Twin Lock Washers®

Twin Lock Washers®

Steel/Stainless

WTL1 — Carbon Steel
WTL2 — 316L Stainless Steel
WTL3 — 254 SMO Stainless Steel

*Sold in pairs*

Twin Lock Washers
Washer Size Screw
Size
d
min.-
max.
D
min.-
max.
Carbon Steel Stainless AISI 316L Stainless 254 SMO Pkg. (Pairs)
h pair
min.-
max.
Order # h pair
min.-
max.
Order # h pair
min.-
max.
Order #
3.4x7.0 M3 #5 3.3-3.5 6.8-7.2 1.55-2.05 WTL1-003-0000 1.75-2.25 WTL2-003-0000 1.75-2.25 WTL3-003-0000 200
3.9x7.6 M3.5 #6 3.8-4.0 7.4-7.8 1.55-2.05 WTL1-3.5-0000 1.75-2.25 WTL2-3.5-0000 1.75-2.25 WTL3-3.5-0000 200
3.9x9.0 3.8-4.0 8.8-9.2 1.55-2.05 WTL1-3.5-0001 1.75-2.25 WTL2-3.5-0001 1.75-2.25 WTL3-3.5-0001 200
4.4x7.6 M4 #8 4.3-4.5 7.4-7.8 1.55-2.05 WTL1-004-0000 1.75-2.25 WTL2-004-0000 1.75-2.25 WTL3-004-0000 200
4.4x9.0 4.3-4.5 8.8-9.2 1.55-2.05 WTL1-004-0001 1.75-2.25 WTL2-004-0001 1.75-2.25 WTL3-004-0001 200
5.4x9.0 M5 #10 5.3-5.5 8.8-9.2 1.55-2.05 WTL1-005-0000 1.75-2.25 WTL2-005-0000 1.75-2.25 WTL3-005-0000 200
5.4x10.8 5.3-5.5 10.6-11.0 1.55-2.05 WTL1-005-0001 1.75-2.25 WTL2-005-0001 1.75-2.25 WTL3-005-0001 200
6.5x10.8 M6 6.4-6.6 10.6-11.0 1.55-2.05 WTL1-006-0000 1.75-2.25 WTL2-006-0000 1.75-2.25 WTL3-006-0000 200
6.5x13.5 6.4-6.6 13.3-13.7 2.25-2.75 WTL1-006-0001 1.75-2.25 WTL2-006-0001 1.75-2.25 WTL3-006-0001 200
7.2x11.5 1/4" 7.1-7.3 11.3-11.7 1.55-2.05 WTL1-007-0000 1.75-2.25 WTL2-007-0000 1.75-2.25 WTL3-007-0000 200
7.2x13.5 7.1-7.3 13.3-13.7 2.25-2.75 WTL1-007-0001 1.75-2.25 WTL2-007-0001 1.75-2.25 WTL3-007-0001 200
8.7x13.5 M8 5/16" 8.6-8.8 13.3-13.7 2.25-2.75 WTL1-008-0000 1.75-2.25 WTL2-008-0000 1.75-2.25 WTL3-008-0000 200
8.7x16.6 8.6-8.8 16.4-16.8 2.25-2.75 WTL1-008-0001 1.75-2.25 WTL2-008-0001 1.75-2.25 WTL3-008-0001 200
10.3x16.6 3/8" 10.2-10.4 16.4-16.8 2.25-2.75 WTL1-009-0000 1.75-2.25 WTL2-009-0000 1.75-2.25 WTL3-009-0000 200
10.3x21.0 10.2-10.4 20.8-21.2 2.25-2.75 WTL1-009-0001 1.75-2.25 WTL2-009-0001 1.75-2.25 WTL3-009-0001 200
10.7x16.6 M10 10.5-10.9 16.4-16.8 2.25-2.75 WTL1-010-0000 1.75-2.25 WTL2-010-0000 1.75-2.25 WTL3-010-0000 200
10.7x21.0 10.5-10.9 20.8-21.2 2.25-2.75 WTL1-010-0001 1.75-2.25 WTL2-010-0001 1.75-2.25 WTL3-010-0001 200
11.4x18.5 M11 7/16" 11.2-11.6 18.3-18.7 2.25-2.75 WTL1-011-0000 1.75-2.25 WTL2-011-0000 1.75-2.25 WTL3-011-0000 200
13.0x19.5 M12 12.8-13.2 19.3-19.7 2.25-2.75 WTL1-012-0000 1.75-2.25 WTL2-012-0000 1.75-2.25 WTL3-012-0000 200
13.0x25.4 12.8-13.2 25.2-25.6 3.15-3.65 WTL1-012-0001 2.75-3.25 WTL2-012-0001 2.75-3.25 WTL3-012-0001 100
13.5x19.5 1/2" 13.3-13.7 19.3-19.7 2.25-2.75 WTL1-013-0000 1.75-2.25 WTL2-013-0000 1.75-2.25 WTL3-013-0000 200
13.5x25.4 13.3-13.7 25.2-25.6 3.15-3.65 WTL1-013-0001 2.75-3.25 WTL2-013-0001 2.75-3.25 WTL3-013-0001 100
15.2x23.0 M14 9/16" 15.0-15.4 22.8-23.2 3.15-3.65 WTL1-014-0000 2.75-3.25 WTL2-014-0000 2.75-3.25 WTL3-014-0000 100
15.2x30.7 15.0-15.4 30.5-30.9 3.15-3.65 WTL1-014-0001 2.75-3.25 WTL2-014-0001 2.75-3.25 WTL3-014-0001 100
17.0x25.4 M16 5/8" 16.8-17.2 25.2-25.6 3.15-3.65 WTL1-016-0000 2.75-3.25 WTL2-016-0000 2.75-3.25 WTL3-016-0000 100
17.0x30.7 16.8-17.2 30.5-30.9 3.15-3.65 WTL1-016-0001 2.75-3.25 WTL2-016-0001 2.75-3.25 WTL3-016-0001 100
19.5x29.0 M18 19.3-19.7 28.8-29.2 3.15-3.65 WTL1-018-0000 2.75-3.25 WTL2-018-0000 2.75-3.25 WTL3-018-0000 100
19.5x34.5 19.3-19.7 34.3-34.7 3.15-3.65 WTL1-018-0001 2.75-3.25 WTL2-018-0001 2.75-3.25 WTL3-018-0001 100
20.0x30.7 3/4" 19.8-20.2 30.5-30.9 3.15-3.65 WTL1-019-0000 2.75-3.25 WTL2-019-0000 2.75-3.25 WTL3-019-0000 100
20.0x39.0 19.8-20.2 38.8-39.2 3.15-3.65 WTL1-019-0001 2.75-3.25 WTL2-019-0001 2.75-3.25 WTL3-019-0001 100
21.4x30.7 M20 21.2-21.6 30.5-30.9 3.15-3.65 WTL1-020-0000 2.75-3.25 WTL2-020-0000 2.75-3.25 WTL3-020-0000 100
21.4x39.0 21.2-21.6 38.8-39.2 3.15-3.65 WTL1-020-0001 2.75-3.25 WTL2-020-0001 2.75-3.25 WTL3-020-0001 100
23.4x34.5 M22 7/8" 23.2-23.6 34.3-34.7 3.15-3.65 WTL1-022-0000 2.75-3.25 WTL2-022-0000 2.75-3.25 WTL3-022-0000 100
23.4x42.0 23.2-23.6 41.8-42.2 4.35-4.85 WTL1-022-0001 2.75-3.25 WTL2-022-0001 2.75-3.25 WTL3-022-0001 50
25.3x39.0 M24 25.1-25.5 38.8-39.2 3.15-3.65 WTL1-024-0000 2.75-3.25 WTL2-024-0000 2.75-3.25 WTL3-024-0000 100
25.3x48.5 25.1-25.5 48.3-48.7 4.35-4.85 WTL1-024-0001 2.75-3.25 WTL2-024-0001 2.75-3.25 WTL3-024-0001 50
27.9x39.0 1" 27.7-28.1 38.8-39.2 3.15-3.65 WTL1-025-0000 2.75-3.25 WTL2-025-0000 2.75-3.25 WTL3-025-0000 100
27.9x48.5 27.7-28.1 48.3-48.7 4.35-4.85 WTL1-025-0001 2.75-3.25 WTL2-025-0001 2.75-3.25 WTL3-025-0001 50
28.4x42.0 M27 28.2-28.6 41.7-42.3 5.55-6.05 WTL1-027-0000 6.30-6.80 WTL2-027-0000 5.55-6.05 WTL3-027-0000 50
28.4x48.5 28.2-28.6 48.2-48.8 5.55-6.05 WTL1-027-0001 6.30-6.80 WTL2-027-0001 5.55-6.05 WTL3-027-0001 25
31.4x47.0 M30 1 1/8" 31.2-31.6 46.7-47.3 5.55-6.05 WTL1-030-0000 6.30-6.80 WTL2-030-0000 5.55-6.05 WTL3-030-0000 50
31.4x58.5 31.2-31.6 58.2-58.8 6.35-6.85 WTL1-030-0001 6.30-6.80 WTL2-030-0001     25
34.4x48.5 M33 1 1/4" 34.2-34.6 48.2-48.8 5.55-6.05 WTL1-033-0000 6.30-6.80 WTL2-033-0000 5.55-6.05 WTL3-033-0000 25
34.4x58.5 34.2-34.6 58.2-58.8 6.35-6.85 WTL1-033-0001         25
37.4x55.0 M36 1 3/8" 37.2-37.6 54.7-55.3 6.35-6.85 WTL1-036-0000 6.30-6.80 WTL2-036-0000 5.55-6.05 WTL3-036-0000 25
37.4x63.0 37.2-37.6 62.7-63.3 6.35-6.85 WTL1-036-0001         25
40.4x58.5 M39 1 1/2" 40.2-40.6 58.2-58.8 6.35-6.85 WTL1-039-0000 6.30-6.80 WTL2-039-0000 5.55-6.05 WTL3-039-0000 25
43.2x63.0 M42 43.0-43.4 62.7-63.3 6.35-6.85 WTL1-042-0000 6.30-6.80 WTL2-042-0000     25

Materials

  • Carbon steel, hardness 465-550 HV 10 after hardening and tempering
  • Stainless Steel AISI 316L EN 10088-2 1.4404, surface hardness ≥ 550 HV 0.05 after surface hardening (Kolsterising®)
  • Stainless Steel 254 SMO EN 10088 1.4547, surface hardness ≥ 600 HV 0.05 after surface hardening (Kolsterising®)
  • Inconel® 718 DIN 17444 2.4668, surface hardness ≥ 620 HV 0.05 after surface hardening (Kolsterising®)
  • Other materials are available upon request (Hastelloy® C-276, etc…)

Surface Treatments

  • Delta Protekt® KL100 + VH301 Cr6 free, red corrosion resistance min. 600 hours (salt spray corrosion test according to ISO 9227)
  • Mechanical Zinc-plating + sealing Cr6 free, red corrosion resistance min. 600 hours (salt spray corrosion test according to ISO 9227)
  • Other surface treatments may be available according to minimum amount orders

Advantages of Twin Lock® washers

  • The fastening solution ensures the best locking performance in the presence of vibration and dynamic loads
  • The system works independently from the type of lubrication used. The system guarantees a secure locking in dry as well as in lubricated conditions. However, high quality lubricant is recommended in order to maximize the performance of this fastening system
  • The locking system is reusable without loss of performance. In case of reuse, the correct positioning of the washers - cams face against cams face - has to be checked
  • The system locks the fixing elements with high as well as low pre-load
  • The system is reusable with any kind of bolt/nut of any class of resistance (up to 12.9)
  • The system does not require retightening
  • The surface treatments are Cr6 free and do not present any risk of hydrogen embrittlement
  • The pieces are glued together cams face against cams face, in order to deliver an assembly-friendly system

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Torque Guidelines of Grower Twin-Lock® Standard Series Delta Protekt® KL100+VH301GZ

Washer dimensions dxD [mm]  Screw size Bolt 8.8a Oiled Bolt 8.8a Dry Bolt 10.9b Oiled Bolt 10.9b Dry Bolt 12.9c Oiled Bolt 12.9c Dry
Torque [Nm] Loadd [kN] Torque [Nm] Loadd [kN] Torque [Nm] Loadd [kN] Torque [Nm] Loadd [kN] Torque [Nm] Loadd [kN] Torque [Nm] Loadd [kN]
3.4x7.0 M3 #5 1.7 2.4 1.9 2.4 2.5 3.4 2.6 3.4 3 4.1 3 4.1
4.4x7.6 M4 #8 4.1 4.2 4.5 4.2 5 5.9 5.2 5.9 5.8 7.1 6.1 7.1
5.4x9.0 M5 #10 8.5 6.8 8.5 6.8 8.9 9.6 9.5 9.6 10.2 11.5 10.8 11.5
6.5x10.8 M6 12.2 9.7 12.5 9.7 17.2 13.6 19 13.6 18 16.3 19.5 16.3
8.7x13.5 M8 5/16" 30 18 31 18 36 25 38 25 45 30 48 30
10.7x16.6 M10 62 28 65 28 77 39 82 39 86 47 88 47
13.0x19.5 M12 100 40 103 40 120 57 125 57 133 68 139 68
15.2x23.0 M14 9/16" 146 55 150 55 198 78 210 78 217 94 221 94
17.0x25.4 M16 5/8" 260 75 267 75 322 106 330 106 339 127 347 127
19.5x29.0 M18 310 92 336 92 430 130 438 130 445 156 452 156
21.4x30.7 M20 486 118 499 118 540 165 552 165 593 198 604 198
23.4x34.5 M22 7/8" 583 146 592 146 691 205 701 205 817 246 839 246
25.3x39.0 M24 760 169 778 169 950 238 964 238 1070 286 1125 286
28.4x42.0 M27 1050 221 1070 221 1440 310 1475 310 1605 372 1680 372
31.4x47.0 M30 1 1/8" 1470 269 1510 269 1935 378 1980 378 2140 454 2180 454

Remarks:
Test conditions according to ISO 16047, bearing surface hardness 200-250 Hv, roughness Ra 0.6 uncoated and degreased
a Screw class 8.8 DIN 931 / DIN 933 uncoated + Nut DIN 934 uncoated, coarse pitch thread
b Screw class 10.9 DIN 931 / DIN 933 uncoated + Nut DIN 934 uncoated, coarse pitch thread
c Screw class 12.9 DIN 912 uncoated + Nut DIN 934 uncoated, coarse pitch thread
d 75% of nominal yield point (stress at 0.2% non-proportional elongation Rp0.2) according to ISO 898-1

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Torque Guidelines of Grower Twin-Lock® Standard Series in Stainless Steel

Washer dimensions dxD [mm] Screw size AISI 316L
Bolt A4-70a Lubricatedd Bolt A4-80b Lubricatedd
Torque [Nm] Loadc [kN] Torque [Nm] Loadc [kN]
3.4x7.0 M3 #5 0.8 1.5 1.2 2
4.4x7.6 M4 #8 2 2.6 2.5 3.4
5.4x9.0 M5 #10 3.7 4.1 5 5.5
6.5x10.8 M6 6.5 5.9 7.5 7.8
8.7x13.5 M8 5/16" 17 11 20 14
10.7x16.6 M10 32 17 40 23
13.0x19.5 M12 48 25 65 33
15.2x23.0 M14 9/16" 92 34 120 45
17.0x25.4 M16 5/8" 130 46 190 61
19.5x29.0 M18 179 56 248 75
21.4x30.7 M20 260 72 340 95
23.4x34.5 M22 7/8" 355 89 475 118
25.3x39.0 M24 465 103 610 137
28.4x42.0 M27 665 134 890 179
31.4x47.0 M30 1 1/8" 900 164 1150 219

Remarks:
Test conditions according to ISO 16047, bearing surface hardness 200-250 Hv, roughness Ra 0.6 uncoated and degreased
a Screw class A4-70 DIN 931 / DIN 933 + Nut DIN 934 coarse pitch thread
b Screw class A4-80 DIN 931 / DIN 933 + Nut DIN 934 coarse pitch thread
c 65% of nominal yield point (stress at 0.2% non-proportional elongation Rp0.2) according to ISO 898-1
d Lubricated with molybdenum disulfide paste

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