |
| 21FA-616 | 111688 | 3/8 |
| 21FA-714 | 114087 | 7/16 |
| 21FA-813 | 106435 | 1/2 |
| 31FA-1011 | 119990 | 5/8 |
| 31FA-1210 | 119580 | 3/4 |
| 31FA-1409 | 117385 | 7/8 |
| 31FA-1608 | 117515 | 1 |
SPS FLEXLOC® NUT
HEAVY HEX–FULL HEIGHT
CORROSION RESISTANT STEEL–PLAIN FINISH
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 50FAC-420 | 123561 | 1/4 |
| 50FA-518 | 113620 | 5/16 |
| 50FA-616 | 115516 | 3/8 |
| 50FA-714 | 115104 | 7/16 |
| 50FA-813 | 117237 | 1/2 |
| 50FA-1011 | 116974 | 5/8 |
| 50FA-1210 | 118969 | 3/4 |
| 50FA-1409 | 119101 | 7/8 |
| 50FA-1608 | 113165 | 1 |
SPS FLEXLOC® NUT
LIGHT HEX–FULL HEIGHT
STEEL–PLAIN FINISH
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 20FA-256 | 120704 | #2 |
| 20FA-440 | 113704 | #4 |
| 20FA-632 | 114572 | #6 |
| 20FA-832 | 105717 | #8 |
| 20FA-1024 | 105795 | #10 |
| 20FC-1032 | 109078 | #10 |
| 20FA-420 | 109304 | 1/4 |
| 20FC-428 | 108726 | 1/4 |
| 20FAF-518 | 118634 | 5/16 |
| 20FC-524 | 117459 | 5/16 |
| 20FAF-616 | 115899 | 3/8 |
| 20FC-624 | 109641 | 3/8 |
| 20FAF-714 | 120467 | 7/16 |
| 20FC-720 | 106112 | 7/16 |
| 20FAF-813 | 120533 | 1/2 |
| 20FC-820 | 116788 | 1/2 |
| 30FAF-1011 | 120664 | 5/8 |
| 30FC-1018 | 120089 | 5/8 |
| 30FAF-1210 | 118754 | 3/4 |
| 30FC-1216 | 117286 | 3/4 |
| 30FAF-1409 | 120478 | 7/8 |
| 30FC-1414 | 117417 | 7/8 |
| 30FAF-1608 | 120544 | 1 |
| 30FC-1612 | 125896 | 1 |
| 30FC-1614 | 117547 | 1 |
| 30FC-1812 | 1-1/8 | |
| 30FC-2012 | 1-1/4 | |
| 30FC-2212 | 1-3/8 | |
| 30FC-2412 | 1-1/2 |
SPS FLEXLOC® NUT
LIGHT HEX–FULL HEIGHT
STEEL–CADMIUM PLATED
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 21FA-256 | 108930 | #2 |
| 21FA-440 | 138001 | #4 |
| 21FA-632 | 138004 | #6 |
| 21FA-832 | 138007 | #8 |
| 21FA-1024 | 138010 | #10 |
| 21FC-1032 | 138012 | #10 |
| 21FA-420 | 108591 | 1/4 |
| 21FC-428 | 138014 | 1/4 |
| 21FAF-518 | 138167 | 5/16 |
| 21FC-524 | 138016 | 5/16 |
| 21FAF-616 | 138168 | 3/8 |
| 21FC-624 | 138018 | 3/8 |
| 21FAF-714 | 138169 | 7/16 |
| 21FC-720 | 138021 | 7/16 |
| 21FAF-813 | 138170 | 1/2 |
| 21FC-820 | 138022 | 1/2 |
| 31FAF-1011 | 138171 | 5/8 |
| 31FC-1018 | 138026 | 5/8 |
| 31FAF-1210 | 138172 | 3/4 |
| 31FC-1216 | 138028 | 3/4 |
| 31FAF-1409 | 138173 | 7/8 |
| 31FC-1414 | 138030 | 7/8 |
| 31FAF-1608 | 138174 | 1 |
| 31FC-1612 | 138032 | 1 |
| 31FC-1614 | 138033 | 1 |
| 31FC-1812 | 1-1/8 | |
| 31FC-2012 | 1-1/4 | |
| 31FC-2212 | 1-3/8 | |
| 31FC-2412 | 1-1/2 |
SPS FLEXLOC® NUT
LIGHT HEX–FULL HEIGHT
CORROSION RESISTANT STEEL–PLAIN FINISH
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 50FA-256 | 126236 | #2 |
| 50FA-440 | 106189 | #4 |
| 50FA-632 | 106286 | #6 |
| 50FA-832 | 106383 | #8 |
| 50FA-1024 | 106480 | #10 |
| 50FC-1032 | 106512 | #10 |
| 50FA-420 | 113491 | 1/4 |
| 50FC-428 | 113556 | 1/4 |
| 50FAF-518 | 124176 | 5/16 |
| 50FC-524 | 106571 | 5/16 |
| 50FAF-616 | 124128 | 3/8 |
| 50FC-624 | 115581 | 3/8 |
| 50FC-720 | 115138 | 7/16 |
| 50FAF-813 | 123868 | 1/2 |
| 50FC-820 | 105834 | 1/2 |
| 50FC-918 | 105898 | 9/16 |
| 50FC-1018 | 117042 | 5/8 |
| 50FC-1216 | 119034 | 3/4 |
| 50FC-1414 | 119134 | 7/8 |
| 50FC-1612 | 611389 | 1 |
| 50FC-1614 | 113229 | 1 |
SPS FLEXLOC® NUT
HEAVY HEX–THIN HEIGHT
STEEL–PLAIN FINISH
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 20FKC-420 | 125582 | 1/4 |
| 20FK-518 | 105047 | 5/16 |
| 20FK-616 | 102647 | 3/8 |
| 20FK-714 | 118496 | 7/16 |
| 20FK-813 | 118627 | 1/2 |
| 30FK-1011 | 102612 | 5/8 |
| 30FK-1210 | 102414 | 3/4 |
| 30FK-1409 | 110920 | 7/8 |
| 30FK-1608 | 111616 | 1 |
| 30FK-2007 | 119709 | 1-1/4 |
| 30FK-2406 | 106758 | 1-1/2 |
SPS FLEXLOC® NUT
HEAVY HEX–THIN HEIGHT
STEEL–CADMIUM PLATED
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 21FKC-420 | 125737 | 1/4 |
| 21FK-518 | 110514 | 5/16 |
| 21FK-616 | 107329 | 3/8 |
| 21FK-714 | 118528 | 7/16 |
| 21FK-813 | 116307 | 1/2 |
| 31FK-1011 | 102645 | 5/8 |
| 31FK-1210 | 102481 | 3/4 |
| 31FK-1409 | 120769 | 7/8 |
| 31FK-1608 | 111649 | 1 |
| 31FK-2007 | 119742 | 1-1/4 |
| 31FK-2406 | 106790 | 1-1/2 |
SPS FLEXLOC® NUT
HEAVY HEX–THIN HEIGHT
CORROSION RESISTANT STEEL–PLAIN FINISH
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 50FKC-420 | 125668 | 1/4 |
| 50FK-518 | 109565 | 5/16 |
| 50FK-616 | 103911 | 3/8 |
| 50FK-813 | 115263 | 1/2 |
| 50FK-1011 | 102368 | 5/8 |
| 50FK-1210 | 111451 | 3/4 |
| 50FK-1409 | 111549 | 7/8 |
| 50FK-1608 | 622952 | 1 |
SPS FLEXLOC® NUT
LIGHT HEX–THIN HEIGHT
STEEL–PLAIN FINISH
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 20FK-632 | 120662 | #6 |
| 20FK-832 | 105926 | #8 |
| 20FK-1024 | 106087 | #10 |
| 20FK-1032 | 117188 | #10 |
| 20FK-420 | 104355 | 1/4 |
| 20FK-428 | 103790 | 1/4 |
| 20FKF-518 | 102393 | 5/16 |
| 20FK-524 | 116374 | 5/16 |
| 20FKF-616 | 117936 | 3/8 |
| 20FK-624 | 107393 | 3/8 |
| 20FK-720 | 118562 | 7/16 |
| 20FKF-813 | 118066 | 1/2 |
| 20FK-820 | 116405 | 1/2 |
| 30FK-918 | 115652 | 9/16 |
| 30FKF-1011 | 114067 | 5/8 |
| 30FK-1018 | 102679 | 5/8 |
| 30FKF-1210 | 117649 | 3/4 |
| 30FK-1216 | 110789 | 3/4 |
| 30FK-1414 | 111311 | 7/8 |
| 30FKF-1608 | 130555 | 1 |
| 30FK-1612 | 124241 | 1 |
| 30FK-1614 | 111682 | 1 |
| 30FK-1812 | 1-1/8 | |
| 30FK-2012 | 1-1/4 | |
| 30FK-2212 | 1-3/8 | |
| 30FK-2412 | 1-1/2 |
SPS FLEXLOC® NUT
LIGHT HEX–THIN HEIGHT
STEEL–CADMIUM PLATED
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 21FK-632 | 138039 | #6 |
| 21FK-832 | 138042 | #8 |
| 21FK-1024 | 138045 | #10 |
| 21FK-1032 | 138046 | #10 |
| 21FK-420 | 110480 | 1/4 |
| 21FK-428 | 138048 | 1/4 |
| 21FKF-518 | 111444 | 5/16 |
| 21FK-524 | 138050 | 5/16 |
| 21FKF-616 | 117968 | 3/8 |
| 21FK-624 | 138052 | 3/8 |
| 21FK-720 | 138054 | 7/16 |
| 21FKF-813 | 114035 | 1/2 |
| 21FK-820 | 110543 | 1/2 |
| 31FK-918 | 115685 | 9/16 |
| 31FKF-1011 | 114100 | 5/8 |
| 31FK-1018 | 102711 | 5/8 |
| 31FKF-1210 | 106125 | 3/4 |
| 31FK-1216 | 138176 | 3/4 |
| 31FK-1414 | 138057 | 7/8 |
| 31FKF-1608 | 124303 | 1 |
| 31FK-1614 | 138059 | 1 |
| 31FK-1612 | 138177 | 1 |
| 31FK-1812 | 138061 | 1-1/8 |
| 31FK-2012 | 138062 | 1-1/4 |
| 31FK-2212 | 106726 | 1-3/8 |
| 31FK-2412 | 113671 | 1-1/2 |
SPS FLEXLOC® NUT
LIGHT HEX–THIN HEIGHT
CORROSION RESISTANT STEEL–PLAIN FINISH
| PART NUMBER | PRODUCT NUMBER | SIZE |
| 50FK-632 | 114856 | #6 |
| 50FK-832 | 102528 | #8 |
| 50FK-1024 | 115371 | #10 |
| 50FK-1032 | 115402 | #10 |
| 50FK-420 | 103406 | 1/4 |
| 50FK-428 | 103471 | 1/4 |
| 50FKF-518 | 123898 | 5/16 |
| 50FK-524 | 114951 | 5/16 |
| 50FKF-616 | 123515 | 3/8 |
| 50FK-624 | 103273 | 3/8 |
| 50FK-720 | 103372 | 7/14 |
| 50FKF-813 | 124506 | 1/2 |
| 50FK-820 | 115295 | 1/2 |
| 50FK-918 | 102301 | 9/16 |
| 50FK-1018 | 102401 | 5/8 |
| 50FK-1216 | 111484 | 3/4 |
MICROSIZE LOCKNUTS
STEEL–PLAIN FINISH
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 30FM-256 | 109239 | #2 |
| 30FM-264 | 103867 | #2 |
| 30FM-440 | 107442 | #4 |
MICROSIZE LOCKNUTS
STEEL–CADMIUM PLATE
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 32FM-256 | 105802 | #2 |
| 32FM-264 | 107282 | #2 |
| 32FM-440 | 118513 | #4 |
MICROSIZE LOCKNUTS
CORROSION RESISTANT STEEL–PLAIN FINISH
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 50FM-080 | 104949 | #0 |
| 50FM-256 | 116248 | #2 |
| 50FM-348 | 115626 | #3 |
| 50FM-440 | 107363 | #4 |
LARGE SIZE FLEXLOC® NUTS
FULL HEIGHT
STEEL–PLAIN FINISH
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 30FN-1807 | 117614 | 1-1/8 |
| 30FN-2007 | 114986 | 1-1/4 |
| 30FN-2206 | 113117 | 1-3/8 |
| 30FN-2406 | 107657 | 1-1/2 |
| 30FN-2605 | 104360 | 1-5/8 |
| 30FN-2805 | 102220 | 1-3/4 |
| 30FN-3204 | 120531 | 2 |
| 30FO-1808 | 102067 | 1-1/8 |
| 30FO-2008 | 116274 | 1-1/4 |
| 30FO-2208 | 116306 | 1-3/8 |
| 30FO-2408 | 116339 | 1-1/2 |
| 30FO-2608 | 111040 | 1-5/8 |
| 30FO-2808 | 111073 | 1-3/4 |
| 30FO-3208 | 104725 | 2 |
| 30FO-3608 | 2.25 |
LARGE SIZE FLEXLOC® NUTS
FULL HEIGHT
STEEL–CADMIUM PLATED
| PART NUMBER | PRODUCT NUMBER | SIZE |
|---|---|---|
| 31FN-1807 | 109442 | 1-1/8 |
| 31FN-2007 | 115018 | 1-1/4 |
| 31FN-2206 | 111905 | 1-3/8 |
| 31FN-2406 | 107689 | 1-1/2 |
| 31FN-2605 | 114846 | 1-5/8 |
| 31FN-2805 | 104407 | 1-3/4 |
| 31FN-3204 | 120597 | 2 |