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Nuts · GB/T 889 / ISO 7040

M18 Nylon Insert Hex Lock Nut Dimensions & Specifications

M18 Nylon Insert Hex Lock Nut Dimensions & Specifications reference image

M18 is one of the standard coarse-thread sizes for nylon insert hex lock nut under GB/T 889 / ISO 7040. The sections below reproduce the dimensional row, list the matching tools and hole sizes, and summarize where this size is normally specified.

M18 Dimensional Row (GB/T 889 / ISO 7040)

SizePitch (mm)Width across flats s (mm)Width across corners e (mm)Total height m (mm)Reference standard
M182.527.030.1418.0ISO 7040 / DIN 985

Spanner & Drive for M18 Nylon Insert Hex Lock Nut — GB/T 889 / ISO 7040 (Series 078)

Drive geometry for M18 Nylon Insert Hex Lock Nut — GB/T 889 / ISO 7040 (Series 078) is given by the row above; match the tool to the listed values.

Common Applications for M18 Nylon Insert Hex Lock Nut — GB/T 889 / ISO 7040 (Series 078)

M18 Nylon Insert Hex Lock Nut — GB/T 889 / ISO 7040 (Series 078) are commonly specified for structural joints, flange connections and heavy equipment foundations.

Installation Tips for M18 Nylon Insert Hex Lock Nut — GB/T 889 / ISO 7040 (Series 078)

  • At M18 the stretch in the bolt becomes the controlling factor — for critical joints, use angle-controlled or stretch-controlled tightening instead of pure torque.

Mating Parts for M18

Pair M18 with the matching M18 bolt or screw, plus a M18 flat washer where required to distribute load on softer materials.

Technical Drawing

Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.

Sends the selected values to the quote form below.

Request a Quote

Adjust the parameters in the drawing above and click "Request this configuration" to send the exact specification straight to this form.

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Specification
Business Information

Dimensions & Specifications (GB/T 889 / ISO 7040)

SizePitch (mm)Width across flats s (mm)Width across corners e (mm)Total height m (mm)Reference standard
M30.55.56.014.0ISO 7040 / DIN 985
M40.77.07.665.0ISO 7040 / DIN 985
M50.88.08.795.0ISO 7040 / DIN 985
M61.010.011.056.0ISO 7040 / DIN 985
M81.2513.014.388.0ISO 7040 / DIN 985
M101.516.017.7710.0ISO 7040 / DIN 985
M121.7518.020.0312.0ISO 7040 / DIN 985
M142.021.023.3614.0ISO 7040 / DIN 985
M162.024.026.7516.0ISO 7040 / DIN 985
M182.527.030.1418.0ISO 7040 / DIN 985
M202.530.033.5320.0ISO 7040 / DIN 985
M243.036.039.9822.0ISO 7040 / DIN 985
M303.546.050.8525.0ISO 7040 / DIN 985
M364.055.060.7929.0ISO 7040 / DIN 985

Frequently Asked Questions

What grip range is typical for M18 structural bolts?

Grip ranges are highly application-dependent at M18. As a guide, choose a length that gives at least 1× the thread diameter engagement in the nut plus 2–3 thread pitches projecting.

What is the height of an M18 nut?

The nominal height of a style-1 ISO 4032 M18 nut is in the spec table on this page. Style-2 (thick) is approximately 1.1× this height; thin (ISO 4035 / DIN 439) is approximately 0.5×.

What is the coarse-thread pitch of M18 for Nylon Insert Hex Lock Nut — GB/T 889 / ISO 7040 (Series 078)?

For M18 the standard coarse pitch is 2.5 mm — this is the value used for Nylon Insert Hex Lock Nut — GB/T 889 / ISO 7040 (Series 078).

What clearance and tapping drill suit M18?

Use a 20 mm clearance hole (ISO 273 medium) for through-fixing, or a 15.5 mm tapping drill for a coarse M18 thread.

How do I request a quotation?

Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day.