SKF Spherical Washer

Specifications

How to choose Fastening Parts

Points to check when selecting, with the values for this product (SKF Spherical Washer).

1. 1. Select a nominal diameter suited to the substrate and load

   The nominal diameter is the outer diameter of the thread. A larger diameter increases pull-out and shear resistance, but it must pass through the hole in the mounted item. Listed examples are 4 mm, 5 mm and 6 mm; determine the size by matching the hole diameter of the bracket and the weight of the suspended equipment.

2. 2. Determine the overall length from item thickness plus required embedment

   The overall length L of listed products is 35 to 80 mm. The remaining length after subtracting the thickness of the mounted item (band or bracket) is the embedment depth into the substrate, so for soft substrates such as ALC panels choose a length that secures sufficient embedment. Also confirm that the screw does not pass through the back of the substrate thickness.

3. 3. Check the thread length engaging the substrate

   The thread length ℓ of listed products is 30 to 55 mm, and this threaded portion provides the holding power. Even with the same overall length, a short threaded section means fewer threads engage the substrate depending on the thickness of the mounted item. Estimate the effective engagement length together with the thickness of the mounted item.

4. 4. Choose the head shape according to the mounting hole and finish

   Flat heads sink into countersunk holes to give a flush surface. Truss heads have a large, low profile and suit holding down brackets or bands with holes that are not countersunk, using their wide bearing surface. Decide based on the hole shape of the mounted item and whether the head may protrude.

5. 5. Verify bearing surface and clearance using head diameter and height

   Head diameter D is in the range of 7 to 12 mm and head height H is 2 to 3.5 mm. If the head diameter is not sufficiently larger than the hole in the mounted item, it cannot hold securely, and head height affects interference with surrounding members or covers. For brackets with slotted holes, confirm that the head diameter reliably exceeds the slot width.

6. 6. Check material and surface treatment for outdoor or humid environments

   Corrosion is a concern for applications outdoors, such as downspout bands. Check the body material (such as stainless steel) and whether anti-corrosion treatment is applied, and watch for galvanic corrosion where the fastener contacts dissimilar metals in the mounting bracket. For structural applications where certified products are specified, as with structural screws, use products that conform to the certified specification.

This guide was written by AI based on the listed products' documents and specification items.

About Fastening Parts and all products

Description

Automatically compensates for angular misalignment between flat surfaces and distributes bolt tension evenly. Available in standard and low-profile designs, and surface-treated versions are also offered.

FAQ

Q. What applications can the SKF Spherical Washer (Series SMSW) be used for?

A. It is a spherical washer that keeps the bolt head and nut face parallel and prevents bolt bending. It is used for bolted joints and the installation of rotating machinery. It automatically compensates for angular misalignment between flat surfaces and distributes bolt tension evenly.

Q. What are the outer diameter, inner diameter, and height ranges of the SKF Spherical Washer (Series SMSW)?

A. The outer diameter D is 33 to 92 mm, and the inner diameter d is 17 to 52 mm. The height H is 60 mm for the standard specification.

Q. What specification variations are available for the SKF Spherical Washer (Series SMSW)?

A. Standard and low-profile designs are available, and surface-treated versions are also offered.

Written by AI based on the content of the source documents.

Source documents

• Catalog SKFメンテナンス製品と潤滑製品 204 pages Open page 100
  Found on: https://azuma-eg.com/catalogue/