Nord-Lock · Stops bolts loosening under vibration
Nord-Lock Original Washers
Nord-Lock Original washers from R Square Technologies, an authorised Nord-Lock distributor in Chennai, supplied across India.
The classic Nord-Lock washer. A pair of washers that locks any bolt facing vibration or dynamic load.
How it works
How original washers work
This animation shows an Original washer pair fitted under a bolt head. The teeth bite into the bolt head and the surface, so the two washers can only move against each other on the cams. When vibration tries to turn the bolt loose, the cams lift and raise the bolt tension, and the turning stops.
Official Nord-Lock Group video, played from YouTube.Product selection
Types and sizes
Nord-Lock offers products in a wide range of sizes, shapes and materials. They are developed to suit even the toughest environments.
| Material | Steel EN1.7182 | Stainless Steel EN1.4404 | Stainless Steel EN1.4547 | Hastelloy 276 | Inconel 718 |
|---|---|---|---|---|---|
| Applications | General steel application | General stainless steel applications Non chlorine / acid environments | General salt water applications, pumps, chloride applications, heat exchangers, nuclear, desalination, food processing & medical equipment | General acidic environments, process and chemical industry, evaporators, offshore downhole tooling | High temperatures – gas turbines, turbo charges, incinerators |
| Material standard | EN 1.7182 | EN 1.4404 | EN 1.4547 | EN 2.4819 or equivalent | EN 2.4668 or equivalent |
| Size range | M3–M130 / #5 to 5" | M3–M80 / #5 to 3 1/8" | M3–M39 / #5 to 1 1/2" | M4–M20 / #8 to 1 1/2" | M4–M20 / #8 to 1 1/2" |
| Corrosion resistance | Minimum 1,000 hours in salt spray test according to ISO 9227 | PREN 27 | PREN 45 | PREN 68 | PREN 29 |
| Hardening | Through hardened | Surface hardened | Surfacehardened | Surface hardened | Surface hardened |
| Washer hardness | ≥ 465HV1 | ≥ 520HV0.05 | ≥ 600HV0.05 | ≥ 520HV0.05 | ≥ 620HV0.05 |
| Coating | Base coat: Delta Protekt® KL100 zinc flake coating. Top coat: VH 302 GZ. Standard products in range M6–M24 are available with Delta Seal GZ Black top coat (SP items not included) | — | — | — | — |
| Bolt grades | Up to 12.9 | Up to A4-80 | — | — | — |
| Temperature range | -50°C to 200°C | -160°C to 500°C | -160°C to 500°C | -160°C to 500°C | -160°C to 700°C |
| Product designation (standard) | NL | NLss | NLss-254 | NLss-276 | NLss-718 |
| Product designation (enlarged, sp) | NLsp | NLspss | NLspss-254 | NLspss-276 | NLspss-718 |
| Laser marking | Batch number and type code | SS | 254 | 276 | 718 |
- How to pick: steel bolt, steel washer. Stainless bolt, stainless washer. Big or slotted hole, pick the enlarged (sp) type.
- How to read the code: NL6spss means Nord-Lock, fits M6, enlarged, stainless.
Applications
Where it is used
- Machines, conveyors and vibrating screens
- Pumps, compressors, gearboxes and motors
- Rolling stock, vehicles and mobile equipment
- Any bolted joint under dynamic load
Key facts
- Locks with bolt tension, not friction
- Works on lubricated bolts
- For bolts up to property class 12.9 (steel) and A4-80 (stainless)
- Reusable in most cases, depending on operating conditions
Dimensions guide
Dimensions and guide
Nord-Lock Original Steel Washers. Delta Protekt® Zinc Flake Coating. Through hardened EN 1.7182.
| Bolt size (metric) | Bolt size (UNC) | Product designation | Øi (mm) | Øo (mm) | Thickness T (mm) | Approx. weight kg/100 pairs | Min. package (pairs) |
|---|---|---|---|---|---|---|---|
| M3 | #5 | NL3 | 3.4 | 7 | 1.8 | 0.03 | 200 |
| M3.5 | #6 | NL3.5 | 3.9 | 7.6 | 1.8 | 0.04 | 200 |
| M3.5 | #6 | NL3.5sp | 3.9 | 9 | 1.8 | 0.06 | 200 |
| M4 | #8 | NL4 | 4.4 | 7.6 | 1.8 | 0.04 | 200 |
| M4 | #8 | NL4sp | 4.4 | 9 | 1.8 | 0.06 | 200 |
| M5 | #10 | NL5 | 5.4 | 9 | 1.8 | 0.05 | 200 |
| M5 | #10 | NL5sp | 5.4 | 10.8 | 1.8 | 0.11 | 200 |
| M6 | — | NL6 | 6.5 | 10.8 | 1.8 | 0.07 | 200 |
| M6 | — | NL6sp | 6.5 | 13.5 | 2.5 | 0.2 | 200 |
| 1/4” | — | NL1/4” | 7.2 | 11.5 | 2.5 | 0.08 | 200 |
| 1/4” | — | NL1/4”sp | 7.2 | 13.5 | 2.5 | 0.18 | 200 |
| M8 | 5/16” | NL8 | 8.7 | 13.5 | 2.5 | 0.15 | 200 |
| M8 | 5/16” | NL8sp | 8.7 | 16.6 | 2.5 | 0.28 | 200 |
| 3/8” | — | NL3/8” | 10.3 | 16.6 | 2.5 | 0.23 | 200 |
| 3/8” | — | NL3/8”sp | 10.3 | 21 | 2.5 | 0.48 | 200 |
| M10 | — | NL10 | 10.7 | 16.6 | 2.5 | 0.22 | 200 |
| M10 | — | NL10sp | 10.7 | 21 | 2.5 | 0.47 | 200 |
| M11 | 7/16” | NL11 | 11.4 | 18.5 | 2.5 | 0.29 | 200 |
| M12 | — | NL12 | 13 | 19.5 | 2.5 | 0.29 | 200 |
| M12 | — | NL12sp | 13 | 25.4 | 3.4 | 0.93 | 100 |
| 1/2” | — | NL1/2” | 13.5 | 19.5 | 2.5 | 0.27 | 200 |
| 1/2” | — | NL1/2”sp | 13.5 | 25.4 | 3.4 | 0.9 | 100 |
| M14 | 9/16” | NL14 | 15.2 | 23 | 3.4 | 0.56 | 100 |
| M14 | 9/16” | NL14sp | 15.2 | 30.7 | 3.4 | 1.41 | 100 |
| M16 | 5/8” | NL16 | 17 | 25.4 | 3.4 | 0.67 | 100 |
| M16 | 5/8” | NL16sp | 17 | 30.7 | 3.4 | 1.28 | 100 |
| M18 | — | NL18 | 19.5 | 29 | 3.4 | 0.89 | 100 |
| M18 | — | NL18sp | 19.5 | 34.5 | 3.4 | 1.58 | 100 |
| 3/4” | — | NL3/4” | 20 | 30.7 | 3.4 | 1.05 | 100 |
| 3/4” | — | NL3/4”sp | 20 | 39 | 3.4 | 2.21 | 100 |
| M20 | — | NL20 | 21.4 | 30.7 | 3.4 | 0.93 | 100 |
| M20 | — | NL20sp | 21.4 | 39 | 3.4 | 2.09 | 100 |
| M22 | 7/8” | NL22 | 23.4 | 34.5 | 3.4 | 1.25 | 100 |
| M22 | 7/8” | NL22sp | 23.4 | 42 | 4.6 | 3.19 | 50 |
| M24 | — | NL24 | 25.3 | 39 | 3.4 | 1.74 | 100 |
| M24 | — | NL24sp | 25.3 | 48.5 | 4.6 | 4.51 | 50 |
| 1” | — | NL1” | 27.9 | 39 | 3.4 | 1.53 | 100 |
| 1” | — | NL1”sp | 27.9 | 48.5 | 4.6 | 4.2 | 50 |
| M27 | — | NL27 | 28.4 | 42 | 5.8 | 3.14 | 50 |
| M27 | — | NL27sp | 28.4 | 48.5 | 5.8 | 5.27 | 25 |
| M30 | 1 1/8” | NL30 | 31.4 | 47 | 5.8 | 4.1 | 50 |
| M30 | 1 1/8” | NL30sp | 31.4 | 55 | 5.8 | 7 | 25 |
| M33 | 1 1/4” | NL33 | 34.4 | 48.5 | 5.8 | 3.89 | 25 |
| M33 | 1 1/4” | NL33sp | 34.4 | 58.5 | 5.8 | 8 | 25 |
| M36 | 1 3/8” | NL36 | 37.4 | 55 | 5.8 | 5.49 | 25 |
| M36 | 1 3/8” | NL36sp | 37.4 | 63 | 5.8 | 8.58 | 25 |
| M39 | 1 1/2” | NL39 | 40.4 | 58.5 | 5.8 | 5.89 | 25 |
| M42 | — | NL42 | 43.2 | 63 | 5.8 | 7.97 | 25 |
| M45 | 1 3/4” | NL45 | 46.2 | 70 | 7 | 10.2 | 25 |
| M48 | — | NL48 | 49.6 | 75 | 7 | 12 | 25 |
| M52 | 2” | NL52 | 53.6 | 80 | 7 | 13 | 25 |
| M56 | 2 1/4” | NL56 | 59.1 | 85 | 7 | 13.5 | 10 |
| M60 | — | NL60 | 63.1 | 90 | 7 | 15.2 | 10 |
| M64 | 2 1/2” | NL64 | 67.1 | 95 | 7 | 16.7 | 10 |
| M68 | — | NL68 | 71.1 | 100 | 9.5 | 28.2 | 1 |
| M72 | — | NL72 | 75.1 | 105 | 9.5 | 30.7 | 1 |
| M76 | 3” | NL76 | 79.1 | 110 | 9.5 | 33.3 | 1 |
| M80 | 3 1/8” | NL80 | 83.1 | 115 | 9.5 | 36 | 1 |
| M85 | — | NL85 | 88.1 | 120 | 9.5 | 37.8 | 1 |
| M90 | — | NL90 | 92.4 | 130 | 9.5 | 47.7 | 1 |
| M95 | — | NL95 | 97.4 | 135 | 9.5 | 49.8 | 1 |
| M100 | 4” | NL100 | 103.4 | 145 | 9.5 | 58.9 | 1 |
| M105 | — | NL105 | 108.4 | 150 | 9.5 | 61.3 | 1 |
| M110 | — | NL110 | 113.4 | 155 | 9.5 | 63.5 | 1 |
| M115 | — | NL115 | 118.4 | 165 | 9.5 | 75.3 | 1 |
| M120 | — | NL120 | 123.4 | 170 | 9.5 | 77.9 | 1 |
| M125 | — | NL125 | 128.4 | 173 | 9.5 | 76.6 | 1 |
| M130 | 5” | NL130 | 133.4 | 178 | 9.5 | 79.2 | 1 |
- Øi is the inner diameter and Øo the outer diameter. Washers are supplied in pairs.
- Need a size that is not listed? Contact us and we will check with Nord-Lock.
Supply and downloads
Supply time and documents
Supply time
Supply time depends on size, material and quantity. Send your requirement and we will confirm availability and lead time with your quote.
Ask for a quoteOfficial Nord-Lock datasheet
Free datasheets, brochures and CAD files are available from the Nord-Lock download center.
Open the Nord-Lock download center ↗R Square product PDF
Our original washers PDF with specs, supply details and contacts.
Download Nord-Lock Original Washers PDFFAQ
Common questions
Do I need one pair or two?
One pair under the bolt head for a blind hole. For a through bolt with a nut, use one pair under the head and one pair under the nut.
Do they work with lubricated bolts?
Yes. Lubrication does not affect the locking.
Can Nord-Lock washers be reused?
Yes, in most cases, depending on operating conditions.
Guides
