from
FULL HEIGHT
THIN HEIGHT
FAX
(630) 628-5330
(630) 628-5331

Locknut Technology Inc. warrants that these products conform to industry standards specified herein and will be free from defects in materials and workmanship. THIS WARRANTY IS EXPRESSLY GIVEN IN LIEU OF ANY AND ALL OTHER
EXPRESS OR IMPLIED WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE, AND IN LIEU OF ANY OTHER OBLIGATION ON THE PART OF LOCKNUT TECHNOLOGIES INC.
Locknut Technologies Inc. will, at its option, repair or replace free of charge (excluding all shipping and handling costs) any products which have not been subject to misuse, abuse, or modification and which in its sole determination were not manufactured in compliance with the warranty given above.
THE REMEDY PROVIDED FOR HEREIN SHALL BE THE EXCLUSIVE REMEDY FOR ANY BREACH OF WARRANTY OR ANY
CLAIM ARISING IN ANY WAY OUT OF THE MANUFACTURE, SALE, OR USE OF THESE PRODUCTS. In no event shall
Locknut Technologies Inc. be liable for consequential, incidental or any other damages of any nature whatsoever except those specifically provided herein for any breach of warranty or any claim arising in any way of the manufacture, sale, or use of these products.
351 S. Lombard Avenue
Addison, Illinois 60101
Phone: (630) 628-5330
Fax: (630) 628-5331
SALES
Email: robert.motz@locknuttechnology.com
Products in this catalog have been designed and manufactured to perform to specific standards to meet applications in industrial applications. They are not designed to meet specific standards for the Military/Aerospace markets, although interchangeability may exist.

®
Full Height Light Hex
Page 2
Page 3
Page 4
Thread # 2 to # 10
Thread # 12 to # 1/2"
Thread # 9/16" to # 1"
Thin Height Light Hex
Page 5
Page 6
Page 7
Page 8
Thread # 6 to # 5/16"
Thread # 3/8" to # 3/4"
Thread # 7/8" to # 1 1/2"
Technical Information
Locknut Technology has been supplying industry with top quality, cost efficient locknuts since 1995. Our technical leadership capabilities in manufacturing and the consistency and dependability of our products allows us to offer our customers unsurpassed quality, value and on-time delivery.
All of our locknuts incorporate a precision thread deflection process using a state-of-the-art manufacturing equipment. Our product is produced to
IFI specifications 100/107 as well as prevailing torque per NASM 25027.
Locknut Technology is operating under ISO9001-2000 registration to meet world class quality standards.
Every part is fully traceable with lot number identification on cartons packing slip and invoices. Our in-house lab is fully equipped to perform any of your certification requirements, including Level III PPAPS.
Quality is not inspected in, but built into every product using state-of-the-art production equipment. This allows us to offer special high or low torque requirements, as well as the fastest turnaround time in the industry.
Locknut Technology has extensive experience manufacturing prevailing-torque all-metal locknuts.
Self-locking nuts are our only business. So, for your best value, trust our manufacturing capability, dependability and consistency of products.
Our registered product trademark is your assurance of full lot traceability and full performance satisfaction.
We shall continue to manufacture only the best quality and greatest value. We shall continue to make our products readily and dependably available, and we shall continue to dedicate ourselves to helpful service.
L
LOCKNUT TECHNOLOGY, INC.
Registered Identification Symbol
1

FLEXTOP ® LOCKNUTS
FULL HEIGHT LIGHT HEX
NOMINAL
THREAD
SIZE
LOCKNUT
TECHNOLOGY
PART NO.,
#2
#3
#4
#5
#6
#8
#10
MATERIAL
AND
FINISH
THREAD
PROOF
LOAD
LB.
W
WIDTH ACROSS
FLATS
MAX. MIN.
C
WIDTH
H S B
ACROSS THICKNESS HEIGHT OF BEARING
CORNERS MAX.
HEX. MIN DIA. MIN.
REF.
WEIGHT
LB./100
APPROX.
LTS-448S
LTS-448SV
LTS-540
LTS-540C
LTS-540S
LTS-540SV
LTS-544
LTS-544C
LTS-544S
LTS-544SV
LTS-632
LTS-632C
LTS-256
LTS-256C
LTS-256S
LTS-256SV
LTS-348
LTS-348C
LTS-348S
LTS-348SV
LTS-440
LTS-440C
LTS-440S
LTS-440SV
LTS-448
LTS-448C
LTS-632S
LTS-632SV
LTS-640
LTS-640C
LTS-640S
LTS-640SV
LTS-832
LTS-832C
LTS-832S
LTS-832SV
LTS-836
LTS-836C
Stainless - Plain
Stainless - Silver
Steel- Plain
Steel - Cadmium
Stainless -Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
LTS-836S
LTS-836SV
LTS-1024
LTS-1024C
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
LTS-1024S Stainless - Plain
LTS-1024SV Stainless - Silver
LTS-1032
LTS-1032C
Steel - Plain
Steel - Cadmium
LTS-1032S Stainless - Plain
LTS-1032SV Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
.086 - 56 UNC-3B
.099 - 48 UNC-3B
.112 - 40 UNC-3B
.112 - 48 UNF-3B
.125 - 40 UNC-3B
.125 - 44 UNF-3B
.138-32 UNC-3B
.138 - 40 UNF-3B
.164-32 UNC-3B
.164 - 36 UNF-3B
.190-24 UNC-3B
.190 - 32 UNF-3B
650
865
1,080 .251
1,190
1,400
1,450
1,620
1,890
2,510
2,620
3,120
3,590
.251
.251
.251
.251
.251
.313
.313
.345
.345
.376
.376
.243
.243
.243
.243
.243
.243
.305
.305
.336
.336
.367
.367
.277
.243
.277
.277
.277
.277
.347
.347
.383
.383
.419
.419
.155
.155
.155
.155
.155
.155
.180
.180
.243
.243
.243
.243
.050
.050
.050
.050
.052
.052
.075
.075
.105
.105
.085
.085
.243
.277
.243
.243
.243
.243
.305
.305
.336
.336
.367
.367
.15
.15
.14
.14
.13
.13
.27
.27
.46
.46
.53
.53
2

FLEXTOP ® LOCKNUTS
FULL HEIGHT LIGHT HEX
NOMINAL
THREAD
SIZE
LOCKNUT
TECHNOLOGY
PART NO.
MATERIAL
AND
FINISH
THREAD
PROOF
LOAD
LB.
W
WIDTH ACROSS
FLATS
MAX. MIN.
C
WIDTH
H S B
ACROSS THICKNESS HEIGHT OF BEARING
CORNERS MAX.
HEX. MIN DIA. MIN.
REF.
WEIGHT
LB./100
APPROX.
#12
1/4"
5/16"
3/8"
7/16"
1/2"
LTS-524
LTS-524C
LTS-524S
LTS-524SV
LTS-616
LTS-616C
LTS-616S
LTS-616SV
LTS-624
LTS-624C
LTS-624S
LTS-624SV
LTS-714
LTS-714C
LTS-714S
LTS-714SV
LTS-720
LTS-720C
LTS-720S
LTS-720SV
LTS-813
LTS-813C
LTS-813S
LTS-813SV
LTS-820
LTS-820C
LTS-820S
LTS-820SV
LTS-1224
LTS-1224C
LTS-1224S
Steel - Plain
Steel - Cadmium
Stainless - Plain
LTS-1224SV Stainless - Silver
LTS-1228 Steel - Plain
LTS-1228C
LTS-1228S
Steel - Cadmium
Stainless - Plain
LTS-1228SV Stainless - Silver
LTS-420
LTS-420C
LTS-420S
LTS-420SV
LTS-428
LTS-428C
LTS-428S
LTS-428SV
LTS-518
LTS-518C
LTS-518S
LTS-518SV
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
.216-24 UNC-3B
.216 - 28 UNF-3B
.250-20 UNC-2B
.250 - 28 UNF-3B
.312-18 UNC-2B
.312 - 24 UNF-3B
.375-16 UNC-2B
.375 - 24 UNF-3B
.437-14 UNC-2B
.437 - 20 UNF-3B
.500-13 UNC-2B
.500 - 20 UNF-3B
4,350
4,630
5,730
6,550
9,600
9,950
13,800
14,500
14,900
15,450
22,000
23,800
.439
.439
.439
.439
.502
.502
.564
.564
.627
.627
.752
.752
.430
.430
.430
.430
.492
.492
.553
.553
.616
.616
.741
.741
.491
.491
.491
.491
.561
.561
.631
.631
.703
.703
.846
.846
.290
.290
.290
.320
.353
.353
.462
.462
.462
.462
.602
.602
.122
.122
.122
.135
.150
.150
.210
.210
.210
.210
.285
.285
.430
.430
.430
.430
.492
.492
.553
.553
.616
.616
.741
.741
.89
.89
.80
.90
1.30
1.30
1.95
1.95
2.30
2.30
4.35
4.35
3

FLEXTOP ® LOCKNUTS
FULL HEIGHT LIGHT HEX
NOMINAL
THREAD
SIZE
LOCKNUT
TECHNOLOGY
PART NO.
MATERIAL
AND
FINISH
THREAD
PROOF
LOAD
LB.
W
WIDTH ACROSS
FLATS
MAX. MIN.
C
WIDTH
H S B
ACROSS THICKNESS HEIGHT OF BEARING
CORNERS MAX.
HEX. MIN DIA. MIN.
REF.
WEIGHT
LB./100
APPROX.
9/16"
5/8"
3/4"
7/8"
1"
LTS-912
LTS-912C
LTS-912S
LTS-912SV
LTS-918
LTS-918C
LTS-918S
LTS-918SV
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
LTS-1011
LTS-1011C
Steel - Plain
Steel - Cadmium
LTS-1011S Stainless - Plain
LTS-1011SV Stainless - Silver
LTS-1018
LTS-1018C
LTS-1018S
Steel - Plain
Steel - Cadmium
Stainless - Plain
LTS-1018SV Stainless - Silver
LTS-1210
LTS-1210C
Steel - Plain
Steel - Cadmium
LTS-1210S Stainless - Plain
LTS-1210SV Stainless - Silver
LTS-1216
LTS-1216C
Steel - Plain
Steel - Cadmium
LTS-1216S Stainless - Plain
LTS-1216SV Stainless - Silver
LTS-1409
LTS-1409C
LTS-1409S
Steel - Plain
Steel - Cadmium
Stainless - Plain
LTS-1409SV Stainless - Silver
LTS-1414
LTS-1414C
Steel- Plain
Steel - Cadmium
LTS-1414S Stainless -Plain
LTS-1414SV Stainless - Silver
LTS-1608
LTS-1608C
LTS-1608S
Steel - Plain
Steel - Cadmium
Stainless - Plain
LTS-1608SV Stainless - Silver
LTS-1612 Steel - Plain
LTS-1612C
LTS-1612S
Steel - Cadmium
Stainless - Plain
LTS-1612SV Stainless - Silver
LTS-1614
LTS-1614C
Steel - Plain
Steel - Cadmium
LTS-1614S Stainless - Plain
LTS-1614SV Stainless - Silver
.562-12 UNC-2B
.562 - 18 UNF-3B
.625-11 UNC-2B
.625 - 18 UNF-3B
.750-10 UNC-2B
.750 - 16 UNF-3B
.875-9 UNC-2B
.875 - 14 UNF-3B
1.000-8 UNC-2B
27,000
30,000
34,000
38,400
50,000
52,300
64,600
71,400
85,000
.877
.877
.940
.940
1.064
1.064
1.252
1.252
1.440
1.000 - 12 UNF-3B 90,500 1.440
1.000 - 14 UNF-3B 92,500 1.440
.865
.865
.928
.928
1.052
1.052
1.239
1.239
1.427
1.427
1.427
.987
.987
1.059
1.059
1.200
1.200
1.414
1.414
1.628
1.628
1.628
.696
.696
.759
.759
.884
.884
1.009
1.009
1.134
1.134
1.134
.385
.385
.410
.410
.505
.505
.570
.570
.635
.635
.635
.865
.865
.928
.928
1.052
1.052
1.239
1.239
1.427
1.427
1.427
5.7
7.15
8.73
8.73
12.38
12.38
19.46
19.46
28.52
28.52
28.52
4

FLEXTOP ® LOCKNUTS
THIN HEIGHT LIGHT HEX
NOMINAL
THREAD
SIZE
LOCKNUT
TECHNOLOGY
PART NO.
MATERIAL
AND
FINISH
THREAD
PROOF
LOAD
LB.
W
WIDTH ACROSS
FLATS
MAX. MIN.
C
WIDTH
H S B
ACROSS THICKNESS HEIGHT OF BEARING
CORNERS MAX.
HEX. MIN DIA. MIN.
REF.
WEIGHT
LB./100
APPROX.
#6
#8
#10
#12
1/4"
5/16"
LTT-420
LTT-420C
LTT-420S
LTT-420SV
LTT-428
LTT-428C
LTT-428S
LTT-428SV
LTT-518
LTT-518C
LTT-518S
LTT-518SV
LTT-524
LTT-524C
LTT-524S
LTT-524SV
LTT-632
LTT-632C
LTT-632S
LTT-632SV
LTT-640
LTT-640C
LTT-640S
LTT-640SV
LTT-832
LTT-832C
LTT-832S
LTT-832SV
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
LTT-836
LTT-836C
LTT-836S
LTT-836SV
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
LTT-1024
LTT-1024C
Steel - Plain
Steel - Cadmium
LTT-1024S Stainless - Plain
LTT-1024SV Stainless - Silver
LTT-1032
LTT-1032C
LTT-1032S
Steel - Plain
Steel - Cadmium
Stainless - Plain
LTT-1032SV Stainless - Silver
LTT-1224
LTT-1224C
LTT-1224S
Steel - Plain
Steel - Cadmium
Stainless - Plain
LTT-1224SV Stainless - Silver
LTT-1228
LTT-1228C
Steel - Plain
Steel - Cadmium
LTT-1228S Stainless - Plain
LTT-1228SV Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
.138 - 32 UNC-3B
.138 - 40 UNF-3B
.164 - 32 UNC-3B
.164 - 36 UNF-3B
.190 - 24 UNC-3B
.190 - 32 UNF-3B
.216 - 24 UNC-3B
.216 - 28 UNF-3B
.250 - 20 UNC-2B
.250 - 28 UNF-3B
.312 - 18 UNC-2B
.312 - 24 UNF-3B
1,270 .313
1,420
1,960
2,060
2,340
2,800
3,380
3,610
4,450
5,090
4,980
5,510
.313
.345
.345
.376
.376
.439
.439
.439
.439
.502
.502
.305
.305
.336
.336
.367
.367
.430
.430
.430
.430
.492
.492
.347
.347
.383
.383
.419
.419
.491
.491
.491
.491
.561
.561
.141
.141
.188
.188
.188
.188
.209
.209
.219
.219
.266
.266
.036
.036
.070
.070
.065
.065
.071
.071
.075
.075
.097
.097
.305
.305
.336
.336
.367
.367
.430
.430
.430
.430
.492
.492
.20
.20
.35
.35
.38
.38
.62
.62
.61
.90
.97
.97
5

FLEXTOP ® LOCKNUTS
THIN HEIGHT LIGHT HEX
NOMINAL
THREAD
SIZE
LOCKNUT
TECHNOLOGY
PART NO.
MATERIAL
AND
FINISH
THREAD
PROOF
LOAD
LB.
W
WIDTH ACROSS
FLATS
MAX. MIN.
C
WIDTH
H S B
ACROSS THICKNESS HEIGHT OF BEARING
CORNERS MAX.
HEX. MIN DIA. MIN.
REF.
WEIGHT
LB./100
APPROX.
3/8"
7/16"
1/2"
9/16"
5/8"
3/4"
LTT-616
LTT-616C
LTT-616S
LTT-616SV
LTT-624
LTT-624C
LTT-624S
LTT-624SV
LTT-714
LTT-714C
LTT-714S
LTT-714SV
LTT-720
LTT-720C
LTT-720S
LTT-720SV
LTT-813
LTT-813C
LTT-813S
LTT-813SV
LTT-820
LTT-820C
LTT- 820S
LTT- 820SV
LTT-912
LTT-912C
LTT-912S
LTT-912SV
LTT-918
LTT-918C
LTT-918S
LTT-918SV
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
LTT-1011
LTT-1011C
Steel - Plain
Steel - Cadmium
LTT-1011S Stainless - Plain
LTT-1011SV Stainless - Silver
LTT-1018
LTT-1018C
Steel - Plain
Steel - Cadmium
LTT-1018S Stainless - Plain
LTT-1018SV Stainless - Silver
LTT-1210
LTT-1210C
Steel - Plain
Steel - Cadmium
LTT-1210S Stainless - Plain
LTT-1210SV Stainless - Silver
LTT-1216
LTT-1216C
LTT-1216S
Steel - Plain
Steel - Cadmium
Stainless - Plain
LTT-1216SV Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
Steel - Plain
Steel - Cadmium
Stainless - Plain
Stainless - Silver
.375 - 16 UNC-2B
.375 - 24 UNF-3B
.437-14 UNC-2B
.437 - 20 UNF-3B
.500-13 UNC-2B
.500 - 20 UNF-3B
.562-12 UNC-2B
.562 - 18 UNF-3B
.625-11 UNC-2B
.625 - 18 UNF-3B
.750-10 UNC-2B
.750 - 16 UNF-3B
7,360
8,340
10,100
11,300
11,400
12,800
14,600
16,200
18,100
20,500
.564
.564
.627
.627
.752
.752
.877
.877
.940
.940
26,800 1.064
29,800 1.064
.553
.553
.616
.616
.741
.741
.865
.865
.928
.928
1.052
1.052
.631
.631
.703
.703
.846
.846
.987
.987
1.059
1.059
1.200
1.200
.282
.282
.328
.328
.328
.328
.368
.368
.399
.399
.415
.415
.108
.108
.138
.138
.121
.121
.135
.135
.147
.147
.155
.155
.553
.553
.616
.616
.741
.741
.865
.865
.928
.928
1.052
1.052
1.69
1.69
1.71
1.71
2.39
2.39
3.66
3.66
4.38
4.38
6.04
6.04
6

FLEXTOP ® LOCKNUTS
THIN HEIGHT LIGHT HEX
NOMINAL
THREAD
SIZE
LOCKNUT
TECHNOLOGY
PART NO.
7/8"
1"
1-1/8"
1-1/4"
1-3/8"
1-1/2"
MATERIAL
AND
FINISH
THREAD
PROOF
LOAD
LB.
W
WIDTH ACROSS
FLATS
MAX. MIN.
C
WIDTH
H S B
ACROSS THICKNESS HEIGHT OF BEARING
CORNERS MAX.
HEX. MIN DIA. MIN.
REF.
WEIGHT
LB./100
APPROX.
LTT-1409
LTT-1409C
Steel - Plain
Steel - Cadmium
LTT-1409S Stainless - Plain
LTT-1409SV Stainless - Silver
LTT-1414
LTT-1414C
Steel - Plain
Steel - Cadmium
LTT-1414S Stainless - Plain
LTT-1414SV Stainless - Silver
LTT-1608
LTT-1608C
Steel - Plain
Steel - Cadmium
LTT-1608S Stainless - Plain
LTT-1608SV Stainless - Silver
LTT-1612
LTT-1612C
Steel - Plain
Steel - Cadmium
LTT-1612S Stainless - Plain
LTT-1612SV Stainless - Silver
LTT-1614
LTT-1614C
Steel - Plain
Steel - Cadmium
LTT-1614S Stainless - Plain
LTT-1614SV Stainless - Silver
LTT-1812
LTT-1812C
Steel - Plain
Steel - Cadmium
LTT-1812S Stainless - Plain
LTT-1812SV Stainless - Silver
LTT-2012
LTT-2012C
Steel - Plain
Steel - Cadmium
LTT-2012S Stainless - Plain
LTT-2012SV Stainless - Silver
LTT-2212
LTT-2212C
Steel - Plain
Steel - Cadmium
LTT-2212S Stainless - Plain
LTT-2212SV Stainless - Silver
LTT-2412
LTT-2412C
Steel - Plain
Steel - Cadmium
LTT-2412S Stainless - Plain
LTT-2412SV Stainless - Silver
.875-9 UNC-2B
.875 - 14 UNF-3B
1.000-8 UNC-2B
36,940
40,800
48,500
1.000 - 12 UNF-3B 53,000 1.440
1.000 - 14 UNS-3B 54,400 1.440
1.125-12 UNF-3B
1.250-12 UNF-3B
1.375-12 UNF-3B
68,500
85,800
90,700
1.252
1.252
1.440
1.627
1.814
2.002
1.500-12 UNF-3B 109,000 2.190
1.239
1.239
1.427
1.427
1.427
1.614
1.801
1.988
2.176
1.414
1.414
1.628
1.628
1.628
1.842
2.056
2.269
2.484
.477
.477
.571
.571
.571
.634
.759
.821
.884
.166
.166
.218
.218
.218
.238
.311
.325
.350
1.239
1.239
1.427
1.427
1.427
1.614
1.801
1.988
2.176
9.44
9.44
15.24
15.24
15.24
19.19
39.14
41.99
57.56
7

UNIFIED THREADS
FLEXTOP ® locknuts are available in both Unified
Coarse and Unified Fine Thread Series. They are made with Class 2B and Class 3B thread fit.
THREAD CLASS
Light Hex
UNC-3B - #2 through #12
UNC-2B - 1/4" through 2"
UNF-3B - #2 through 2"
Typical Tightening Torques for Cadmium Plated
Steel FLEXTOP ® Nuts on Cadmium Plated or
Unplated Bolts size threads per in.
40,000 psi preload* 90,000 psi preload* tightening torque load tightening torque load
(inch-lb.) (in pounds) (inch-lb.) (in pounds)
1/4
5/16
3/8
7/16
1/2
9/16
5/8
3/4
7/8
1
1-1/8
1-1/4
1-3/8
1-1/2
18
10
16
9
14
13
20
12
18
11
20
28
18
24
16
24
14
20
7
12
6
12
6
12
8
12
14
7
12
780
1,100
1,200
1,500
1,600
375
420
510
580
690
28
60
100
110
170
190
260
280
2,000
2,150
2,200
2,500
2,800
3,400
3,700
4,200
4,800
5,600
6,300
5,700
6,400
7,300
8,100
9,000
10,200
13,400
14,900
18,500
20,200
1270
1,450
2,100
2,300
3,100
3,500
4,270
4,760
24,200
26,500
26,700
30,500
34,200
38,800
42,900
46,200
52,500
55,700
63,100
840
940
1,150
1,300
1,550
1,750
2,400
2,650
3,300
3,650
115
130
230
250
385
425
575
630
4,400
4,800
4,850
5,700
6,300
7,600
8,300
9,500
10,800
12,600
14,200
2 860
3,275
4,720
5,200
7,000
7,900
9,600
10,700
12,800
14,400
16,400
18,300
20,300
23,000
30,100
33,600
41,600
45,900
54,500
59,700
60,200
68,700
77,000
87,300
96,600
103,900
118,300
126,500
142,300
REUSABILITY
All FLEXTOP ® locknuts, except those made of stainless steel without silver plating, meet the locking torque requirements of MIL-N-25027.
Tests required by MIL-N-25027 include 15 unseated installation and removal cycles with the bolt fully engaging the locking area on each cycle.
Unplated Stainless Steel
FLEXTOP ® locknuts are coated with a torquetension control fluid (wax-type) to minimize galling. However, they are not recommended for applications requiring reusability.
MATERIAL
Steel
Stainless Steel
FINISHES
FINISH
Plain or Cadmium Plated
Plain or Silver Plated
Nuts with these finishes are listed in this catalog. For special application, a wide variety of other finishes is available, including zinc, phos/oil, and passivation.
FLEXTOP® MAXIMUM TEMPERATURE LIMITS
STEEL
STAINLESS
STEEL
MATERIAL
PLAIN CADMIUM
500ºF
290ºC
800ºF
425ºC
450ºF
235ºC
450ºF
235ºC
FINISH
SILVER ZINC
550ºF
290ºC
800ºF
425ºC
450ºF
235ºC
450ºF
235ºC
WARNING: Every bolted joint is unique and the optimum tightening torque should be determined for each application after careful consideration.
8

FLEXTOP ® Locknuts are produced on modern, precision equipment designed exclusively for this purpose. Locking torques are held to very close limits to permit uniform control of preload in the assembly process.
Unlike some poor quality imports, all of our “locking” is done at our production facility in Illinois, USA. With our precision manufacturing methods you can be assured of uniformly close control of locking torques.

351 S. LOMbArD rOAD • ADDISON, ILLINOIS 60101 • (630) 628-5330 • FAx: (630) 628-5331