+91 97734 41022 sales@exoticalloy.com
ISO 7040 · DIN 982 · ASME B18.16.6 NE

Nylock Nuts Manufacturer in India

A nylon ring that grips the bolt and will not let go. We make nylock nuts, the regular-height nylon-insert lock nuts, to ISO 7040, DIN 982 and ASME B18.16.6 style NE, in steel classes 5, 8 and 10 and stainless A2 and A4. Below: the nut to scale and in section, the dimension tables, how the insert locks, bolt length and a finder.

Request a Quote WhatsApp Sales
  • ISO 9001:2015 certified manufacturer
  • Metric and inch
  • Class 5, 8, 10 · A2 · A4
  • EN 10204 3.1 / 3.2
Stainless steel nylock nuts with white nylon insert rings
ISO 7040 M3 – M36 ASME NE 1/4 – 1-1/2 in Nylon to ~120 °C
Overview

ISO 7040 Nylock Nuts: Manufacturer & Stockist

A nylock nut is a hexagon nut with a nylon ring in a collar on top. The bolt forms its own thread in the ring, and the nylon's grip on the thread keeps the nut from working loose under vibration.

Exotic Alloy manufactures and stocks nylock nuts in Mumbai, India, for machine builders, vehicle and trailer makers, HVAC and electrical panel makers, and fastener distributors. We supply across India and stock for buyers in Zimbabwe, Southern and East Africa, the Middle East and South-East Asia.

Regular height, three standards

ISO 7040 is the international metric standard. DIN 982, the German high type, is withdrawn but still ordered, with spanner sizes one step bigger at M10, M12 and M14. Inch nuts follow ASME B18.16.6 style NE. The thin nylon-insert nuts, DIN 985, ISO 10511 and style NTE, are on nylock jam nuts; for plain nuts see hex nuts and for nylon-insert flange nuts hex flange nuts.

ISO 7040 DIN 982 ASME NE Class 8 & 10 A2 & A4
Nylock nuts at a glance
Metric
ISO 7040 M3–M36; DIN 982 M5–M24
Inch
ASME B18.16.6 NE, 1/4–1-1/2
M10 height
11.9 mm max (ISO 7040)
Insert
Polyamide, to about 120 °C
Classes
5, 8, 10; NE2, NE5, NE8
Stainless
A2-70, A4-70
Related
Thin nylock, all-metal lock, washers
ISO 7040 nylon-insert lock nut M10 to scale in top view, side view and section: 16 mm across flats, at least 17.77 mm across corners, 11.2 to 11.9 mm high overall, with a metal nut body at least 8.04 mm high and a nylon ring held in the collar above it ISO 7040 nylon-insert lock nut M10, to scale e min 17.77 s 16 (spanner) Top: nylon ring in the collar h 11.2–11.9 m min 8.04 Side: hex body + collar bearing face Section nylon ring metal body, full M10 thread The nylon ring has no thread and a bore smaller than the bolt; the bolt forms its own thread in it, and that grip is the locking. Hex body, chamfers and thread to scale; collar and ring proportions schematic (ISO 7040: shape at the maker's discretion). EXOTIC ALLOY
An ISO 7040 M10 nylock nut. A full-strength nut body with the nylon ring above it.
Specification

Nylock Nut Specification

The range we manufacture and stock.

StandardsISO 7040, DIN 982, ASME B18.16.6 NE
SizesM3–M36 (M39 to order); 1/4–1-1/2 in
ThreadMetric coarse 6H; UNC, UNF
Property class5, 8, 10; NE2, NE5, NE8
StainlessA2-70 (304), A4-70 (316)
InsertPolyamide ring, to about 120 °C
Product gradeA to M16, B above (ISO 7040)
FinishPlain, zinc plated, zinc flake
CertificationEN 10204 3.1; 3.2 on request
SupplyBoxed by size, or in sets with bolts and washers
ISO 7040

ISO 7040 Nylock Nut Dimensions

Regular height, metric coarse thread, mm.

ThreadPitch PSpanner s
max / min		e minHeight h
max / min		Nut body m minWrenching mw minBearing dw min
M3 *0.55.5 / 5.326.014.5 / 4.022.151.724.57
M4 *0.77 / 6.787.666 / 5.522.92.325.88
M5 *0.88 / 7.788.796.8 / 6.224.43.526.88
M6110 / 9.7811.058 / 7.424.93.928.88
M81.2513 / 12.7314.389.5 / 8.926.445.1511.63
M101.516 / 15.7317.7711.9 / 11.28.046.4314.63
M121.7518 / 17.7320.0314.9 / 14.210.378.316.63
(M14)221 / 20.6723.3617 / 15.912.19.6819.64
M16224 / 23.6726.7519.1 / 17.814.111.2822.49
M20 *2.530 / 29.1632.9522.8 / 20.716.913.5227.7
M24336 / 3539.5527.1 / 2520.216.1633.25
M303.546 / 4550.8532.6 / 30.124.319.4442.75
M36455 / 53.860.7938.9 / 36.429.423.5251.11

ISO 7040:2012 Table 1, identical to the 1997 edition and to globalfastener's 2012 listing; spanner s and corners e are those of the ISO 4032 plain nut. h overall height, m height of the metal nut body (the ISO 4032 minimum), mw wrenching height. * ISO 7040:2025, the current edition, keeps these figures except at M3 (h max 4.8), M4 (6.5), M5 (6.95) and M20 (23), and adds the six sizes below. The 2025 values come from globalfastener alone; their s and m match ISO 4032:2023.

Sizes added in ISO 7040:2025

ThreadPitch PSpanner sHeight h maxNut body m min
(M7)1119.26.14
(M18)2.52721.215.1
(M22)2.5342518.1
(M27)34129.922.5
(M33)3.55035.727.4
(M39)46041.931.8
DIN 982

DIN 982 Nylock Nuts and the ISO Difference

High type, metric coarse thread, mm. Bold: ISO spanner size differs.

ThreadPitch P
coarse		Spanner s
max / min		e minHeight h
max / min		Nut body m minISO 7040 s / h max
M50.88 / 7.788.796.3 / 64.48 / 6.8
M6110 / 9.7811.058 / 7.74.910 / 8
M7111 / 10.7312.128.5 / 8.26.14–
M81.2513 / 12.7314.389.5 / 9.146.4413 / 9.5
M101.517 / 16.7318.911.5 / 11.148.0416 / 11.9
M121.7519 / 18.6721.114 / 13.6410.3718 / 14.9
M14222 / 21.6724.4916 / 15.312.121 / 17
M16224 / 23.6726.7518 / 17.314.124 / 19.1
M182.527 / 26.1629.5620 / 19.1615.1–
M202.530 / 29.1632.9522 / 20.716.930 / 22.8
M222.532 / 3135.0325 / 23.718.1–
M24336 / 3539.55 *28 / 26.720.236 / 27.1

DIN 982:1987 from globalfastener, fasten.it, Intafast and ITA Fasteners, which agree except for misprints. * M24: fasten.it gives e min 39.95 mm; globalfastener, Intafast and the ISO 4032 value for a 36 mm hexagon give 39.55 mm, which we use. Fine-thread DIN 982 nuts, such as M10 x 1.25 and M12 x 1.5, are made to order.

M10 nuts to scale: plain ISO 4032 nut 16 mm across flats and up to 8.4 mm high; DIN 985 nylon-insert thin nut 17 mm and 10 mm; DIN 982 17 mm and 11.5 mm; ISO 7040 16 mm and 11.9 mm M10 lock nuts against a plain nut, to scale (side view across corners) 8.4 mm high ISO 4032 plain nut s 16 mm 10 mm high DIN 985 (thin) s 17 mm 11.5 mm high DIN 982 s 17 mm 11.9 mm high ISO 7040 s 16 mm Heights are maximum values. DIN 985 is the thin type (successor ISO 10511); DIN 982 and ISO 7040 are regular height. EXOTIC ALLOY
Same thread, four nuts. At M10 the nylon collar makes the nut 1.6 to 3.5 mm taller than a plain nut.
ASME NE

ASME B18.16.6 Style NE Nylon Insert Locknuts

Regular height, UNC and UNF, inches.

SizeTPI
UNC / UNF		Across flats
max / min		Corners minHeight
max / min		Hex height minBearing min
1/420 / 28.439 / .430.488.328 / .298.225.416
5/1618 / 24.502 / .489.557.359 / .329.250.475
3/816 / 24.564 / .551.628.468 / .438.335.534
7/1614 / 20.627 / .616.698.468 / .438.324.597
1/213 / 20.752 / .736.840.609 / .579.464.712
9/1612 / 18.877 / .861.982.656 / .626.469.830
5/811 / 18.940 / .9221.051.765 / .735.593.890
3/410 / 161.064 / 1.0521.191.890 / .860.7421.033
7/89 / 141.252 / 1.2391.403.999 / .969.7901.230
18 / 121.440 / 1.4271.6191.078 / 1.016.8251.418
1-1/87 / 121.627 / 1.6141.8331.203 / 1.141.9301.605
1-1/47 / 121.815 / 1.8012.0461.422 / 1.3601.1251.793
1-3/86 / 122.008 / 1.9732.2591.609 / 1.5471.2821.962
1-1/26 / 122.197 / 2.1592.4731.640 / 1.5781.3132.148

ASME B18.16.6 style NE from globalfastener (2008 and 2017 listings), BoltingSpecialist and JC Fasteners. Grades NE2, NE5 and NE8 go with SAE grade 2, 5 and 8 bolts. Across corners: globalfastener's 2017 listing prints slightly smaller minimums at ten sizes (for example 0.482 against 0.488 in at 1/4); the other sources and its 2008 listing give the values shown. JC Fasteners lists height minimums 0.003 to 0.008 in lower; we use the matching values of the other three.

Locking & use

How Nylock Nuts Lock and How to Fit Them

How a nylon-insert lock nut locks, M10 section: on the left the bolt has reached the nylon ring, whose bore is smaller than the bolt; on the right the nut is tightened on two plates and the bolt has formed its thread through the ring and stands two to three pitches above the nut How it locks: M10 nut in section 1. Running on: the nut turns freely until the bolt reaches the nylon ring bore smaller than the bolt 2. Tightened: the bolt forms a thread in the nylon, which grips its flanks 2 to 3 pitches past the nut The nylon grips the thread flanks and resists turning even when the clamp load drops: the prevailing torque. EXOTIC ALLOY
Free running, then locking. The nut turns freely until the bolt reaches the ring, then needs a spanner all the way down.
  • Bolt length: clamped parts + washers + nut height h + 2 to 3 thread pitches, so the bolt passes right through the ring.
  • Strength: the metal body is a full ISO 4032 nut, so a class 8 nylock nut carries an 8.8 bolt.
  • Heat: keep below about 120 °C; above that use an all-metal lock nut.
  • Tighten with a spanner on the hex; the ring is not a bearing face.
  • Grip falls with each removal: refit only in non-critical joints, never where a joint is safety-critical.
  • Keep the ring away from solvents and paint stripper.
Overall height h max of nylon-insert lock nuts M5 to M24: ISO 7040 and DIN 982 regular heights against the DIN 985 thin type Overall height h max, mm: ISO 7040, DIN 982 and DIN 985 ISO 7040 DIN 982 DIN 985 (thin) 0 5 10 15 20 25 30 M5 ISO 7040: 6.8 mm M5 DIN 982: 6.3 mm M5 DIN 985 (thin): 5 mm M5 M6 ISO 7040: 8 mm M6 DIN 982: 8 mm M6 DIN 985 (thin): 6 mm M6 M8 ISO 7040: 9.5 mm M8 DIN 982: 9.5 mm M8 DIN 985 (thin): 8 mm M8 M10 ISO 7040: 11.9 mm M10 DIN 982: 11.5 mm M10 DIN 985 (thin): 10 mm M10 M12 ISO 7040: 14.9 mm M12 DIN 982: 14 mm M12 DIN 985 (thin): 12 mm M12 M14 ISO 7040: 17 mm M14 DIN 982: 16 mm M14 DIN 985 (thin): 14 mm M14 M16 ISO 7040: 19.1 mm M16 DIN 982: 18 mm M16 DIN 985 (thin): 16 mm M16 M20 ISO 7040: 22.8 mm M20 DIN 982: 22 mm M20 DIN 985 (thin): 20 mm M20 M24 ISO 7040: 27.1 mm M24 DIN 982: 28 mm M24 DIN 985 (thin): 24 mm M24 ISO 7040:2012, DIN 982 and DIN 985 (1987). Hover a bar for the value. EXOTIC ALLOY
Regular against thin. ISO 7040 and DIN 982 carry a full-height body; DIN 985 is the thin type.

Sources differ: some guides ask for 2 pitches of bolt past the nut, others 3; the finder shows both. The insert's upper limit of about 120 °C is given by Würth and AIMS Industrial; lower limits quoted range from −40 °C to −70 °C.

Finder

Nylock Nut Finder: Size, Bolt Length & Heat Check

Pick the nut, enter the joint and the service temperature; get the dimensions, the bolt length, a heat check and the order line.

Nut & joint

Dimensions from the tables on this page (ISO 7040:2012 values; 2025 changes are flagged). Bolt length = clamped parts + washers + nut height h max + 2 pitches (shortest) or 3 pitches. Round up to the next stock length. Heat check against about 120 °C for the nylon.

Result
11.9
mm high, max
34.9
mm shortest bolt
Spanner:16 mm (corners 17.77)
Nut body:8.04 mm min + collar
Bolt, 3 pitches:36.4 mm
Heat check:60 °C: fine
Designation:1000 pcs nut ISO 7040 – M10 – 8

Materials

Nylock Nut Materials & Finishes

Nut bodyClass / gradeFinishPairs with
Carbon steel5 · 8 · 10 (ISO 7040, DIN 982)Zinc plated, zinc flake, plainBolts up to 5.8, 8.8, 10.9
Carbon steel, inchNE2 · NE5 · NE8Zinc plated, plainSAE grade 2, 5, 8 bolts
Stainless A2 (304)A2-70Plain, as in the photoA2-70 bolts; food plants, outdoors
Stainless A4 (316)A4-70PlainA4-70 bolts; marine and chemical areas

ISO 7040 gives property classes 5, 8 and 10 from M5 (class as agreed below M5), with stainless grades selectable from ISO 3506-2; the insert is non-metallic, for example polyamide. Coatings follow ISO 4042 (electroplating) or ISO 10683 (zinc flake).

Stainless
A2-70 · A4-70

As in the photo.

304316
Carbon steel
Class 5 · 8

Zinc plated as standard.

1035
Hardened steel
Class 10 · NE8

Quenched and tempered.

1045
Manufacturing

How Our Nylock Nuts Are Made

1

Material

Steel or stainless wire with heat certificate.

2

Form

Hex body and collar cold formed.

3

Tap

Thread tapped through the body.

4

Treat & plate

Heat treated for class 10; plated before the insert goes in.

5

Insert

Nylon ring pressed in, collar rolled over.

6

Test

Thread, height and prevailing torque checked.

Applications

Where Our Nylock Nuts Are Used

Machinery

Guards, frames and motor mounts under vibration.

Vehicles & trailers

Body panels, brackets and suspension parts.

HVAC

Fans, blowers and duct supports.

Electrical

Panels, cable trays and busbar supports.

Agriculture

Implements that shake loose plain nuts.

Food equipment

Stainless A2 and A4 nuts on wash-down machines.

Quality & testing

Nylock Nut Inspection & Certification

CheckMethodApplied to
ThreadGO / NOT GO plug gauges, before the insertEvery lot
Spanner, heightCalipers against h max / min and sEvery lot
Prevailing torqueTorque on and off a test bolt (ISO 2320 / ASME B18.16.6)Every lot
Proof loadISO 898-2 / ISO 3506-2Every heat-treatment batch
MaterialHeat certificate, PMI for stainlessEvery heat
CoatingThickness gaugePlated lots

Every shipment includes

  • EN 10204 3.1 certificate
  • Lot number on every box
  • Packing list by size

On request

  • EN 10204 3.2 with third-party inspection
  • Prevailing torque test report
  • Sets with bolts and washers
FAQ

Nylock Nut Questions, Answered

A hexagon nut with a nylon ring held in a collar on top. The ring has no thread and a bore smaller than the bolt, so the bolt forms its own thread in it as the nut is tightened. The nylon grips the thread flanks and resists turning, even if the joint loosens. The regular-height types are ISO 7040, DIN 982 and ASME B18.16.6 style NE.

Height and spanner size. At M10, ISO 7040 is up to 11.9 mm high on a 16 mm hexagon, DIN 982 up to 11.5 mm on a 17 mm hexagon, and DIN 985, the thin type, up to 10 mm on 17 mm. ISO and DIN spanner sizes also differ at M12 (18 against 19 mm) and M14 (21 against 22 mm).

16 mm across flats, at least 17.77 mm across corners, 11.2 to 11.9 mm high overall, with a metal nut body at least 8.04 mm high and an M10 x 1.5 thread.

Long enough to pass right through the nylon ring and stand 2 to 3 thread pitches above the nut: clamped parts plus washers plus the nut height h max plus 2 to 3 pitches. For an ISO 7040 M10 nut on 20 mm of clamped parts: 20 + 11.9 + 3 to 4.5 = 34.9 to 36.4 mm, so a 40 mm bolt.

The nylon loses some grip every time the nut is taken off. In a non-critical joint a nut can be refitted if it still needs a spanner to turn on; in a critical joint, fit a new nut.

The polyamide insert is rated to about 120 °C. Above that it softens and the nut loses its grip, so use an all-metal lock nut. Makers quote lower limits between -40 °C and -70 °C.

ISO 7040 nuts from M5 come in property classes 5, 8 and 10 (below M5 the class is agreed). Stainless nuts come in A2-70 and A4-70. Inch style NE nuts come in grades NE2, NE5 and NE8. Match the nut to the bolt: class 8 nuts for bolts up to 8.8, class 10 for 10.9.

Yes, in its 2025 edition. It keeps the 2012 dimensions from M6 to M36 except M20, which is now up to 23 mm high instead of 22.8 mm, makes M3 to M5 a little taller, and adds M7, M18, M22, M27, M33 and M39. DIN 982 and DIN 985 have been withdrawn but are still widely stocked.
Get Rapid Pricing & Availability

Request a Quote for Nylock Nuts

Tell us the standard, size, thread, class or grade, finish and quantity. We respond within 2 to 4 business hours.

Inquiry Received!
Thank you. Our technical sales team will contact you shortly.