NSK-MStrength classes up to 8.8
Areas of application
- Highly stressed and high-strength bolted connections in accordance with VDI 2230-1
- Force-fit, static and dynamic transmission of the operating load via the braced components
- Strength classes up to and including 8.8
- Circular hole connections
Special features
- Suitable for high preload forces
- Defined, constant coefficient of friction
- Increases the flexibility of the screw connection
- Special spring characteristics / optimum residual spring behaviour for strength classes up to and including 8.8 (Characteristic spring curves shown in M-Design)
- Locking element to prevent loosening & automatic unscrewing
- Complies with standards DIN 267-26, DIN 25201-4, DIN EN 17976
Comparison of possible solutions for highly stressed screw connections Strength class 8.8
| Spring/profile Locking edge ring1 Spring washer2 with washer |
Wedge disc pairs (flat design) |
Wedge disc pairs (conical design) |
Clamping disc (DIN6796) |
Lock washer SK-M | NSK-M | |
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| Damage to the counterclaims |
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| Defined / reproducible contact pressure (coefficient of friction) |
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| Improved compliance with short clamping lengths |
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| Compensation for slackening effects3 |
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| Compensation of loosening effects4 |
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| Acquisition costs compared to washer DIN 1255 |
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1
DIN 127, 128, 6905, 7980 etc.
2
DIN 137, 6904
3
according to VDI 2230, DIN 267-26
4
in accordance with DIN 65151 / DIN 25201 - 4
5
same / higher / high
Executions
| Spring steel C60 EN 1.1211 |
Stainless steel A41 EN 1.4401 |
Other materials EN 1.4547, EN 2.4819, EN 2.4668 on request |
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|---|---|---|---|
| Hardness / Strength | ≥ 430 HV10 | ≥ 595 N/mm2 | depending on material |
| Coating | Zinc flake coating | - | - |
| Corrosion protection | > 720h in the salt spray test (according to ISO 9227) | PREN 27 (related to base material) | depending on material |
| Temperature range | -40°C to 150°C | -40°C to 150°C | depending on material |
| Screw quality | 5.6 / 8.8 / 10.9 / 12.9 | up to and including A4-70 |
depending on material |
| Dimension range | M3-M30 | M4 - M24 | as required |
1
can also be used for stainless steel A2 screws, e.g. EN 1.4301 or EN 1.4310
Applications
Why do screw connections come loose?
How does an NSK-M work?
Force-locking effect with curved geometry matched to the preload force depending on the strength class
- Increases the flexibility of a bolted joint
- Prevents slackening effects and supports the locking effect against selfacting loosening
Form locking effect due to the interlocking under the screw head or on the nut
- Supports the locking effect against selfacting loosening
How are NSK-M tested?
Minimum residual spring force test according to DIN 267-26
Force measurement, if the screw connection is relieved by 20μm (Technical specifications for conical spring steel washers for bolted joints)
Spring characteristic curve, matched to:
- Strength class 10.9 and 12.9 (steel)
- A80 for stainless steel 1.4401
Vibration test according to DIN 65151 & DIN 25201-4 Annex B.
- Application-orientated testing on circular-holes and slotted holes
- Internal testing equipment are verified by external institutes.
Spring steel with zinc flake
| NSK-M | Article No. | DI | DA | S | H | Weight/1.000 St. | Pcs. per unit | 3D Download | Request |
|---|---|---|---|---|---|---|---|---|---|
| NSK-M4 | 070010 | Ø 4.10+0.48 | Ø 10.20-0.40 | 1.00±0.04 | 1.45±0.20 | 0,53 kg | 1.000 | Download | Add to request list |
| NSK-M5 | 070020 | Ø 5.10+0.48 | Ø 12.20-0.40 | 1.20±0.04 | 1.75±0.20 | 0,90 kg | 1.000 | Download | Add to request list |
| NSK-M6 | 070030 | Ø 6.10+0.48 | Ø 14.20-0.43 | 1.40±0.04 | 2.15±0.20 | 1,40 kg | 1.000 | Download | Add to request list |
| NSK-M8 | 070040 | Ø 8.20+0.58 | Ø 18.20-0.52 | 1.40±0.04 | 2.70±0.25 | 2,30 kg | 1.000 | Download | Add to request list |
| NSK-M10 | 070050 | Ø 10.20+0.58 | Ø 22.25-0.52 | 1.60±0.05 | 3.10±0.25 | 3,90 kg | 500 | Download | Add to request list |
| NSK-M12 | 070060 | Ø 12.40+0.58 | Ø 27.25-0.52 | 1.80±0.05 | 3.65±0.25 | 6,50 kg | 500 | Download | Add to request list |
| NSK-M14 | 070070 | Ø 14.40+0.58 | Ø 30.25-0.62 | 2.40±0.06 | 3.90±0.25 | 10,50 kg | 500 | Download | Add to request list |
| NSK-M16 | 070080 | Ø 16.40+0.58 | Ø 32.50-0.62 | 2.50±0.06 | 4.60±0.30 | 12,00 kg | 250 | Download | Add to request list |
| NSK-M18 | 070090 | Ø 18.50+0.75 | Ø 35.00-0.62 | 3.00±0.07 | 4.80±0.30 | 16,30 kg | 250 | Download | Add to request list |
| NSK-M20 | 070100 | Ø 21.00+0.75 | Ø 40.00-0.62 | 3.00±0,07 | 5.00±0.30 | 22,00 kg | 100 | Download | Add to request list |
| NSK-M22 | 070110 | Ø 23.00+0.75 | Ø 45.00-0.62 | 3.50±0.07 | 5.60±0.40 | 33,00 kg | 100 | Download | Add to request list |
| NSK-M24 | 070120 | Ø 25.00+0.75 | Ø 50.00-0.62 | 3.50±0.07 | 5.80±0.40 | 41,00 kg | 100 | Download | Add to request list |
Stainless steel A4 / 1.4401
| NSK-M | Article No. | DI | DA | S | H | Weight/1.000 St. | Pcs. per unit | 3D Download | Request |
|---|---|---|---|---|---|---|---|---|---|
| NSK-M4 | 076010 | Ø 4.10+0.48 | Ø 10.20-0.40 | 1.00±0.04 | 1.45±0.20 | 0,53 kg | 1.000 | Download | Add to request list |
| NSK-M5 | 076020 | Ø 5.10+0.48 | Ø 12.20-0.40 | 1.20±0.04 | 1.75±0.20 | 0,90 kg | 1.000 | Download | Add to request list |
| NSK-M6 | 076030 | Ø 6.10+0.48 | Ø 14.20-0.43 | 1.40±0.04 | 2.15±0.20 | 1,40 kg | 1000 | Download | Add to request list |
| NSK-M8 | 076040 | Ø 8.20+0.58 | Ø 18.20-0.52 | 1.40±0.04 | 2.70±0.25 | 2,30 kg | 1000 | Download | Add to request list |
| NSK-M10 | 076050 | Ø 10.20+0.58 | Ø 22.25-0.52 | 1.60±0.05 | 3.10±0.25 | 3,90 kg | 500 | Download | Add to request list |
| NSK-M12 | 076060 | Ø 12.40+0.58 | Ø 27.25-0.52 | 1.80±0.05 | 3.65±0.25 | 6,50 kg | 500 | Download | Add to request list |
| NSK-M14 | 076070 | Ø 14.40+0.58 | Ø 30.25-0.62 | 2.40±0.06 | 3.90±0.25 | 10,50 kg | 500 | Download | Add to request list |
| NSK-M16 | 076080 | Ø 16.40+0.58 | Ø 32.50-0.62 | 2.50±0.06 | 4.60±0.30 | 12,00 kg | 250 | Download | Add to request list |
| NSK-M20 | 076100 | Ø 21.00+0.75 | Ø 40.00-0.62 | 3.00±0,07 | 5.00±0.30 | 22,00 kg | 100 | Download | Add to request list |
| NSK-M24 | 076120 | Ø 25.00+0.75 | Ø 50.00-0.62 | 3.50±0.07 | 5.80±0.40 | 41,00 kg | 100 | Download | Add to request list |
Technical changes reserved
What is the difference between SK and NSK washers?
| Lock washer (SK Washer) |
New lock washer (NSK washer) |
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|---|---|---|
| State of development |
1990
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2007 cont.
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| Form |
Linear cross- section
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Angled or curved cross-section with bead
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| Compensation of loosening effects1 |
mainly given
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I.O.
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| Compensation of loosening effects2 |
not given (standard from 2005)
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I.O.
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| Fulfilment of the teckentrup product characteristics |
Manufacturer-dependent and to be verified in individual cases
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I.O.
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| Costs |
Identical NSK
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Identical SK
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1
according to DIN 65151 and, if applicable, DIN 25201 - 4 2021-11, depending on design with adapted parameters depending on strength class etc.
2
based on VDI 2230, DIN 267-26 2005-12
The SK washers are produced by different manufacturers worldwide and may have different functional properties with the same external appearance.
SK washer
NSK washer
SK-M (medium) for strength classes ≤ 8.8
Spring steel with zinc flake
| SK-M | Article No. | DI | DA | S | H | Weight/1.000 St. | Pcs. per unit | Request |
|---|---|---|---|---|---|---|---|---|
| SK-M4 | 090310 | Ø 4.10+0.48 | Ø 10.20-0.40 | 1.00±0.04 | 1.30+0.20 | 0,53 kg | 1.000 | Add to request list |
| SK-M5 | 090320 | Ø 5.10+0.48 | Ø 12.20-0.40 | 1.20±0.04 | 1.65+0.20 | 0,90 kg | 1.000 | Add to request list |
| SK-M6 | 090330 | Ø 6.10+0.48 | Ø 14.20-0.43 | 1.40±0.04 | 2.00+0.20 | 1,40 kg | 1.000 | Add to request list |
| SK-M8 | 090340 | Ø 8.20+0.58 | Ø 18.20-0.52 | 1.40±0.04 | 2.20+0.20 | 2,30 kg | 1.000 | Add to request list |
| SK-M10 | 090350 | Ø 10.20+0.58 | Ø 22.25-0.52 | 1.60±0.05 | 2.55+0.20 | 3,90 kg | 500 | Add to request list |
| SK-M12 | 090360 | Ø 12.40+0.58 | Ø 27.25-0.52 | 1.80±0.05 | 2.85+0.20 | 6,50 kg | 500 | Add to request list |
| SK-M14 | 090370 | Ø 14.40+0.58 | Ø 30.25-0.62 | 2.40±0.06 | 3.30+0.20 | 10,50 kg | 500 | Add to request list |
| SK-M16 | 090380 | Ø 16.40+0.58 | Ø 32.50-0.62 | 2.50±0.06 | 3.75+0.20 | 12,00 kg | 250 | Add to request list |
| SK-M18 | 090390 | Ø 18.50+0.75 | Ø 35.00-0.62 | 3.00±0.07 | 4.20+0.30 | 16,30 kg | 250 | Add to request list |
| SK-M20 | 090400 | Ø 21.00+0.75 | Ø 40.00-0.62 | 3.00±0,07 | 4.30+0.40 | 22,00 kg | 100 | Add to request list |
| SK-M22 | 090410 | Ø 23.00+0.75 | Ø 45.00-0.62 | 3.50±0.07 | 5.10+0.50 | 33,00 kg | 100 | Add to request list |
| SK-M24 | 090420 | Ø 25.00+0.75 | Ø 50.00-0.62 | 3.50±0.07 | 5.15+0.50 | 41,00 kg | 100 | Add to request list |
Stainless steel A4 / 1.4401
| SK-M | Article No. | DI | DA | S | H | Weight/1.000 St. | Pcs. per unit | Request |
|---|---|---|---|---|---|---|---|---|
| SK-M4 | 096310 | Ø 4.10+0.48 | Ø 10.20-0.40 | 1.00±0.04 | 1.30+0.20 | 0,53 kg | 1.000 | Add to request list |
| SK-M5 | 096320 | Ø 5.10+0.48 | Ø 12.20-0.40 | 1.20±0.04 | 1.65+0.20 | 0,90 kg | 1.000 | Add to request list |
| SK-M6 | 096330 | Ø 6.10+0.48 | Ø 14.20-0.43 | 1.40±0.04 | 2.00+0.20 | 1,40 kg | 1.000 | Add to request list |
| SK-M8 | 096340 | Ø 8.20+0.58 | Ø 18.20-0.52 | 1.40±0.04 | 2.20+0.20 | 2,30 kg | 1.000 | Add to request list |
| SK-M10 | 096350 | Ø 10.20+0.58 | Ø 22.25-0.52 | 1.60±0.05 | 2.55+0.20 | 3,90 kg | 500 | Add to request list |
| SK-M12 | 096360 | Ø 12.40+0.58 | Ø 27.25-0.52 | 1.80±0.05 | 2.85+0.20 | 6,50 kg | 500 | Add to request list |
| SK-M14 | 096370 | Ø 14.40+0.58 | Ø 30.25-0.62 | 2.40±0.06 | 3.30+0.20 | 10,50 kg | 500 | Add to request list |
| SK-M16 | 096380 | Ø 16.40+0.58 | Ø 32.50-0.62 | 2.50±0.06 | 3.75+0.20 | 12,00 kg | 250 | Add to request list |
Technical changes reserved