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Washers · GB/T 852

M18 Wedge / Taper Washer Dimensions & Specifications

M18 Wedge / Taper Washer Dimensions & Specifications reference image

M18 Wedge / Taper Washer (GB/T 852) are specified by thread size, length and head dimensions. The M18 row from the standard is reproduced below, followed by the drill sizes, spanner size and torque values used when installing this size.

M18 Dimensional Row (GB/T 852)

For bolt sizeInner diameter d1 (mm)Outer diameter d2 (mm)Mean thickness t (mm)SlopeReference standard
M1818.5397.21:6DIN 6917 / GB/T 853

Spanner & Drive for M18 Wedge / Taper Washer — GB/T 852 (Series 084)

Drive geometry for M18 Wedge / Taper Washer — GB/T 852 (Series 084) is given by the row above; match the tool to the listed values.

Common Applications for M18 Wedge / Taper Washer — GB/T 852 (Series 084)

M18 Wedge / Taper Washer — GB/T 852 (Series 084) are commonly specified for high-load load-spreading on structural joints.

Installation Tips for M18 Wedge / Taper Washer — GB/T 852 (Series 084)

  • 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

A M18 flat washer pairs with a M18 bolt/screw and matching M18 nut.

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.

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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 852)

For bolt sizeInner diameter d1 (mm)Outer diameter d2 (mm)Mean thickness t (mm)SlopeReference standard
M33.561.21:6DIN 6917 / GB/T 853
M44.581.61:6DIN 6917 / GB/T 853
M55.5112.01:6DIN 6917 / GB/T 853
M66.5132.41:6DIN 6917 / GB/T 853
M88.5173.21:6DIN 6917 / GB/T 853
M1010.5224.01:6DIN 6917 / GB/T 853
M1212.5264.81:6DIN 6917 / GB/T 853
M1414.5305.61:6DIN 6917 / GB/T 853
M1616.5356.41:6DIN 6917 / GB/T 853
M1818.5397.21:6DIN 6917 / GB/T 853

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.

Which washer dimensions matter most for M18?

For a flat washer, the outside diameter (the bearing surface) and the thickness control how the load is spread under the head and how much elastic preload is preserved. The inside diameter must clear the bolt body but not be so large that the head bears mostly on the washer's outer rim.

What is the coarse-thread pitch of M18 for Wedge / Taper Washer — GB/T 852 (Series 084)?

For M18 the standard coarse pitch is 2.5 mm — this is the value used for Wedge / Taper Washer — GB/T 852 (Series 084).

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.